Electron-hole pair condensation at the semimetal-semiconductor transition: a BCS-BEC crossover scenario

We act on the suggestion that an excitonic insulator state might separate---at very low temperatures---a semimetal from a semiconductor and ask for the nature of these transitions. Based on the analysis of electron-hole pairing in the extended Falicov-Kimball model, we show that tuning the Coulomb attraction between both species, a continuous crossover between a BCS-like transition of Cooper-type pairs and a Bose-Einstein condensation of preformed tightly-bound excitons might be achieved in a solid-state system. The precursor of this crossover in the normal state might cause the transport anomalies observed in several strongly correlated mixed-valence compounds.Comment: 5 pages, 5 figures, substantially revised versio

Oral HRAS Mutation in Orofacial Nevus Sebaceous Syndrome (Schimmelpenning-Feuerstein-Mims-Syndrome): A Case Report With a Literature Survey

Background/Aim: The aim of this study was to present the long-term course of a patient with nevus sebaceous syndrome (NSS). Recent genetic studies place the syndrome in the emerging group of so-called RASopathies. The focus of the report is on surgical treatment and morphological and genetic findings of the face and oral cavity. Case Report: A female patient was treated for congenital alterations of facial skin and oral mucosa. The oral lesions were removed repeatedly. Eruption of teeth on the lesion sites was made easier by the measures taken. However, after repeated ablation of the affected gingiva, the periodontal papillomatous epithelium re-differentiated into the same reddish, conspicuous, hyperplastic epithelium. The teeth in the affected region showed noticeable changes in position, surface, and shape. A HRAS mutation was detected only in the regions of altered oral epithelia and not in adjacent soft tissues. Conclusion: Reports on NSS rarely address oral manifestations. The recorded alterations of oral soft and hard tissues in NSS indicate a topographical relationship between the development of oral mucosa and teeth as well as the long-lasting impact of a sporadic mutation on organ development at this site

A probabilistic analysis of argument cogency

This paper offers a probabilistic treatment of the conditions for argument cogency as endorsed in informal logic: acceptability, relevance, and sufficiency. Treating a natural language argument as a reason-claim-complex, our analysis identifies content features of defeasible argument on which the RSA conditions depend, namely: change in the commitment to the reason, the reason’s sensitivity and selectivity to the claim, one’s prior commitment to the claim, and the contextually determined thresholds of acceptability for reasons and for claims. Results contrast with, and may indeed serve to correct, the informal understanding and applications of the RSA criteria concerning their conceptual dependence, their function as update-thresholds, and their status as obligatory rather than permissive norms, but also show how these formal and informal normative approachs can in fact align

On the existence of the excitonic insulator phase in the extended Falicov-Kimball model: an SO(2)-invariant slave-boson approach

We re-examine the three-dimensional spinless Falicov-Kimball model with dispersive $f$ electrons at half-filling, addressing the dispute about the formation of an excitonic condensate, which is closely related to the problem of electronic ferroelectricity. To this end, we work out a slave-boson functional integral representation of the suchlike extended Falicov-Kimball model that preserves the $SO(2)\otimes U(1)^{\otimes 2}$ invariance of the action. We find a spontaneous pairing of $c$ electrons with $f$ holes, building an excitonic insulator state at low temperatures, also for the case of initially non-degenerate orbitals. This is in contrast to recent predictions of scalar slave-boson mean-field theory but corroborates previous Hartree-Fock and RPA results. Our more precise treatment of correlation effects, however, leads to a substantial reduction of the critical temperature. The different behavior of the partial densities of states in the weak and strong inter-orbital Coulomb interaction regimes supports a BCS-BEC transition scenario.Comment: slightly revised version, 10 pages, 6 figure

Linear response within the projection-based renormalization method: Many-body corrections beyond the random phase approximation

The explicit evaluation of linear response coefficients for interacting many-particle systems still poses a considerable challenge to theoreticians. In this work we use a novel many-particle renormalization technique, the so-called projector-based renormalization method, to show how such coefficients can systematically be evaluated. To demonstrate the prospects and power of our approach we consider the dynamical wave-vector dependent spin susceptibility of the two-dimensional Hubbard model and also determine the subsequent magnetic phase diagram close to half-filling. We show that the superior treatment of (Coulomb) correlation and fluctuation effects within the projector-based renormalization method significantly improves the standard random phase approximation results.Comment: 17 pages, 7 figures, revised versio

Endocrine Active UV Filters: Developmental Toxicity and Exposure Through Breast Milk

Several UV filters exhibit endocrine activity. Evidence for transdermal passage and presence in the food chain (fish) suggests potential exposure of humans during development. Developmental toxicity was studied in rats for the estrogenic UV filters 4-methylbenzylidene camphor (4-MBC, 0.7, 7, 24, 47 mg/kg/day) and 3-benzylidene camphor (3-BC, 0.07, 0.24, 0.7, 2.4, 7 mg/kg/day) administered in chow to the parent generation before mating, during pregnancy and lactation, and to the offspring until adulthood. Neonates exhibited enhanced prostate growth after 4-MBC and altered uterine gene expression after both filters. 4-MBC and 3-BC delayed male puberty and affected reproductive organ weights of adult offspring. Interactions with the thyroid were noted. Expression and estrogen sensitivity of target genes and nuclear receptor coregulators were altered at mRNA and protein levels in adult uterus, prostate and brain. Female sexual behavior was affected by 4-MBC and 3-BC, estrous cycles by 3-BC. Classical endpoints exhibited LOAELs/NOAELs of 7/0.7 mg/kg/day for 4-MBC and 0.24/0.07 mg/kg/day for 3-BC. Molecular endpoints were affected by the lowest doses. In order to obtain information on human exposure, we conducted a monitoring study on human milk with three series of mother–child pairs (2004, 2005, 2006), with focus on cosmetic UV filters in relation to other endocrine disrupters. Methods for UV filter analysis followed the principles of European standardized methods for pesticide residue analysis (EN 15289). In cohorts 2004 and 2005, 78.8% of women reported use of product(s) containing cosmetic UV filters in a questionnaire, and 76.5% of milk samples contained these filters. Use of UV filters and concentration in human milk were significantly correlated. The results agree with the idea of transdermal passage of UV filters. They also indicate that it may be possible to reduce human exposure during critical periods such as pregnancy and lactation by transiently abstaining from use

Focal segmental glomerulosclerosis, Coats’-like retinopathy, sensorineural deafness and chromosome 4 duplication: a new association

We describe the novel association in a girl of nephrotic syndrome due to focal segmental glomerulosclerosis, bilateral sensorineural deafness, basal ganglia calcification, bilateral retinopathy similar to that seen in Coats’ disease, with de novo duplication of a subtelomeric region of chromosome 4q35. The chromosomal duplication was identified during investigation of a possible association with features of fascio-scapulo-humeral dystrophy (FSHD). This duplication has not previously been reported with FSGS and adds to the expanding number of genetic associations with steroid-resistant nephrotic syndrome

The complex TIE between macrophages and angiogenesis

Macrophages are primarily known as phagocytic immune cells, but they also play a role in diverse processes, such as morphogenesis, homeostasis and regeneration. In this review, we discuss the influence of macrophages on angiogenesis, the process of new blood vessel formation from the pre-existing vasculature. Macrophages play crucial roles at each step of the angiogenic cascade, starting from new blood vessel sprouting to the remodelling of the vascular plexus and vessel maturation. Macrophages form promising targets for both pro- and anti-angiogenic treatments. However, to target macrophages, we will first need to understand the mechanisms that control the functional plasticity of macrophages during each of the steps of the angiogenic cascade. Here, we review recent insights in this topic. Special attention will be given to the TIE2-expressing macrophage (TEM), which is a subtype of highly angiogenic macrophages that is able to influence angiogenesis via the angiopoietin-TIE pathway

Activation of the Low Molecular Weight Protein Tyrosine Phosphatase in Keratinocytes Exposed to Hyperosmotic Stress

Herein, we provide new contribution to the mechanisms involved in keratinocytes response to hyperosmotic shock showing, for the first time, the participation of Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP) activity in this event. We reported that sorbitol-induced osmotic stress mediates alterations in the phosphorylation of pivotal cytoskeletal proteins, particularly Src and cofilin. Furthermore, an increase in the expression of the phosphorylated form of LMWPTP, which was followed by an augment in its catalytic activity, was observed. of particular importance, these responses occurred in an intracellular milieu characterized by elevated levels of reduced glutathione (GSH) and increased expression of the antioxidant enzymes glutathione peroxidase and glutathione reductase. Altogether, our results suggest that hyperosmostic stress provides a favorable cellular environment to the activation of LMWPTP, which is associated with increased expression of antioxidant enzymes, high levels of GSH and inhibition of Src kinase. Finally, the real contribution of LMWPTP in the hyperosmotic stress response of keratinocytes was demonstrated through analysis of the effects of ACP1 gene knockdown in stressed and non-stressed cells. LMWPTP knockdown attenuates the effects of sorbitol induced-stress in HaCaT cells, mainly in the status of Src kinase, Rac and STAT5 phosphorylation and activity. These results describe for the first time the participation of LMWPTP in the dynamics of cytoskeleton rearrangement during exposure of human keratinocytes to hyperosmotic shock, which may contribute to cell death.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Univ Estadual Campinas, Dept Bioquim, Inst Biol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Bioquim, São Paulo, SP, BrazilUniv Estadual Paulista, Dept Quim & Bioquim, IBB, São Paulo, BrazilUniv São Paulo, Dept Genet & Biol Evolut, São Paulo, SP, BrazilUniv Fed ABC, Ctr Ciencias Nat & Humanas, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Bioquim, São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, São Paulo, SP, BrazilFAPESP: 2006/07315-3CNPq: PQ-2Web of Scienc

Nineteen novel NPHS1 mutations in a worldwide cohort of patients with congenital nephrotic syndrome (CNS)

Background. Recessive mutations in the NPHS1 gene encoding nephrin account for ∼40% of infants with congenital nephrotic syndrome (CNS). CNS is defined as steroid-resistant nephrotic syndrome (SRNS) within the first 90 days of life. Currently, more than 119 different mutations of NPHS1 have been published affecting most exons. Methods. We here performed mutational analysis of NPHS1 in a worldwide cohort of 67 children from 62 different families with CNS. Results. We found bi-allelic mutations in 36 of the 62 families (58%) confirming in a worldwide cohort that about one-half of CNS is caused by NPHS1 mutations. In 26 families, mutations were homozygous, and in 10, they were compound heterozygous. In an additional nine patients from eight families, only one heterozygous mutation was detected. We detected 37 different mutations. Nineteen of the 37 were novel mutations (∼51.4%), including 11 missense mutations, 4 splice-site mutations, 3 nonsense mutations and 1 small deletion. In an additional patient with later manifestation, we discovered two further novel mutations, including the first one affecting a glycosylation site of nephrin. Conclusions. Our data hereby expand the spectrum of known mutations by 17.6%. Surprisingly, out of the two siblings with the homozygous novel mutation L587R in NPHS1, only one developed nephrotic syndrome before the age of 90 days, while the other one did not manifest until the age of 2 years. Both siblings also unexpectedly experienced an episode of partial remission upon steroid treatmen