Exchange bias and Verwey transition in Fe5C2/Fe3O4 core/shell nanoparticles

This report presents new findings of exchange bias and related structural and magnetic properties in iron carbide/magnetite (Fe₅C₂/Fe₃O₄) core/shell nanoparticles. The exchange bias emerges from an energetic landscape, namely a first-order phase transition-the Verwey transition at 125 K, during which the Fe₃O₄ shell changes from the cubic to monoclinic structure. The phase transition leads to the exchange bias because it results in abrupt changes in magnetocrystalline anisotropy and exchange coupling. Another unique phenomenon identified in this composite system is enhanced magnetic coercivity due to the uniaxial anisotropy of the monoclinic phase. An analysis of the correlations between the observed phenomena is given based on the temperature dependence of the coercivity, the exchange bias field values, and the Verwey transition temperature.

Magnetic-field-induced self-assembly of FeCo/CoFe2O4 core/shell nanoparticles with tunable collective magnetic properties

Self-assembly of nanoparticles into ordered patterns is a novel approach to build up new consolidated materials with desired collective physical properties. Herein, nanoparticle assemblies of composition-modulated bimagnetic nanoparticles have been produced via slow evaporation of their colloidal suspension in the absence or presence of magnetic fields. The assemblies obtained in the presence of the magnetic fields exhibit oriented nanoparticle chains in face-centered cubic superlattice structures, compared with the hexagonal closed-packed superlattice obtained without the magnetic field. The oriented structure has an alignment of the easy magnetization axis along the chains. This alignment leads to enhanced intra-superlattice interactions. As a result, the field-induced assembly displays collective magnetic properties with significantly enhanced magnetic anisotropy, remanent magnetization and coercivity. It is also found that the bimagnetic FeCo/CoFe2O4 core/shell nanostructure enhances the intra-particle interaction and thus is beneficial for the growth of oriented assembly of nanoparticles. Furthermore, the collective magnetic behavior is evidenced by the observation of a superferromagnetic-like magnetization relaxation in the ac-susceptibility curves.

REVISITING DESTRUCTION IN "THE USE OF AN OBJECT"

"The Use of an Object" (1969a) has been widely recognized as among Winnicott's great papers and has deservedly received a good deal of attention. Much of that attention has focused on the importance that the paper gives to the role of destruction in bringing about the experience of externality. Yet the nature of that destruction has too often been assumed based on Winnicott's earlier writings. In the view that follows from that, destruction is equated with the aggression that fails to destroy the object, and the experience of externality is regarded just as the result of that failure. In offering a rereading of "The Use of an Object," the author suggests that, while this aspect of aggression/destruction indeed plays an important role in the establishment of externality, it is only part of the story, and that the central contribution of "The Use of an Object" is Winnicott's attempt to offer a new theory of primitive destruction, one that provides an impulsive basis for separation/externality itself. This theory and Winnicott's ongoing attempts to develop it after "The Use of an Object" led him to rethink the very nature of the drives.

Daclizumab high-yield process reduced the evolution of new gadolinium-enhancing lesions to T1 black holes in patients with relapsing-remitting multiple sclerosis

BACKGROUND AND PURPOSE

In the SELECT study, treatment with daclizumab high-yield process (DAC HYP) versus placebo reduced the frequency of gadolinium-enhancing (Gd(+) ) lesions in patients with relapsing-remitting multiple sclerosis (RRMS). The objective of this post hoc analysis of SELECT was to evaluate the effect of DAC HYP on the evolution of new Gd(+) lesions to T1 hypointense lesions (T1 black holes).

METHODS

SELECT was a randomized double-blind study of subcutaneous DAC HYP 150 or 300 mg or placebo every 4 weeks. Magnetic resonance imaging (MRI) scans were performed at baseline and weeks 24, 36 and 52 in all patients and monthly between weeks 4 and 20 in a subset of patients. MRI scans were evaluated for new Gd(+) lesions that evolved to T1 black holes at week 52. Data for the DAC HYP groups were pooled for analysis.

RESULTS

Daclizumab high-yield process reduced the number of new Gd(+) lesions present at week 24 (P = 0.005) or between weeks 4 and 20 (P = 0.014) that evolved into T1 black holes at week 52 versus placebo. DAC HYP treatment also reduced the percentage of patients with Gd(+) lesions evolving to T1 black holes versus placebo.

CONCLUSIONS

Treatment with DAC HYP reduced the evolution of Gd(+) lesions to T1 black holes versus placebo, suggesting that inflammatory lesions that evolved during DAC HYP treatment are less destructive than those evolving during placebo treatment.

MOTILITY, AGGRESSION, AND THE BODILY I: AN INTERPRETATION OF WINNICOTT

Among the central ideas associated with the name of Winnicott, scant mention is made of motility. This is largely attributable to Winnicott himself, who never thematized motility and never wrote a paper specifically devoted to the topic. This paper suggests both that the idea of motility is nonetheless of central significance in Winnicott's thought, and that motility is of central importance in the development and constitution of the bodily I. In elaborating both these suggestions, the paper gives particular attention to the connections between motility, continuity, aggression, and creativity in Winnicott's work.

CD56(bright) natural killer cells and response to daclizumab HYP in relapsing-remitting MS

Objective:

To assess the relationship between CD56^bright natural killer (NK) cells and multiple sclerosis (MS) disease activity in patients with relapsing-remitting MS treated with daclizumab high-yield process (DAC HYP).

Methods:

Data were from patients enrolled in a 52-week randomized, double-blind, placebo-controlled study of DAC HYP and its extension study. Assessments included relationships of CD56^bright NK cell numbers (identified using fluorescence-activated cell sorting) at weeks 4 and 8 with the numbers of new or newly enlarging T2-hyperintense lesions between weeks 24 and 52 and the annualized relapse rate.

Results:

In DAC HYP–treated patients but not placebo-treated patients, the numbers of CD56^bright NK cells increased over 52 weeks of treatment, and their numbers at weeks 4 and 8 predicted the number of new or newly enlarging T2-hyperintense lesions between weeks 24 and 52 of treatment (p ≤ 0.005 for each comparison). Similar but nonsignificant trends were observed between CD56^bright NK cell counts and the annualized relapse rate in DAC HYP–treated patients. DAC HYP–treated patients who showed lower levels of expansion of CD56^bright NK cells still developed fewer new or newly enlarging T2-hyperintense lesions than placebo-treated patients during the first year of treatment.

Conclusions:

CD56^bright NK cells appear to mediate some of the treatment-related effects of DAC HYP, but their numbers do not account for the full effect of DAC HYP on MS-related outcomes.

Are people with intellectual disabilities just another customer? Interviews with business owners and staff

Descriptive information on the views of business people towards the presence of persons with intellectual disabilities as customers was reported. We interviewed 89 individuals representing a range of shops and local amenities in four urban and four country regions in Queensland, Australia. We also systematically examined the influence of degree of intellectual disabilities by interviewing employees in shops near community residential facilities for persons with mild/moderate and those near facilities for persons with severe/profound intellectual disabilities. A third group of businesses not located near any such residential facilities served as a control group. Overall, results suggest that business people had few special concerns related to interactions with customers who have intellectual disabilities.

Visual behaviour and dyadic interaction between people with intellectual disability and people who are non-disabled

Patterns of visual dominance in human interaction have been studied by a number of authors. The purpose of the present research was to investigate the implications of these studies for interaction between people who are disabled and people who are non-disabled. It was predicted that disability would differentiate the two groups, with non-disabled partners dominating the visual interaction. Two studies are reported. The first looked at visual interaction through the two looking modes of looking while listening and looking while speaking between 16 dyads where one partner was intellectually disabled and the other non-disabled. In the second study, eight subjects who were intellectually disabled and who had participated in the first study interacted with another person who had an intellectual disability. Their looking modes were then compared between conversing with a non-disabled partner in study 1 and with those of their partner with intellectual disability in study 2. The outcome of the studies showed that subjects who were intellectually disabled did not discriminate in looking mode between partners of different intellectual levels. Conversely, subjects who were non-disabled spoke and looked significantly more when conversing with their partner who was intellectually disabled. It has been argued that overlooking and overspeaking could arise from the need for the non-disabled person to gain some sign of affiliation from their partner, or alternatively, that it might reflect a dominant non-disabled person attempting to facilitate a cooperative style.

Individual differences in story comprehension and recall of poor readers

This study sought to identify poor readers and characterise weaknesses in their knowledge and use of story structure in comprehension and recall. Eighty year 3 children, 20 good readers and 60 poor readers, were selected from an initial pool of children based on factor analysis of scores from three measures of reading ability. The poor readers were then divided into relatively homogeneous subgroups, using eight additional measures of language-reading comprehension, according to a numerical classification procedure. This procedure helped identify specific weaknesses in their language-reading comprehension. All children listened to three stores and retold the stories under free and probe recall conditions. Story recalls were analysed using the STein and Glenn story grammar. Comparison of recalls between the good readers and each of the subgroups of poor readers showed that poor readers in two subgroups evidenced reduced sensitivity to story structure. The children in these subgroups recalled less of the stories overall, recalled less information from story grammar categories to varying extents, and showed patterns of category recall that differed from those of normal readers. Children in one of the subgroups also displayed poor perception of causal relations across story episode boundaries. These results provide evidence of marked heterogeneity in poor readers' story comprehension and recall. Certain subgroups of poor readers may have qualitatively different problems processing stories, relative to other poor readers, which may require a more concerted approach to instruction in story structure.

A survey of aggressive behaviour among a population of persons with intellectual disability in Queensland

A survey was conducted on aggressive behaviour within a population of 2412 persons with intellectual disability in Queensland, Australia. Two hundred and sixty-one individuals were identified who engaged in at least one form of aggressive behaviour, yielding an overall prevalence of 11%. The relative prevalence of aggressive behaviour was higher among institutionalized persons (35%) when compared to those living in group homes (17%) or other community-based facilities (3%). The aggressive behaviour sample included a higher percentage of males (64%). Most were described as functioning in the severe/profound (54%) or moderate (31%) range of intellectual disability with one-third having no intelligible speech. Two-thirds of the sample received medication for their challenging behaviour, while only one-third had behavioural programmes. Eighty per cent engaged in three or more forms of aggression. Many also displayed self-injury (34%) or property destruction (30%). Surveys of aggressive behaviour may prove useful for coordinating services.

The failed and the inadvertent: art history and the concept of the unconscious

The history of art-historical responses to psychoanalysis has yet to be written. Art historians have imported a wide variety of psychoanalytic concepts, and psychoanalysis continues to be a major interpretive resource for the discipline of art history. But beyond the core of art-historical texts that are directly and explicitly influenced by psychoanalysis is a much larger, and I think more important, class of texts that do not cite psychoanalytic concepts, but would nevertheless not be possible without psychoanalysis and especially the fundamental concept of the unconscious. This paper examines the ways that the idea (or notion) of the unconscious affects current thinking about the control artists have over their works; I argue that, in this more general sense, psychoanalysis has tended to help art historians to take away artists' control and awareness of their own work, replacing it with the model of artists as workers largely unaware of what they do. Against this I argue that artists who are imagined to 'preside over their work with their eyes open' can be more interesting subjects, both historically and psychologically.

1993 Governance Award recipients announced

In honor of outstanding service to hospitals and the community, two trustees of Michigan hospitals were awarded the 1993 Hospital Governance Award at the Michigan Hospital Association's Fall Medical Staff-Trustee-Administrator Forum. Each year, the MHA presents the Hospital Governance Award to recognize trustees who demonstrate exceptional service based on overall leadership, overall contributions, and improved community relations. This year's forum was held at the Grand Traverse Resort in Traverse City. James E. Coleman, chairman of the board of directors of Pennock Healthcare System, Hastings, and Alan R. Ryan, chairman of the board of trustees of Saint Mary's Community Health Care System, Grand Rapids, were named the 1993 Governance Award winners.

Relationship between in vivo skin blanching and in vitro release rate for betamethasone valerate creams

Betamethasone valerate creams from two firms were evaluated using the skin blanching procedure. In both studies, the same cream formulation exhibited significantly higher blanching compared to the other product. An in vitro release rate was determined for these betamethasone valerate cream products using a diffusion cell system, with a cellulose acetate membrane and a 60% ethanol:water receptor medium. The release rate (flux) of betamethasone valerate was higher for the higher blanching formulation and was statistically different from the other product. The integrity of the cellulose acetate membrane in 60% ethanol:water mixture was ascertained using hydrocortisone cream product. The in vitro drug release method, using a diffusion cell system and a synthetic membrane, can serve as a good quality control test method for topical creams.

In vitro release of hydrocortisone from topical preparations and automated procedure

The in vitro drug release profile of hydrocortisone (HC) from creams, ointments, and lotions has been determined using an automated procedure. A diffusion cell system and commercially available synthetic membranes were utilized for the studies. The use of a synthetic membrane obviates the problems associated with using skin membranes. Uniform creams and ointment samples for determining release rate profile were prepared by using the teflon mask. Automated sampling avoids operator artifacts. The automated technique developed for determining the in vitro release rate profile of the drug from creams, ointments, and lotions using a diffusion-cell system appears to be a reasonable and practical procedure for assuring batch-to-batch uniformity of topical drug products.

Analysis of in vitro dissolution of whole vs. half controlled-release theophylline tablets

Controlled-release (CR) drug products dissolve more slowly than conventional-release products, reflecting their quality of sustaining a prolonged therapeutic effect. A frequent practice with scored tablets when only half the dosage is desired is to divide the tablet at the score mark and administer only half of the product. The dissolution characteristics of the divided tablets are unknown. It is only an assumption that the halved tablet behaves similarly to the whole tablet both in vitro and in vivo. A series of in vitro dissolution analyses was performed on whole and half CR theophylline tablets from different manufacturers. Statistical tests were carried out between the dissolution results of whole and those of halved tablets to determine whether the mean overall percentages dissolution (averaged over sampling times) were similar and whether the patterns of percentage dissolution over time were similar. The dissolution of halved tablets was slightly faster compared to that of intact (whole) tablets. However, these small differences were not large enough to cause concern or to require bioavailability studies.

Prevalence of hyperkinesis: a comparison of three rating scales

Three rating scales with different items and modes of rating were used to assess the prevalence of hyperactivity among 1,908 children in 7 primary (elementary) schools. Teachers rated all the children in their classes. The number of children found to be hyperactive according to Conners rating scale was 5.6 percent using a cut-off of 2 standard deviations above the mean, or 12 percent using the American cut--off of 15. The Queensland rating scale gave a hyperactivity rate of 7.5 percent, and the Pittsburg scale a rate of 8.9 percent. The overlap of the rating scales gave 3.5 percent and the sum of those identified was 12 percent. More children were found to be hyperactive in lower socio--economic areas. Variation in the children thought to be hyperactive presents a problem for research, but the impact of difficult children in the classroom must not be underestimated.

Monitoring of unfavorable reproductive outcome (URO) among occupationally exposed groups

In the Negev Region of Israel, population 300,000, with a centralized health care and health data system, we propose to monitor associations of occupational exposure with the following URO (approximate rates in parenthesis): infertility (10%), spontaneous abortion (10%), stillbirth (1%), pregnancy complications (5%), specific birth defects (1%), all birth defects (5%), low birth weight (5%), neonatal morbidity (5%); all URO (25%). Critical covariates include smoking, age, contraceptive use, coexisting disease, parity, spouse exposures, and past reproductivity history. Currently exposed women are estimated to include 150 in hospital operating rooms, 200 laboratory workers, 75 chemical production workers and 20 in mercury thermometer factory; men include 5000 in chemical production, 1000 in agricultural chemical use, 100 in chemical laboratories and 200 in university and hospital laboratories. Adjusting for expected turnover rates, we estimate that overall exposures which have risks of increased URO will include about 5000 men and 1000 women. Since priority in research resources goes to most feasible detection and prevention combinations, we define and examine "minimal detectable risk ratios" based on expected populations sizes and incidences for a two year cohort study with estimated one "exposed pregnancy" per five person years in this young population. We tabulate these risk ratios using a cutoff for false positive at p=0.05 and false negative at p=0.1. Sex ratio changes represent outcomes relatively easily detected. Proposed application of these criteria to Negev populations and an example of such applications to published work place exposures to dioxins are shown.

School progress and cognitive development of 6-year-old children whose mothers were treated antenatally with betamethasone

The cognitive development of children whose mothers had been included in the first Auckland trials of betamethasone therapy in premature labor were studied. An earlier study of these children used psychometric tests during the fifth year of life. In the present study tests were given during the seventh year of life (the second year of school) to 250 (82.2%) of 304 surviving children. Of the 250 children, 139 were in the group whose mothers had received betamethasone and 111 were in the control group. Further tests of cognitive development were made, together with assessment of the children's progress in school. Again, on the majority of measures there were no significant differences between children whose mothers had received betamethasone and the children in the control group. Calculations of statistical power showed that important differences were unlikely to have been missed.

Cognitive and psychosocial development of 4-year-old children whose mothers were treated antenatally with betamethasone

The present study was part of a larger study investigating the long-term development of children of mothers included in a controlled trial of betamethasone therapy in preterm labor, the purpose was to determine whether there are any benefits or hazards of treatment detectable up to the seventh year of life. The first 318 children of mothers included in the trial because of spontaneous premature labor were selected for study. Of 305 survivors, 258 (84.6%) were included in this phase of the study. Detailed tests of psychological development, together with assessments of psychosocial background, were made during the fifth year. Of the 258 children 144 were in the betamethasone group and 114 were control patients. Despite a heavy weighting of the betamethasone group with more prematurely delivered infants and more boys (resulting from improved perinatal survival of these children associated with betamethasone therapy), no significant differences emerged between the groups in measures of outcome. It was concluded that betamethasone therapy, under the conditions of the original trial, was not hazardous to cognitive development as measured in this study.

The effect of the Feingold diet on 'normal" school children

Approximately 300 children in seven primary (elementary) schools used the Feingold diet for two weeks. Ratings were made by teachers before and after use of the diet on questionnaires developed from Conners' long teacher questionnaire. The questionnaire incorporated Conners' hyperactivity factor items, but related to the normal or average child, by referring to most children. Of the total sample, 8.5% improved by five points or more. The mean before diet scores of children who improved were below the cut off value for hyperactivity, indicating hyperactivity itself is not a necessary condition for improvement. Item by item analysis of the response showed that the behavior problems mostly likely to show improvement were distractability, attention span, fiddling, and demands for attention. Parents provided information on the additive foods being ingested by their children. Those children who were reported to be taking a great deal of additive were found to rate significantly higher in behavioral problems compared with children receiving little additive.

ITPA and learning disability: a discriminant analysis

Two groups of children, (n = 144 and n = 49), identified as different on measures of reading and spelling were found to exhibit different performance levels on the Illinois Test of Psycholinguistic Abilities (ITPA). Seven discriminant analyses were performed with significant group separation occurring for six of these. Classification analyses indicated that using the ten major subtests produced accurate classification in approximately 71% of cases. Subtests found to load heavily in discriminant functions were Auditory Sequential Memory and Auditory Reception. Other subtests, which loaded moderately, were Auditory Association, Visual Association, Verbal Expression, and Grammatic Closure. Results were discussed in the light of previous research methodologies and the debate as to the educational relevance of the ITPA.