Electrical linewidth test structures fabricated in monocrystallinefilms for reference-material applications

The physical widths of reference features incorporated into electrical linewidth test structures patterned in films of monocrystalline silicon have been determined from Kelvin voltage measurements. The films in which the test structures are patterned are electrically insulated from the bulk-silicon substrate by a layer of silicon dioxide provided by SIMOX (Separation by the IMplantation of OXygen) processing. The motivation is to facilitate the development of linewidth reference materials for critical-dimension (CD) metrology-instrument calibration. The selection of the (110) orientation of the starting silicon and the orientation of the structures' features relative to the crystal lattice enable a lattice-plane-selective etch to generate reference-feature properties of rectangular cross section and atomically planar sidewalls. These properties are highly desirable for CD applications in which feature widths are certified with nanometer-level uncertainty for use by a diverse range of CD instruments. End applications include the development and calibration of new generations of CD instruments directed at controlling processes for manufacturing devices having sub-quarter-micrometer features     

Mass hysteria: one syndrome or two?

BACKGROUND: It has been suggested that mass hysteria can be divided into two syndromes; one with predominant features of anxiety and the other with predominant abnormalities of motor behaviour. In the former condition, prior tension is absent and spread is by visual contact. In the latter, prior tension is present, initial cases can be identified and spread is gradual. METHOD: The development and resolution of neurological symptoms in 156 Nigerian school girls were studied and a diagnosis of 'mass hysteria' made. RESULTS: The signs and symptoms manifested by the school girls during the outbreak of illness had features of both 'anxiety' and 'motor' predominant forms of mass hysteria. CONCLUSIONS: Although there may be two patterns of symptom presentation in mass hysteria, other supposedly discrete features overlap. This weakens the argument that there are two separate syndromes.     

An expert decision support system for network routing: a case study

The paper presents a case study of the development of an expert decision support system which uses simple heuristic methods for fast determination of routes for simultaneous signals in a transmission network of limited capacity. It illustrates how heuristic solutions can be embodied in a model-based DSS and how the standard decision support literature, although intuitively appealing, provides little practical assistance in system construction or classification     

Nursing performance measures go public

Over 100 years ago, Florence Nightingale showed caregivers how to analyze mortality data to improve their clinical processes. The nurses of today are facing a new performance measurement challenge. Consumers of health care services want information that will help them compare quality among providers. This article describes the types of nursing performance measures most appropriate to include on these public-oriented report cards and several issues that influence report card design and dissemination.     

p21WAF1/Cip1 expression is associated with cell differentiation but not with p53 mutations in squamous cell carcinomas of the larynx

The anti-metastatic effect of Z-100, an immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis, was investigated in mice bearing B16 melanoma cells. Treatment of BF10 mice implanted with high metastatic B16F10 melanoma cells with a 10 mg/kg dose of Z-100 resulted in the reduction of experimental pulmonary metastasis as compared with that of BF10 mice treated with saline. The number of pulmonary metastatic colonies in BF1 mice (mice implanted with low metastatic B16F1 melanoma cells) was greatly increased after the inoculation of CD4+ CD11b+ CD281+ TCR alphabeta+ type 2 T cells (F10-Th2 cells) derived from BF10 mice, while only a few metastatic colonies were demonstrated in lungs of BF1 mice inoculated with naive CD4+ T cells. However, the numbers of metastatic colonies in BF1 mice were not increased when they were inoculated with the F10-Th2 cell fraction derived from Z-100-treated BF10 mice and the generation of F10-Th2 cells in BF10 mice was effectively suppressed by the Z-100 treatment. These results suggest that Z-100 inhibits pulmonary metastasis of B16 melanoma through the regulation of tumor-associated Th2 cells, which are a key cell in the acceleration of tumor metastasis.     

A twin study of dental dimension. II. Independent genetic determinants

To demonstrate the presence of independent genetic determinants of multiple correlated tooth dimensions from twin data, a multivariate analysis was performed on the covariance matrices of monozygotic and dizygotic within-pair differences for mesiodistal and buccolingual dimensions of 28 teeth of the secondary dentition. The results provided strong evidences that the correlation among tooth dimensions is primarily genetic in origin, probably attributable to the pleiotropic action of either independent genes or groups of genes. Among the genetic factors that were identified, one appeared to affect the maxillary teeth in general while a second influenced primarily the anterior mandibular teeth. There was a striking tendency for homologous measurements on the right and left sides to be associated with the same genetic factor. In contrast, genetic determination of the maxillary and mandibular dentition seemed to be independent of each other, and a wider range of genetic factors were found to influence the mandibular than the maxillary teeth, suggesting that a differential degree of evolutionary stability may have been achieved in the teeth of the two jaws.     

Inhibition of insulin degradation by nonsuppressible insulin-like activity

Nonsuppressible insulin-like activity, provided by three sources, was evaluated for its effect on the proteolytic degradation of insulin utilizing insulin protease obtained from rat liver homogenate as well as liver cell membranes. All three preparations of nonsuppressible insulin-like activity were found to be competitive inhibitors of insulin degradation. In addition human plasma was fractionated yielding an acetone precipitate which was found to have nonsuppressible insulin-like activity and to be a competitive inhibitor of insulin protease.     

Co-oligopeptides of glycine and aromatic amino acids with variable distance between the aromatic residues. IV. Spectroscopic properties of tryptophan-containing peptides in a cyclohexane phase

L-Tryptophan, L-tryptophanylglycine, glycyl-L-tryptophan, glycyl-L-tryptophanylglycine and glycyl-L-tryptophanylglycylglycyl-L-tryptophanylglycine have been transferred from an aqueous solution (generally 0.1 M NaOH) to cyclohexane, using the quaternary ammonium salt trioctylmethyl ammonium chloride (NR+4Cl-, soluble in cyclohexane but not in water) as the transporting agent. The spectroscopic properties of L-tryptophan and tryptophan-containing peptides have been studied in the cyclohexane phase. With respect to the aqueous solutions, ultraviolet absorption spectra are characterized by a considerable red shift of the absorption maxima and by a hypochromicity of up to 10%. Fluorescence spectra generally show emission maxima which are characteristic of polar environments, accompanied by a significant enhancement of the quantum yield. CD spectra have also been investigated for all peptides and compared with those for aqueous systems reported in preceding publications. All these spectral changes cannot be attributed solely to the cyclohexane solvent effect. It is suggested that these anomalous spectral properties of the tryptophan-containing compounds in the cyclohexane-NR+4 solution are due to the influence the electrostatic field of the ion pair has on the indole chromophore. The possible implications of this finding for the spectroscopic properties of aromatic residues buried in the polar interior of proteins are discussed.