Intraventricular chemotherapy in neonatal meningitis

All of 16 infants with neonatal meningitis treated during a 30-month period were found to have accompanying ventriculitis at the time of the initial ventricular puncture. Fifteen of these infants were caused by gramm-negative organisms. All infants received antibiotics systemically and intraventricularly via an implanted ventriculostomy reservoir or by direct ventricular injection. Antibiotic concentrations within the ventricular fluid were monitored during chemotherapy; the complications encountered during treatment are discussed. Fifteen infants survived the infection; of these, seven infants were normal at follow-up examinations. In our experience intraventricular chemotherapy as an adjunct to systemic administration of antibiotics has greatly reduced the mortality rate in neonatal meningitis.     

Intracell c.c.d. programmable correlator

Four eight sample programmable intracell charge correlators have been operated in parallel to give sixteen levels of weighting. The device is capable of accepting both analogue and digital input signals with the variable weighting function being effected digitally. Output characteristics illustrating the uniformity between the cells and the linearity of summation are presented.     

Crystal defects in manganese (II) oxide and their influence on antiferromagnetic behaviour

Antiferromagnetic domain walls in synthetic MnO crystals are found by electron microscopy to exist at temperatures up to 25°K aboveT _N. Precipitates of Mn₃O₄ and dislocations associated with them impede the motion of walls and are the main cause of their retention aboveT _N. On cooling to belowT _N, such defects apparently can also provide the basis of a memory for the re-establishment of earlier domain configurations. Electron diffraction shows that the manganous oxide is non-stoichiometric and at room temperature possesses both short-range order and a superlattice (witha _sup=2a₀). The superlattice is believed to be magnetic in origin but the short-range order is manifest as structural microdomains, probably with ordering of cation vacancies. The microdomains occur as lamellae parallel to {111}, with an average thickness of 30 Å.     

Calcium-phytate complex formation studies

A calcium-phytate complex has been prepared. The chemical composition indicates that five calciums combine per phytate molecule. The solubility product of this calcium-phytate is about 10^?22 in 0.2 M KCl.     

Aircraft noise and children: Longitudinal and cross-sectional evidence on adaptation to noise and the effectiveness of noise abatement.

Assessed the impact of noise on attentional strategies, learned helplessness, performance on cognitive tasks, and blood pressure. Third and 4th graders were tested on the same measures twice, with a 1-yr interval between sessions. Longitudinal data were used to determine whether Ss adapted to aircraft noise over the 1-yr period and to assess the effectiveness of noise abatement interventions introduced in a number of noise-impacted classrooms. Additional cross-sectional data are presented to provide further information on the utility of noise abatement. In general, there was little evidence for adaptation to noise over the 1-yr period. Noise abatement had small ameliorative effects on cognitive performance, Ss' ability to hear their teachers, and school achievement. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sialic acid-depleted red cells following acute myocardial infarction

A reduction of red cell SA in patients following acute myocardial infarction is reported and the effects of SA-depleted red cells on cardiac index and alveolar capillary blood flow in the dog are described. The mean red cell SA in 26 patients following acute myocardial infarction was 0.021 +/- 0.001 compared with a mean of 0.031 +/- 0.002 mumol./0.1 ml RBC in 12 normal subjects (p less than 0.01). In five dogs injected with neuraminidase, an enzyme which removes SA from the red cell membrane, a 43% decrease in mean cardiac index from 2.3 +/- 0.22 to 1.3 +/- 0.16 (p less than 0.01) occurred. In films of the pulmonary microcircuation the mean widths of typical alveolar capillary beds decreased 42.6% +/- 5% (p less than 0.01). In three other dogs, autotransfusion with SA-depleted stored blood resulted in a 25% decrease in mean cardiac index from 2.0 +/- 0.21 to 1.5 +/- 0.21 (p less than 0.2), and a 21.7% +/- 0.9% (p less than 0.01) decrease in mean widths of typical alveolar capillary beds. We conclude that a reduction of red cell SA follows acute myocardial infarction and that SA-depleted red cells decrease cardiac index and alveolar capillary blood flow in the dogs.     

Slow crack growth in brittle materials under dynamic loading conditions

The failure of materials due to slow crack growth, under dynamic loading conditions, is analyzed in terms of crack velocity, stress intensity relationships. It is shown that this type of analysis can fully describe the failure characteristics for both constant strain-rate and constant stress-rate loading. The analysis is used to predict the variations of strength and subcritical crack growth with strain-rate and stress-rate. Application of the analysis to several ceramic systems give data which are entirely consistent with available experimental data.

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Zusammenfassung Der Bruch von Material durch langsame Rißausdehnung, unter dynamischer Beanspruchung wird in Hinsicht der Beziehung zwischen der Rißausdehnungsgeschwindigkeit und der Spannungsintensität untersucht. Man zeigt daß diese Form von Untersuchung die Bruchbegebenheiten vollständig beschreiben kann sowohl für eine Belastung, sowohl unter konstantem Verformungsgrad, als unter konstantem Spannungsgrad. Die Untersuchung wird zur Voraussagung der Änderungen der Festigkeit und des subkritischen Rißwachstums mit dem Verformungs- und dem Spannungsgard. Die Anwendung der Untersuchung auf verschiedene Keramiksysteme ergibt Ergebnisse die vorzüglich mit bestehenden Versuchsergebnissen übereinstimmen.

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Résumé La rupture des matériaux due à une propagation lente d'une fissure sous des charges dynamiques est analysée en termes de relations entre la vitesse de propagation et l'intensité des contraintes.On montre que le type d'analyse envisagé peut complètement décrire les caractéristiques d'une rupture sous charges caracterisées par une vitesse constante de déformation, ou par une vitesse constante de tension.On utilise l'analyse pour prédire les variations de la résistance et la propagation subcritique de la fissure en fonction de la vitesse de déformation ou de mise sous tension.L'application de l'analyse à divers systèmes céramiques fournit des données qui satisfont entièrement les données expérimentales disponibles.