Metal ion/buffer interactions. Stability of binary and ternary complexes containing 2-[bis(2-hydroxyethyl)amino]-2(hydroxymethyl)-1,3-propanediol (Bistris) and adenosine 5'-triphosphate (ATP)

The acidity constant of protonated 2-[bis(2-hydroxyethyl)amino]-2(hydroxymethyl)-1,3-propanediol (Bistris) has been measured. The influence of hydroxo groups on the basicity of Bistris and related bases is discussed. The interaction of Bistris with the metal ions (M2+) Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Pb2+ was studied by potentiometry and spectrophotometry in aqueous solution (I = 1.0 M, KNO3; 25 degrees C) and the stability constants of the M(Bistris)2+ complexes were determined. Unexpectedly Ca(Bistris)2+ is the most stable among the alkaline earth ion complexes (log KCaCa(Bistris) = 2.25; the corresponding values for the Mg2+, Sr2+ and Ba2+ complexes are 0.34, 1.44 and 0.85, respectively). The ions of the 3d series follow the Irving-Williams sequence: log KMnMn(Bistris) = 0.70, for Cu2+, 5.27 and Zn2+ 2.38. Ternary complexes containing ATP4- as a second ligand were also investigated: the values for delta log KM (= log KM(ATP)M(ATP)(Bistris) -log KMM(Bistris) are in general negative (e.g. delta log KCa = -0.40 or delta log KCu = -1.65), thus indicating that the interaction of Bistris with M(ATP)2- is somewhat less pronounced tan with M2+. However, even in mixed-ligand systems, complex formation may still be considerable, hence great reservations should be exercised in employing Bistris as a buffer in systems containing metal ions. Moreover, in several cases delta log KM is relatively high [for Mg2+-ATP4- -Bistris even positive], indicating some cooperativity between the coordinated ligands, possibly hydrogen-bond formation. Distributions of the complexes in dependence on pH are given, and the structures of the binary M(Bistris)2+ and the ternary M(ATP) (Bistris)2- complexes are discussed. The participation of Bistris hydroxo groups in complex formation is evident.     

Effects of performance expectancy and self-focused attention on social interaction.

Investigated the impact of performance expectancies and self-focused attention on social performance in mixed-sex dyads of 48 undergraduate men with self-reported moderate social anxiety on a modified Social Avoidance and Distress Scale. Ss were divided into 2 groups on the basis of their high or low performance expectancies. Ss were asked to respond to several self-report questionnaires before and after making a telephone call lasting 4–5 min to a female confederate for the purpose of getting acquainted. Results show that half of the Ss in each expectancy group performed in the presence of a self-focusing stimulus (video-camera). When anxiety level was controlled for, focus of attention alone had a very limited effect on performance. Expectancy had a significant influence on social performance, but only if Ss were self-focused. Thus confident Ss were rated by judges as more socially skilled than were doubtful Ss, but only when the camera was present. The interaction between these variables parallels previous research by C. S. Carver et al (see record 1980-32489-001) and Carver and M. F. Scheier (see record 1980-25774-001) and supports the self-regulation model of Carver and Scheier (1983). (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mid-Infrared Remote Sensing Systems and Their Application to Lithologic Mapping

Mid-infrared remote lithologic mapping by emittance and by reflectance are assessed in laboratory experiments. The emittance spectra of various rocks and minerals, measured in the 8-13, ?m atmospheric transmission window, are compared with reflectance data measured in the range of 9.2-11.2 Am using a line-tuned CO2 laser. We conclude that the reflectance data are more useful for lithologic discrimination than the passive emittance data. An experimental laser suitable for terrain mapping from a low-flying aircraft is described. The low-pressure longitudinal discharge CO2 laser has a rotating mirror to scan the diffraction grating and generates 90 bursts of pulses per second. Each 1-ms burst contains 92 pulses at 92 CO2 laser wavelengths. The mean output power is 12 W and the average pulse power is 370 W. With that power, and using incoherent detection, a signal-to-noise ratio of better than 100: 1 should be obtained from terrain with an albedo of 0.01 at a height of 500 m.     

Genetic hearing loss with preauricular sinus and branchiogenic fistula

A mother and her two children had hearing loss associated with bilateral preauricular sinus and branchiogenic fistula. All six cochleas studied showed two turns rather than 2 1/2 turns. Complete studies including audiometry, tympanotomy findings, and temporal bone polytomography of these anomalies are reported. Similar cases reported in the English literature are reviewed. It seems that all previous cases may have had an abnormal cochlea as was seen in these cases.     

The oncogenic effect of fibrous dust. Animal experiments and their relationship with human carcinogenesis

The results after intraperitoneal injection of fibrous and granular dusts in rats suggest, that the fibrous shape of asbestos is the cause of its cancerogenicity. Fibrous dusts other than asbestos (for example glass fibers) may induce tumours, when their diameters are like that of asbestos and the fibres are invariable in tissue. It is supposed, that a fibre with a diameter less than 1 mum and a length greater than 3 mum has a cancerogenic effect. The interpretation of the experimental results considering the cancerogenesis in humans is discussed, especially concerning the effect of fibrous glass.     

Computer-based data entry for nurses in the ICU

Efforts are being made to improve the efficiency and quality of care in intensive care units (ICUs) at Latter Day Saints Hospital. The ICUs have been computerized, and the collection, storage, and presentation of patients' data have been improved. Nurses use computers for entering clinical data and plans for nursing care, and the effects of these changes on the work patterns of nurses in the ICU have been evaluated. Contrary to our expectation, our studies showed a decrease in the proportion of time that nurses spent in direct patient care (from 49.1% to 43.2%) and an increase in the proportion they spent entering clinical data (from 18.2% to 24.2%) after computerization. These changes, however, were attributed to a decrease in the severity of patients' illnesses, rather than the availability of the computer. There was no measurable difference in the proportion of time spent at other nursing activities.