Caring for the older patient, Part I: The relationship of theory to practice

This is the first article of a four-part series on gerontology and its applications to the care of elderly patients in nuclear medicine. The series includes discussions about the theories of aging, approaches to meeting the special needs of the elderly and ethical dilemmas in caring for the elderly. It also reviews anatomical and physiological changes associated with aging and the role of nuclear medicine studies in caring for the elderly. Upon completion of this article, the reader should be able to: (a) describe the aging U.S. population by citing demographic data; (b) identify the theories of aging and distinguish their major characteristics; (c) differentiate a gerontologic approach from a geriatric approach in caring for the elderly; and (d) recognize factors important to the delivery of effective care for the elderly.     

A computational theory of executive cognitive processes and multiple-task performance: Part I. Basic mechanisms.

A new theoretical framework, executive-process interactive control (EPIC), is introduced for characterizing human performance of concurrent perceptual-motor and cognitive tasks. On the basis of EPIC, computational models may be formulated to simulate multiple-task performance under a variety of circumstances. These models account well for reaction time (RT) data from representative situations such as the psychological refractory-period procedure. EPlC's goodness of fit supports several key conclusions: (a) At a cognitive level, people can apply distinct sets of production rules simultaneously for executing the procedures of multiple tasks; (b) people's capacity to process information at "peripheral" perceptual-motor levels is limited; (c) to cope with such limits and to satisfy task priorities, flexible scheduling strategies are used; and (d) these strategies are mediated by executive cognitive processes that coordinate concurrent tasks adaptively. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Human C-peptide. Part I: Radioimmunoassay

Synthetic human C-peptide bearing a Tyrosine group at its amino end is labelled with 125iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results are compared applying both methods. Antiserum to synthetic human C-peptide (without Tyrosine) which was partially compared to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pigs concerning antibody production. The so-called "hook effect" phenomenon is observed in setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated with the anxion exchange resin Amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum.     

Interdendritic Spacing: Part I. Experimental Studies

Directional solidification experiments have been carried out in a succinonitrile-5.5 mol pct acetone system to characterize dendrite tip radius and interdendrite spacings as functions of growth rate and temperature gradient in the liquid. A maximum in primary dendrite spacing as a function of growth rate is observed, and this maximum is found to occur at the dendrite-cellular transition velocity. A scaling law is shown to exist between the secondary dendrite arm spacing, λ₂, near the tip and the dendrite tip radius, p, which is λ₂/ρ = 2.2 ± 0.3. Experimental results on ρ have been found to agree with the theoretical model based on the marginal stability criterion. This paper is based on a presentation made at the symposium “Establishment of Microstructural Spacing during Dendritic and Cooperative Growth” held at the annual meeting of the AIME in Atlanta, Georgia on March 7, 1983 under the joint sponsorship of the ASM-MSD Phase Transformations Committee and the TMS-AIME Solidification Committee.     

Dendritic growth of undercooled nickel-tin: Part I

Solidification of undercooled Ni-25 wt pct Sn alloy was observed by high-speed cinematography and results compared with optical temperature measurements. Samples studied were rectangular in cross-section, and were encased in glass. Cinematographic measurements were carried out on samples undercooled from 68 to 146 K. These undercoolings compare with a temperature range of 199 K from the equilibrium liquidus to the extrapolated equilibrium solidus. At all undercoolings studied, the high-speed photography revealed that solidification during the period of recalescence took place with a dendrite-like front moving across the sample surface. Spacings of the apparent “dendrite” were on the order of millimeters. The growth front moved at measured velocities ranging from 0.07 meters per second at 68 K undercooling to 0.74 meters per second at 146 K undercooling. These velocities agree well with results of calculations according to the model for dendrite growth of Lipton, Kurz, and Trivedi. It is concluded that the coarse structure observed comprises an array of very much finer, solute-controlled dendrites.     

Freezing diagrams: Part I. Development and Implications for glass formability

Prediction of equilibrium and metastable phase formation for a particular system, after cooling from the liquid state, is possible by the development of afreezing diagram. the freezing diagram is constructed by consideration of kinetic as well as thermodynamic factors. The kinetic factors divide the diagram into three zones. These are: (1) where long-range diffusion can occur; (2) where short-range diffusion only is possible; and (3) where no significant diffusion is possible in the liquid ahead of the solid-liquid interface. The solid-liquid interface temperature,T ₁ , determines which diffusion process occurs.T ₁ is the vertical axis of the diagram plotted against composition. the microstructure that results is predicted by the thermodynamic possibilities in each kinetic zone. In the first zone, the equilibrium phase diagram is applicable. The second zone only allows massive transformations to single-phase structures, and their limits are defined byT _o lines. The third zone is below the glass transition temperature, and any liquid retained to this zone is quenched-in and becomes a glass. The development, significance, and limitations of the freezing diagram are discussed.     

Forging limits for an aluminum matrix composite: Part I. Experimental results

Forging limits in a discontinuously reinforced aluminum (DRA) matrix composite, 2014 Al/15 vol pct A1^-2O^-3, were determined by compressing samples of various cylindrical geometries under different conditions of temperature, strain rate, and lubrication and measuring the limit strains attained prior to incipient crack formation. In some cases, circumferential grids were machined on the sample surface to obtain the local fracture strain states. Crack formation was caused by the secondary tensile stresses; however, crack propagation was relatively slow and somewhat more severe at 300 °C than at 400 °C. The forging limit of the composite was found to be higher at 400 °C than at 300 °C and also higher at slower strain rates. The plane-strain forging limit of the composite at 300 °C and a strain rate of 0.5 s”1 was less than 0.05, while that of the matrix was higher than 0.5. It was found that the forging limits can be influenced by the depth of the circumferential grids and can be lower than those for the smooth surface samples. Formerly Graduate Student, the University of Michigan     

Bioelectronic noses: a status report. Part I

The present state of the art to record or mimic electronically the human senses of olfaction and taste is characterized. In this part I, an introduction to our present understanding in the development of electronic and bioelectronic noses is given. Finally the natural olfactory system is described in detail.     

Acquired scalp alopecia. Part I: A review

In this two-part series we review the acquired scalp alopecias. A broad spectrum of diseases result in alopecia. In this first part we provide a framework for the assessment and diagnosis of scalp hair loss, and begin covering the individual conditions. The non-scarring alopecias covered include effluvium, androgenetic alopecia, alopecia areata, trichotillomania, and loose anagen syndrome. The scarring alopecias cause permanent pilosebaceous follicle loss; the lymphocyte-associated scarring alopecia described encompasses lichen planopilaris, discoid lupus erythematosus, pseudopelade, and follicular mucinosis. Part II will cover the neutrophil-associated and infiltrative processes causing scarring alopecia followed by the medical management of alopecia. There is particular reference to newly described conditions and progress in the understanding of older conditions. More recently characterized conditions include the loose anagen syndrome, chronic telogen effluvium, and the frontal fibrosing variant of lichen planopilaris.     

Pattern integrations in young depressed women: Part I

Five nitro musk compounds widely used in cosmetics and detergents were examined for DNA-damaging and mutation-inducing properties. For this purpose two short-time assays were used, the SOS chromotest and the Salmonella/mammalian microsome test. Musk ambrette showed mutagenicity in Salmonella typhimurium TA 100 requiring metabolic activation by rat liver postmitochondrial supernatant (S9) but it lacked mutagenicity in the absence of S9 and genotoxicity in the SOS chromotest. Musk xylene, musk ketone, musk moskene and musk tibetene showed neither mutagenicity nor genotoxicity in the presence and absence of S9.     

Cellular and dendritic growth: Part I. Experiment

An Al-4.1 mass pct Cu alloy was unidirectionally solidified under various growth rates. Features, such as tip radius of curvature, primary arm spacing, and tip concentration were measured as functions of growth rate. Dependence of tip radius on growth rate was different between cells and dendrites. Measured tip radius and primary arm spacing were maximum at the cellular-dendritic transition. Tip concentration, however, monotonously decreases with growth rate. Linear relationships between tip radius and characteristic dimensions of dendrites like core diameter, half length of tip arc, and the first secondary arm spacing are obtained to determine what affects growth rate, convection, and gravity segregation. Experimental results are compared with current theoretical models for dendrite growth under controlled solidification. It was determined that the measured tip radius is larger than that of theoretical predictions at fast growth rate, but the measured tip concentration is in good agreement with theoretical predictions.     

Novel cytokine release inhibitors. Part I: Triterpenes

Tripterine and closely related triterpenoid derivatives as IL-1 beta release inhibitors are discussed.     

Culture and test session behavior: Part I.

The relationship between culture (circumscribed by race, ethnicity, country of origin, language, and/or social class) and test session behavior (TSB) on group and individual tests of intelligence and/or achievement is evaluated with respect to the quality of evidence offered in support of knowledge claims. Four relevant categories in the literature are identified: (1) speculative theories, (2) studies of standardized measures of test session behavior, (3) TSB experimental research, and (4) research in cross-cultural test development. In Part I of a two-part series, key literature from the first two categories is reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oxidation of cobaltite: Part I. process mineralogy

The control of arsenic is important in oxidation roasting and leaching of cobaltite. Oxidation roasting below 823 K did not show any crystal structural change in cobaltite, but heating to 923 K yielded Co-As-oxide, whose composition is varied. Direct oxidation of cobaltite to cobalt oxides with traces of arsenic was observed by roasting at 1023 K or above. The distribution of arsenic within the particles gradually decreased from the outer region to the center of the particles. The arsenic concentration within the particles decreased with the increase of temperature, suggesting temperature dependence on arsenic removal from the lattice of cobaltite. In this article, the process mineralogy of the oxidation of cobaltite is presented at various temperatures. The results from X-ray diffraction (XRD) analysis, reflected light microscopic analysis, and scanning electron microscopic analysis of the roasted cobaltite concentrates together with a rationalized thermodynamic analysis are presented.     

Neonatal hypoglycemia, Part I: Background and definition

Hypoglycemia in the neonate remains a common problem. The association of low blood glucose concentrations and abnormal development has prompted extensive research into the anticipation, evaluation, and treatment of neonatal hypoglycemia. Glucose homeostasis in the fetus and neonate is a developmentally regulated dynamic process involving a number of intricate physiologic mechanisms. In addition, the determination of glucose concentrations is dependent upon both the type of tissue analyzed and the limitations of the specific method employed. The complexity of glucose metabolism makes it difficult to precisely define "normal" and "abnormal" glucose levels in preterm and term neonates.     

Flow fields in electromagnetic stirring of rectangular strands with linear inductors: Part I. theory and experiments with cold models

A model is presented to compute the electromagnetic force fields and fluid flow fields in electromagnetic stirring of continuously cast strands with rectangular cross-section. The model involves the solution of the Maxwell equations, the Navier-Stokes equations, and the transport equations for the turbulence characteristicsk and e. The procedure of depth-averaging is applied in the treatment of several three-dimensional flows. Experiments were performed to check the computations using mercury as fluid. The spatial distribution of the magnetic induction and of the force density was determined for the laboratory inductor used in the stirring experiments. The flow velocity was measured photographically or with a drag probe, respectively. The agreement between experimental and theoretical data was found to be within 25 pct. It is concluded that the theory is sufficiently reliable to predict the flow fields in electromagnetic stirring of steel strands. In Part II of this paper the model is applied to analyze stirring situations in continuous casting of steel. Formerly with Institut für Allgemeine Metallurgie, Technische Universit?t Clausthal     

Personality disorders: model for conceptual approach and classification. Part I: General model

In this article we present data suggesting that one core deficit in personality represents a common dimension extending across most categories of personality disorders (PDs), whereas clinically discrete syndromes classified as PDs in DSM IIIR are categorical maladaptive types related orthogonally to the common borderline dimension. In a sample of 121 subjects with PDs and 67 controls, persons with PDs and without PDs manifested similar profiles on the Millon Clinical Multiaxial Inventory (MCMI) scales for various behavior styles. Conversely, the two groups consistently differed with respect to the MCMI borderline scale: in contrast to non-PD persons, those with PDs were strikingly more borderline and typically scored above 75 points (the latter has been established as the cut off for the diagnosis of Borderline PD). Likewise, persons with PDs scored significantly higher on the Diagnostic Interview for Borderlines than the control group. These results suggest that: i) most symptoms usually considered typical of the borderline personality characterize other PDs as well; ii) borderline features seem to be characteristic of persons with PDs and can be used to distinguish PDs vs. non-PDs. Therefore, symptoms widely regarded as typical of the borderline personality characterize other PDs as well. This shared dimension may explain the overlap in categorical diagnoses of individual PDs. Moreover, this shared dimension may be efficiently used as the classificatory principle for PDs. In Part II of this article, we present a model that classifies deviant behaviors in a systematic way, i.e., combines three levels of functioning (normal, neurotic, and borderline) with a limited number of categories of (mal) adaptive behavior types.