Conjunctival nevi in Denmark 1960-1980. A 21-year follow-up

The clinicopathological characteristics of 343 naevi of the conjunctiva were studied. A significant increase in the number of naevi excised per year was observed. This may have been caused by an increased exposure to actinic rays. An approximately even distribution was found between the three main locations: caruncle, limbal area and eye ball. Intrastromal naevi were excised at a higher median age than compound naevi, and the lowest median age at excision was for junction naevi, which is in accordance with the known histopathological nature of naevi. Recurrence occurred in nine patients (2.7%), and one had transformed into a malignant melanoma. Eight of the recurring naevi were located in the limbal area. Eight of the nine patients were women, suggesting hormonal factors as a possible cause. Recommendations for the handling of conjunctival naevi are given, based on the present findings and on previous reports.     

Heptadecapeptide gastrin: measurement in blood by specific radioimmunoassay

The characteristics are described of an antibody (designated L6) which has virtually absolute specificity for heptadecapeptide gastrin. This antibody binds G17, but does not bind peptide fragments or molecular forms of gastrin comprising G17 with either amino acid deletions, or additions, at the carboxyl- and amino-terminals. In serum from patients with Zollinger-Ellison syndrome the only form of gastrin revealed by L6 was compatible with G17, and there was good agreement between estimated G17 concentrations in serum analyzed by gel filtration and by direct radioimmunoassay using L6. Using L6 in conjunction with antibodies specific for carboxyl- and amino-terminals of G17 it has been possible to measure concentrations of different forms of gastrin in serum of normal subjects after a meal in greater detail than previously possible. After a light meal consisting of eggs, toast, and Oxo, serum concentrations of G17 measured by L6 increased to a peak 20 min after feeding (delta gastrin, 19 pmoles per liter; n = 17). In contrast, concentration of G34 peaked at 50 min (delta gastrin, 27 pmoles per liter). Small amounts of amino-terminal fragments of G17 were present throughout the digestive period. Applying the known ratio of biological potencies of G34 and G17 for stimulation of acid secretion in man, it is estimated that G17 accounts for about 75% of the biological activity in blood after a meal, even though G34 is present in higher molar concentrations.     

Fetal MEG redistribution by projection operators

The fetal magnetoencephalogram (fMEG) is measured in the presence of large interference from the maternal and fetal magnetocardiograms. This interference can be efficiently attenuated by orthogonal projection of the corresponding spatial vectors. However, the projection operators redistribute the fMEG signal among sensors. Although redistribution can be readily accounted for in the forward solution, visual interpretation of the fMEG signal topography is made difficult. We have devised a general, model-independent method for correction of the redistribution effect that utilizes the assumption that we know in which channels the fMEG should be negligible (such channels are distant from the known fetal head position). In a simplified case where the fMEG can be explained by equivalent current dipoles, the correction can also be obtained from fitting the dipoles to the fMEG signal. The corrected fMEG signal topography then corresponds to the dipole forward solution, but without orthogonal projection. We illustrate the redistribution correction on an example of experimentally measured flash evoked fMEG.     

An improved snare system for the nonsurgical retrieval of intravascular foreign bodies

We have modified a snare technique originally described for transcolonoscopic removal of colonic polyps for the retrieval of intravascular foreign bodies. The key difference from other snare techniques is the employment of a wire snare with a crimp in its midportion that enables the formation of a loop in a plane perpendicular to the axial direction of the guiding catheter. With this technique we have quickly removed a variety of objects from the right heart and pulmonary arteries in four patients.     

Anthocyanin Degradation in the Presence of Furfural and 5-Hydroxymethylfurfural

The influence of furfural (F) and 5-hydroxymethylfurfural (HMF) on degradation of cyanidin-3-glucoside (CG) was investigated in blackberry juice and in a citrate buffer model solution (pH 3,45) at 24°, 50° and 70°C. Presence of 0.012 M F or HMF accelerated pigment degradation. The acceleration was directly temperature-dependent, more pronounced in fruit juice, and considerably decreased in nitrogen. CG and HMF disappearance – but not the interaction between these compounds – followed the first-order reaction kinetics. The influence of formaldehyde (Fa) acetaldehyde (Aa) and benzaldehyde (Ba) on the stability of CG was investigated in blackberry juice. CG degradation effect of non-furane aldehydes (0.012 M) was Fa < Aa < Ba. CG and cyanidine (C) reactivities were studied by condensation with F and examination of molecular electrone properties (cyanidine, keto-pseudobase, anhydrobase, chalcone). Furfural did not react with CG but it did react with C. Electron charge distribution points to anhydrobase as the tautomeric form of C most reactive to F. Possible mechanisms of C decomposition in presence of F are proposed and discussed.     

Optimal lower bounds on the contribution margin in the case of stochastic order arrival

In customer order driven production, decisions on the acceptance of customer orders usually have to be based on variable costs and contribution margins (abbreviated CM), since in the short term only these quantities can be influenced. If we assume that customer orders arrive according to a stochastic process and that the decisions on order acceptance have to be made on each order separately, a customer order usually should be accepted only if its contribution margin exceeds a positive lower bound. This paper shows by means of a stochastic model that, under certain assumptions, this lower bound on the contribution margin can be determined using full costing, provided that the available capacity (constant over time) and the arrival process are balanced. This insight justifies, to a certain extent, the use of full costs to support decisions on the short-term production volume, which is a behaviour that can be observed in practice rather frequently. We also demonstrate the extension of the modelling approach to state-dependent lower bounds on the contribution margin.     

Synthesis of an ammonium ionophore and its application in a planar ion-selective electrode

A modular technique was used to synthesize an ammonium-selective ionophore based on a cyclic depsipeptide structure. The ionophore was incorporated into a planar ion-selective electrode sensor format and the selectivity tested versus a range of metal cations in a commercial clinical diagnostic "point-of-care" instrument. Four sensor membrane formulations were tested, all of which consisted of plasticized PVC. Formulations differed as to the type of plasticizer used and whether an ionic additive was present. It was found that the membrane containing the polar plasticizer nitrophenyl octyl ether in the absence of ionic additive exhibited near-Nernstian behavior (slope, 60.1 mV/decade at 37 degrees C) and possessed high selectivity for ammonium ion over lithium and the divalent cations, calcium and magnesium (log K(POT)NH4+(j) = -7.3, -4.4, and -7.1 for lithium, calcium, and magnesium ions, respectively). The same membrane also exhibited sodium and potassium selectivity that was comparable to that reported for nonactin (log K(POT)NH4+(j) = -2.1 and -0.6 for sodium and potassium, respectively, compared to -2.4 and -0.9 in the case of nonactin). Membranes containing the less polar plasticizer, dioctyl phthalate, showed sub-Nernstian behavior (slope, <50 mV/decade at 37 degrees C). In all cases, the presence of the ionic additive potassium tetrakis(4-chlorophenyl)borate substantially reduced the selectivity observed. The flexible modular synthetic technique developed and reported here will allow the cyclic depsipeptide structure to be tuned for optimum selectivity.     

Complex dewetting scenarios captured by thin-film models

In the course of miniaturization of electronic and microfluidic devices, reliable predictions of the stability of ultrathin films have a strategic role for design purposes. Consequently, efficient computational techniques that allow for a direct comparison with experiment become increasingly important. Here we demonstrate, for the first time, that the full complex spatial and temporal evolution of the rupture of ultrathin films can be modelled in quantitative agreement with experiment. We accomplish this by combining highly controlled experiments on different film-rupture patterns with computer simulations using novel numerical schemes for thin-film equations. For the quantitative comparison of the pattern evolution in both experiment and simulation we introduce a novel pattern analysis method based on Minkowski measures. Our results are fundamental for the development of efficient tools capable of describing essential aspects of thin-film flow in technical systems.