Dressing Cosets

The account of the Poisson-Lie T-duality is presented for the case when the action of the duality group on a target is not free. At the same time a generalization of the picture is given when the duality group does not even act on \si-model targets but only on their phase spaces. The outcome is a huge class of dualizable targets generically having no local isometries or Poisson-Lie symmetries whatsoever.Comment: 11 pages, LaTe

Open Strings and D-branes in WZNW model

An abundance of the Poisson-Lie symmetries of the WZNW models is uncovered. They give rise, via the Poisson-Lie $T$-duality, to a rich structure of the dual pairs of $D$-branes configurations in group manifolds. The $D$-branes are characterized by their shapes and certain two-forms living on them. The WZNW path integral for the interacting $D$-branes diagrams is unambiguously defined if the two-form on the $D$-brane and the WZNW three-form on the group form an integer-valued cocycle in the relative singular cohomology of the group manifold with respect to its $D$-brane submanifold. An example of the $SU(N)$ WZNW model is studied in some detail.Comment: 28 pages, LaTe

Poisson-Lie T-duality: Open Strings and D-branes

Global issues of the Poisson-Lie T-duality are addressed. It is shown that oriented open strings propagating on a group manifold $G$ are dual to $D$-brane - anti-$D$-brane pairs propagating on the dual group manifold \ti G. The $D$-branes coincide with the symplectic leaves of the standard Poisson structure induced on the dual group \ti G by the dressing action of the group $G$. T-duality maps the momentum of the open string into the mutual distance of the $D$-branes in the pair. The whole picture is then extended to the full modular space $M(D)$ of the Poisson-Lie equivalent \si-models which is the space of all Manin triples of a given Drinfeld double.T-duality rotates the zero modes of pairs of $D$-branes living on targets belonging to $M(D)$. In this more general case the $D$-branes are preimages of symplectic leaves in certain Poisson homogeneous spaces of their targets and, as such, they are either all even or all odd dimensional.Comment: 15 pages, LaTeX (references added

In Vitro Biocompatibility of Several Children's Toothpastes on Human Gingival Fibroblasts

The European Academy of Paediatric Dentistry has recommended fluoride toothpastes from the eruption of the first teeth in children. Toothpastes stay in the mouth in contact with human gingival fibroblasts (hGFs) for a long time. Thus, the objective of this study was to compare the cytotoxicity of five different commonly used children's toothpastes: Oral B Kids +3 (Procter & Gamble, Alicante, Spain), Fluor Kin Calcium (Kin, Madrid, Spain), PHB Junior (PHB, Barcelona, Spain), Colgate +3 (Colgate Palmolive, Madrid, Spain) and Vitis Kids (Dentaid, Valencia, Spain) on hGFs. The children's toothpastes were exposed to hGFs at different concentrations (1:1, 1:2, 1:4). Afterwards, several tests were performed: MTT assays, cell cycle analyses, cell cytoskeleton staining assays, apoptosis/necrosis assays, and ICP-MS and ion chromatography. Oral B displayed the lowest cytotoxicity and was the toothpaste with the highest fluoride ion release; meanwhile, the other toothpastes were cytotoxic (*** p < 0.0001); Fluor Kin being the one with the lowest fluoride ion release. Among all the toothpastes analyzed, Oral B exhibited the best results in vitro in terms of biocompatibility. Future evaluations, both in vitro and in vivo, are required to confirm the biocompatibility of sodium lauryl sarcosinate and sodium lauryl sulfate containing toothpastes

Search of dark-matter axions in the microwave frequency range with full-wave modal techniques

Axions, originally proposed to solve the strong Charge-Parity problem of Quantum Chromo-Dynamics theory, emerge now as leading candidates of dark matter. In fact, the search of dark-matter axions in the microwave frequency range has been developed by different research groups during the last twenty years. In this demanding scenario, several microwave passive components (haloscopes) have been designed and fabricated for such axions detection based on the use of cavities and multi-cavities. From an electromagnetic point of view, comercial software (ANSFT HFSS, CST MICROWAVE STUDIO, etc ) has been employed for the design of different kind of haloscopes. In this work we propose to use the BI-RME 3D method (Boundary Integral – Resonant Mode Expansion) as an alternative to analyze the axion-photon coupling existing within an haloscope. This full-wave modal technique has provided interesting wide-band results for the design of new haloscopes

Effect of polymer structure on gas transport properties of selected aromatic polyimides, polyamides and TR polymers

Thermally rearranged (TR) polymers are formed through a thermally induced solid-state reaction of polyimides or polyamides that contain nucleophilic reactive groups ortho-positioned to their diamine. Naturally, the transport properties of TR polymers are intimately related to the chemical structure and reactivity of their precursors. Herein, we report characterization and transport properties for three poly(hydroxyimide) precursors prepared via thermal imidization in solution and for their corresponding TR polymers. Structural modifications to the polymer backbone can be used to control thermal rearrangement reaction kinetics. In regards to TR polymer formation, samples prepared from diamines with biphenyl functionality reacted more efficiently than those prepared from diamines with hexafluoroisopropylidene-linked aromatic units. However, hexafluoroisopropylidene functional units provided the highest combinations of permeability and selectivity for separations involving H2, N2, O2, CH4, and CO2. Differences in permeability between samples correlated well with changes in free volume, and 3 poly(hydroxyimide)s showed unusually high selectivities for their given free volume. The effect of synthesis route was also investigated for a specific TR polymer derived from 3,3'-dihydroxy-4,4'-diamino-biphenyl (HAB) and 2,2'-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA). Poly(hydroxyimide) precursors prepared via thermal imidization in solution and thermal imidization in the solid-state showed nearly identical permeabilities and selectivities regardless of synthesis route. However, after thermal rearrangement, the TR polymers prepared from polyimides synthesized via solid-state imidization have higher gas permeabilities than their solution-imidized analogs. In addition to light gas permeabilities, plasticization effects were investigated with CO2 hysteresis loops for all samples, and pure-gas olefin/paraffin permeabilities were determined for a TR polymer derived from 2,2-bis(3-amino-4-hydroxyphenyl)-hexafluoropropane (APAF) and 6FDA. With the exception of HAB-6FDA polyimides, pure-gas CO2 feed pressures up to approximately 50bar do not reveal a plasticization pressure point, but conditioning effects are observed for most samples. APAF-6FDA TR polymers have pure-gas permeabilities and selectivities beyond the propylene/propane upper bound.The authors gratefully acknowledge the support from Grant DE-FG02-02ER15362,whichwasadministeredbytheU.S.De-partment of Energy(DOE), Division of Chemical Sciences, Geos-ciences, and Biosciences through the Office of Basic Energy Sciences. Additionally, the authors gratefully acknowledge support from the DOEO ffice of Science Graduate Fellowship Program, which managed under DOE contract number DE-AC05-06OR23100 by Oak Ridge Associated Universities (ORAU) and adinistered by the Oak Ridge Institute for Science and Education (ORISE).Peer Reviewe

Solid pseudopapillary tumor of the pancreas (SPPT). Still an unsolved enigma

Solid pseudo-papillary tumor (SPPT) is a rare cystic tumor of the pancreas (1-3% of exocrine tumors of the pancreas) which shows an “enigmatic” behavior on the clinical and molecular pattern. A retrospective analysis of the citological studies and resected specimens of pancreatic cystic tumors from May 1996 to February 2010 was carried out. Three cases of SPPT were found, which are the objective of this study. The diagnosis was established upon occasional finding in the abdominal CT, in spite of sizing between 3 and 6 cm of diameter. In the three cases the preoperative diagnosis was confirmed by citology and specific immunohistochemical staining. Cases 2 and 3 showed strong immunoreactivity for Beta-Catenina and E-Cadherina staining. Radical resection (R0) was carried out in the three cases. A young male –21 years of age (case 1)- who had duodenal infiltration and two lymph nodes metastases died of hepatic and peritoneal recurrence 20 months following surgery. The other two cases are free of disease. The current review of the literature reports roughly 800 cases since the first report in 1959, and shows the enigmatic character of this tumor regarding the cellular origin, molecular pathways, prognostic factors and clinical behavior

Intraductal papillary mucinous neoplasms (IPMN) of the pancreas: clinico-pathologic results

Background: intraductal papillary mucinous neoplasm (IPMN) shows a series of lesions which evolve from benign lesions –adenoma– to invasive carcinoma. Aim: to analyze the clinical and pathological results of 15 patients diagnosed of IPMN, and surgically treated according to the guidelines of International Consensus Conference. Material and methods: a retrospective analysis of 15 patients surgically treated between March 1993 and September 2009, according to the International Consensus recommendation. Demographic, diagnostic tools, surgical report, pathologic database and actuarial survival were analyzed with a follow-up from one and a half month through nine years. Results: 6 patients underwent pancreaticoduodenectomies, 4 total pancreatectomies, 2 body or central pancreatectomies, 2 partial pancreatectomies (enucleation) and 1 distal pancreatectomy. A morbidity of 46 and 0% hospital mortality were assessed, with a median length hospital stay of 10 days. In five cases, the IPMN was combined type (both main and branch pancreatic ducts involved) in four main duct-type and branch duct-type in the another six as well. Several atypia (IPMN carcinoma in situ) was observed in 2 patients and invasive carcinoma with negative lymph nodes was identified in 3 patients. A patient without invasive carcinoma died at 66 months of follow-up for pancreas adenocarcinoma. The actuarial survival up to recurrence or death was 105,133 months with a range of follow-up from 1 month and a half until 9 years. Conclusions: IPMN main duct or mixed type warrants complete resection due to its incidence of invasive carcinoma or precursor lesions of malignancy as well. Due to its multifocal pattern, patients should be followed in long-term surveillance. The management of asymptomatic IPMN type branch less than 3 cm is controversial