Giant magnetic anisotropy at nanoscale: overcoming the superparamagnetic limit

It has been recently observed for palladium and gold nanoparticles, that the magnetic moment at constant applied field does not change with temperature over the range comprised between 5 and 300 K. These samples with size smaller than 2.5 nm exhibit remanence up to room temperature. The permanent magnetism for so small samples up to so high temperatures has been explained as due to blocking of local magnetic moment by giant magnetic anisotropies. In this report we show, by analysing the anisotropy of thiol capped gold films, that the orbital momentum induced at the surface conduction electrons is crucial to understand the observed giant anisotropy. The orbital motion is driven by localised charge and/or spin through spin orbit interaction, that reaches extremely high values at the surfaces. The induced orbital moment gives rise to an effective field of the order of 103 T that is responsible of the giant anisotropy.Comment: 15 pages, 2 figures, submitted to PR

Theory of Mind and Emotion Regulation Difficulties in Adolescents With Borderline Traits

Objective: Dysfunctions in both emotion regulation and social cognition (understanding behavior in mental state terms, theory of mind or mentalizing) have been proposed as explanations for disturbances of interpersonal behavior in borderline personality disorder (BPD). This study aimed to examine mentalizing in adolescents with emerging BPD from a dimensional and categorical point of view, controlling for gender, age, Axis I and Axis II symptoms, and to explore the mediating role of emotion regulation in the relation between theory of mind and borderline traits. Method: The newly developed Movie for the Assessment of Social Cognition (MASC) was administered alongside self-report measures of emotion regulation and psychopathology to 111 adolescent inpatients between the ages of 12 to 17 (mean age = 15.5 years; SD = 1.44 years). For categorical analyses borderline diagnosis was determined through semi-structured clinical interview, which showed that 23% of the sample met criteria for BPD. Results: Findings suggest a relationship between borderline traits and "hypermentalizing" (excessive, inaccurate mentalizing) independent of age, gender, externalizing, internalizing and psychopathy symptoms. The relation between hypermentalizing and BPD traits was partially mediated by difficulties in emotion regulation, accounting for 43.5% of the hypermentalizing to BPD path. Conclusions: Results suggest that in adolescents with borderline personality features the loss of mentalization is more apparent in the emergence of unusual alternative strategies (hypermentalizing) than in the loss of the capacity per se (no mentalizing or undermentalizing). Moreover, for the first time, empirical evidence is provided to support the notion that mentalizing exerts its influence on borderline traits through the mediating role of emotion dysregulation. J. Am. Acad. Child Adolesc. Psychiatry, 2011;50(6): 563-573

Surface plasmon resonance of capped Au nanoparticles

In this Rapid Communication we show the relationship between surface plasmon resonance damping and the intensity of surface bonding for capped Au nanoparticles, (NPs). Up to now the influence of capping has been included as a phenomenological modification of the scattering constant. It is indicated here that the effective NP size is the parameter mainly affected by surface bonding. Experimental results in different Au-thiol NPs are shown to be in excellent agreement with the expression we propose for damping. Moreover, according to our model the resonance profile gives a deep insight of the interface bonding strength

Expression of carbonic anhydrase II (CA II) promoter-reporter fusion genes in multiple tissues of transgenic mice does not replicate normal patterns of expression indicating complexity of CA II regulation in vivo

Although the proximal, 5′ 115 bp of the human carbonic anhydrase II (CA II) gene was sufficient for expression of a reporter gene in some transfected cell lines, we found previously that 1100 bp of this promoter (or 500 bp of the mouse CA II promoter) was not sufficient for expression in transgenic mice. We have now studied the expression of linked reporter genes in mice transgenic for either (1) 11 kb of the human 5′ promoter or (2) 8 kb of the human 5′ promoter with mouse sequences from the first exon, part of the first intron (since a CpG island spans this region), and the 3′ sequences of the gene. Expression was found in both cases, but the tissue specificity was not appropriate for CA II. Although there was a difference in the sensitivity of the assays used, the first construct led to expression in many tissues, while the second construct was expressed only in spleen. These findings indicate considerable complexity of DNA control regions for in vivo CA II expression.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44160/1/10528_2004_Article_BF00554600.pd

From START to FINISH : the influence of osmotic stress on the cell cycle

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DNA polymorphism in the 5′ flanking region of the human carbonic anhydrase II gene on chromosome 8

A restriction-fragment-length polymorphism (RFLP) is described which is associated with the human carbonic anhydrase II gene ( CA2 ) that codes for one of the three genetically distinct carbonic anhydrase isozymes, CA I, CA II, and CA III. The isolated DNA was cleaved with several restriction enzymes and subjected to Southern blot hybridization analysis using a DNA probe containing the 5′ end of the human CA II gene. A two allele RFLP which was detected with the restriction endonuclease, Taq I, is expressed phenotypically on Southern blots as either a 5.4 kilobase (kb) fragment or as 4.0 and 1.4 kb fragments. These fragments result from the presence or absence of a Taq I recognition site in the 5′ flanking region approximately 1.0kb from the initiation codon of the CA II gene. Segregation analysis showed that the alleles are inherited in a Mendelian fashion, with a frequency of 50%.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47613/1/439_2004_Article_BF00291652.pd