Molecular dynamics-based refinement of nanodiamond size measurements obtained with dynamic light scattering

The determination of particle size by dynamic light scattering uses the Stokes–Einstein relation, which can break down for nanoscale objects. Here, we employ a molecular dynamics simulation of fully solvated 1–5 nm carbon nanoparticles for the refinement of the experimental data obtained for nanodiamonds in water by using dynamic light scattering. We performed molecular dynamics simulations in differently sized boxes and calculated nanoparticles diffusion coefficients using the velocity autocorrelation function and mean-square displacement. We found that the predictions of the Stokes–Einstein relation are accurate for nanoparticles larger than 3 nm while for smaller nanoparticles the diffusion coefficient should be corrected and different boundary conditions should be taken into account.     

Computations with quasiseparable polynomials and matrices

In this paper, we survey several recent results that highlight an interplay between a relatively new class of quasiseparable matrices and univariate polynomials. Quasiseparable matrices generalize two classical matrix classes, Jacobi (tridiagonal) matrices and unitary Hessenberg matrices that are known to correspond to real orthogonal polynomials and Szegö polynomials, respectively. The latter two polynomial families arise in a wide variety of applications, and their short recurrence relations are the basis for a number of efficient algorithms. For historical reasons, algorithm development is more advanced for real orthogonal polynomials. Recent variations of these algorithms tend to be valid only for the Szegö polynomials; they are analogues and not generalizations of the original algorithms.     

Parent-Infant Synchrony and the Social-Emotional Development of Triplets.

To study the social-emotional development of triplets, 23 sets of triplets, 23 sets of twins, and 23 singleton infants (N=138) were followed from birth to 2 years. Maternal depression and social support were assessed in the postpartum period, mother-infant and father-infant interaction and the home environment were observed at 3 months, a separation-reunion episode and a maternal interview were conducted at 12 months, and infant behavior problems were evaluated at 24 months. Lower parent-infant synchrony was observed for triplets. Triplets showed less distress during maternal separation and less approach at reunion. Mothers reported lower adjustment and differentiation among siblings for triplets than for twins. Higher internalizing problems were reported for triplets, and the triplet with intrauterine growth retardation showed the poorest outcomes. Behavior problems were predicted by medical risk, maternal depression, parent-infant synchrony, infant approach, and mother adjustment. Discussion focuses on developmental risk when the exclusivity of the parent-infant relationship is compromised. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On a carbon nanostructure-based thermoelectric converter with record parameters

Semiconductors - There is a new idea to enhance the Seebeck coefficient using electron drag by a heat flux and decrease the thermal conductivity by heat dissipation at the interfaces between...     

Intervention programs for premature infants. How and do they affect development?

Over the past 30 years, a variety of intervention programs for the enhancement of the neurodevelopmental status of premature infants have been implemented with confusing outcomes. In addition, diametrically different forms of therapy that rest on contrasting theories have led, paradoxically, to similar results. This article systematically examines and analyses the various modes of therapy and their underlying theoretical mechanisms. Skin-to-skin contact (kangaroo care) is suggested as the intervention that most logically meshes the premature infant's need to develop state regulation while facilitating sequential sensory development and promoting mother-infant attachment.     

Changes in the mechanism of heat transfer in passing from microparticles to nanoparticles

On the basis of experimental data on thermal conduction and sound velocity in composites obtained by sintering detonation nanodiamonds with the crystallite size of 4–5 nm and diamond micropowders with a grain size of about 10 μm at a high pressure (5–7 GPa) and high temperature (1200–1800°C), mechanisms of heat transfer in such structures are suggested. These mechanisms are shown to be different in composites of micro- and nanoparticles. In composites of micrometer particles, the conventional macroscopic mechanism of phonon propagation is active. In composites with a grain size of a few nanometers, the main contribution comes from thermal resistance on grain boundaries.     

Wound healing and complementary therapies: a review

A series of five innovative experiments conducted by Wirth et al. which examined the effect of various complementary healing interventions on the reepithelialization rate of full thickness human dermal wounds was assessed as to specific methodological and related factors. The treatment interventions utilized in the series included experimental derivatives of the Therapeutic Touch (TT), Reiki, LeShan, and Intercessory Prayer techniques. The results of the series indicated statistical significance for the initial two experiments and nonsignificance or reverse significance for the remaining three studies. This review article examines the methodological designs of the series of studies, along with the TT practitioners' phenomenologically based journal reports, to provide potential contributing correlative factors for the differential results obtained. These factors include: (1) methodological design restrictions, (2) a transference/inhibitory effect (3) the influence of experimental assistants, (4) healer visualization /imagery techniques, (5) variations in subject populations, and (6) a potential cancellation effect. While the placebo controlled double-blind methodological designs used in the series were as stringent as those used in other fields of scientific inquiry, the overall results of the experiments were inconclusive in establishing the efficacy of the treatment interventions for accelerating the rate of reepithelialization of full thickness dermal wounds.     

Neonatal blood pressures

Arterial blood pressures were taken by the Doppler ultrasound method in 134 unselected mature neonates (birthweights 2,600-3,900 grams) who were managed in the same manner after birth. Blood pressures were measured at 3-5, 10 and 30 minutes of life and, if indicated, intermittently during the next 24-48 h. Left and right arm pressures were identical or differed by only 1-2 mm Hg. Lower than normal blood pressures were found in 4 groups of infants: those born by cesarean section, those recovering from intrauterine asphyxia, those exposed to maternal anti-hypertensive therapy, and those whose mothers received thiopental within four minutes of delivery. Return of the low pressures to within the normal range was fastest following thiopental induction in the absence of fetal asphyxia and slowest after antihypertensive therapy.     

A real QZ algorithm for structured companion pencils

We design a fast implicit real QZ algorithm for eigenvalue computation of structured companion pencils arising from linearizations of polynomial rootfinding problems. The modified QZ algorithm computes the generalized eigenvalues of an \(N\times N\) structured matrix pencil using O(N) flops per iteration and O(N) memory storage. Numerical experiments and comparisons confirm the effectiveness and the stability of the proposed method.