380 research outputs found
Infinite-dimensional representations of the rotation group and Dirac's monopole problem
Within the context of infinite-dimensional representations of the rotation
group the Dirac monopole problem is studied in details. Irreducible
infinite-dimensional representations, being realized in the indefinite metric
Hilbert space, are given by linear unbounded operators in infinite-dimensional
topological spaces, supplied with a weak topology and associated weak
convergence. We argue that an arbitrary magnetic charge is allowed, and the
Dirac quantization condition can be replaced by a generalized quantization rule
yielding a new quantum number, the so-called topological spin, which is related
to the weight of the Dirac string.Comment: JHEP style. Extended version of hep-th/0403146. Revised version,
title and some notations are changed. References and Appendix B are adde
Evaluation of the response to treatment and clinical evolution in patients with burning mouth syndrome
Objective: the aim of this study is to investigate the clinical evolution, the spontaneous remission of the symptomatology and the response to different treatments in a group of burning mouth syndrome patients.
Study Design: the sample was formed by a group of patients that were visited in the Unit of Oral Medicine of the
Dentistry Clinic of the University of Barcelona, from the year 2000 to 2011. After revising the clinical records
of all the patients that had been under control for a period of time of 18 months or longer, they were contacted by
telephone. In the telephone interview, they were questioned about the symptomatology evolution and the response
to the treatments received, noting down the data in a questionnaire previously performed.
Results: the average duration of the symptoms was 6.5 years (+/-2.5 years). The most frequent treatments were:
chlorhexidine mouthrinses, oral benzodiazepines, topical clonazepam, antiinflamatory drugs, antidepressants,
antifungicals, vitamins, psycotherapy, salivary substitutes and topical corticoids. The specialists that were consulted with a higher frequency were: dermatologists (30%), othorrynolaringologists (10%) and psychiatrists (3%).
In 41 patients the oral symptoms did not improve, 35 reported partial improvements, 12 patients worsened, and
only in 3 patients the symptoms remitted.
Conclusions: In three of the 91 patients studied the symptoms remitted spontaneously within the five years of
treatment. Only 42% of the study population had improved the symptomatology significantly, and this improvement would reach 60% if clonazepam were associated to psychotherapy
Vector-valued operators, optimal weighted estimates and the condition
In this paper some new results concerning the classes introduced by Muckenhoupt and later extended by Sawyer, are provided. In particular we extend the result to the full range expected , to the weak norm, to other operators and to their vector-valued extensions. Some of those results rely upon sparse domination results that in some cases we provide as well. We will also provide sharp weighted estimates for vector valued extensions relying on those sparse domination results.UNLP 11/X752 and PICT 2014-1771 ANPCYT, Argentina.
Juan de la Cierva - Formaci\'on 2015 FJCI-2015-24547.
CONICET PIP 11220130100329CO, Argentina
Esclerosis tuberosa y manifestaciones orales: caso clínico
La esclerosis tuberosa (ET) es una anomalía congénita del desarrollo
embrionario que se transmite de forma autosómica
dominante y tiene diferentes formas de expresión clínica. Se
clasifica dentro de las denominadas facomatosis (phakos 'mancha'
y oma 'tumor'), que son anomalías del desarrollo, susceptibles
de originar tumores y/o hamartomas del sistema nervioso.
Es importante destacar que las lesiones del sistema nervioso
se acompañan, prácticamente siempre, de anomalías cutáneas.
En este trabajo presentamos el caso de una paciente de
55 años de edad, diagnosticada desde hace años de esclerosis
tuberosa, que cursa con lesiones intraorales compatibles
clínicamente con fibromas. Estas lesiones de aspecto
fibromatoso se presentan sobre todo en el labio inferior y en
ambas mucosas yugales, localización poco referenciada para
esta manifestación en la enfermedad de base que nos ocupa. La
anatomía patológica sugiere lesiones compatibles con
angiomiolipoma.
También repasamos los datos referentes a la ET, se describen
las implicaciones orales de la misma y en base al resultado
histopatológico obtenido se revisa el significado del término
angiomiolipoma.Tuberous sclerosis (TS) is a congenital anomaly in the
development of the embryo which is transmitted through the
autosomal dominant gene. It has various forms of clinical
expression. It is classified as one of what are known as
Phacomatoses (phakos stain and oma tumour), which are
development anomalies that can originate tumours and/or
hamartomas in the nervous system. Lesions in the nervous
system are nearly always accompanied by cutaneous anomalies.
In this study we introduce the case of a woman patient aged 55,
diagnosed several years earlier with Tuberous Sclerosis, who
attended for intraoral lesions which were clinically compatible
with fibromata. These lesions of fibrous appearance occurred
above all on the lower lip and in both cheeks' mucous membranes,
little mentioned in the literature as a site for such a
manifestation of TS. The pathological anatomy suggested
lesions compatible with Angiomyolipoma.
In addition, the data referring to TS are reviewed; its implications
for the mouth are described; and histopathological results are
used to examine the significance of the word Angiomyolipoma
Magnetotransport in two-dimensional electron gas at large filling factors
We derive the quantum Boltzmann equation for the two-dimensional electron gas
in a magnetic field such that the filling factor . This equation
describes all of the effects of the external fields on the impurity collision
integral including Shubnikov-de Haas oscillations, smooth part of the
magnetoresistance, and non-linear transport. Furthemore, we obtain quantitative
results for the effect of the external microwave radiation on the linear and
non-linear transport in the system. Our findings are relevant for the
description of the oscillating resistivity discovered by Zudov {\em et al.},
zero-resistance state discovered by Mani {\em et al.} and Zudov {\em et al.},
and for the microscopic justification of the model of Andreev {\em et al.}. We
also present semiclassical picture for the qualitative consideration of the
effects of the applied field on the collision integral.Comment: 28 pages, 19 figures; The discussion of the role of the effect of the
microwave field on the distribution function is revised (see also
cond-mat/0310668). Accepted in Phys. Rev.
PHF6 regulates phenotypic plasticity through chromatin organization within lineage-specific genes
Developmental and lineage plasticity have been observed in numerous malignancies and have been correlated with tumor progression and drug resistance. However, little is known about the molecular mechanisms that enable such plasticity to occur. Here, we describe the function of the plant homeodomain finger protein 6 (PHF6) in leukemia and define its role in regulating chromatin accessibility to lineage-specific transcription factors. We show that loss of Phf6 in B-cell leukemia results in systematic changes in gene expression via alteration of the chromatin landscape at the transcriptional start sites of B-cell- and T-cell-specific factors. Additionally, Phf6KO cells show significant down-regulation of genes involved in the development and function of normal B cells, show up-regulation of genes involved in T-cell signaling, and give rise to mixed-lineage lymphoma in vivo. Engagement of divergent transcriptional programs results in phenotypic plasticity that leads to altered disease presentation in vivo, tolerance of aberrant oncogenic signaling, and differential sensitivity to frontline and targeted therapies. These findings suggest that active maintenance of a precise chromatin landscape is essential for sustaining proper leukemia cell identity and that loss of a single factor (PHF6) can cause focal changes in chromatin accessibility and nucleosome positioning that render cells susceptible to lineage transition.National Cancer Institute ; F31-CA183405 - National Institutes of Health ; 1122374 - National Science Foundation ; Ludwig Center for Molecular Oncology at Massachusetts Institute of Technology ; Koch Institute ; Dana-Farber/Harvard Cancer Center ; P30-CA14051 - Koch Institute ; NCI ; NIH ; National Science Foundatio
Antarctic ice sheet discharge driven by atmosphere-ocean feedbacks at the Last Glacial Termination
Reconstructing the dynamic response of the Antarctic ice sheets to warming during the Last Glacial Termination (LGT; 18,000–11,650 yrs ago) allows us to disentangle ice-climate feedbacks that are key to improving future projections. Whilst the sequence of events during this period is reasonably well-known, relatively poor chronological control has precluded precise alignment of ice, atmospheric and marine records, making it difficult to assess relationships between Antarctic ice-sheet (AIS) dynamics, climate change and sea level. Here we present results from a highly-resolved ‘horizontal ice core’ from the Weddell Sea Embayment, which records millennial-scale AIS dynamics across this extensive region. Counterintuitively, we find AIS mass-loss across the full duration of the Antarctic Cold Reversal (ACR; 14,600–12,700 yrs ago), with stabilisation during the subsequent millennia of atmospheric warming. Earth-system and ice-sheet modelling suggests these contrasting trends were likely Antarctic-wide, sustained by feedbacks amplified by the delivery of Circumpolar Deep Water onto the continental shelf. Given the anti-phase relationship between inter-hemispheric climate trends across the LGT our findings demonstrate that Southern Ocean-AIS feedbacks were controlled by global atmospheric teleconnections. With increasing stratification of the Southern Ocean and intensification of mid-latitude westerly winds today, such teleconnections could amplify AIS mass loss and accelerate global sea-level rise
The chromatin landscape of primary synovial sarcoma organoids is linked to specific epigenetic mechanisms and dependencies.
Synovial sarcoma (SyS) is an aggressive mesenchymal malignancy invariably associated with the chromosomal translocation t(X:18; p11:q11), which results in the in-frame fusion of the BAF complex gene SS18 to one of three SSX genes. Fusion of SS18 to SSX generates an aberrant transcriptional regulator, which, in permissive cells, drives tumor development by initiating major chromatin remodeling events that disrupt the balance between BAF-mediated gene activation and polycomb-dependent repression. Here, we developed SyS organoids and performed genome-wide epigenomic profiling of these models and mesenchymal precursors to define SyS-specific chromatin remodeling mechanisms and dependencies. We show that SS18-SSX induces broad BAF domains at its binding sites, which oppose polycomb repressor complex (PRC) 2 activity, while facilitating recruitment of a non-canonical (nc)PRC1 variant. Along with the uncoupling of polycomb complexes, we observed H3K27me3 eviction, H2AK119ub deposition and the establishment of de novo active regulatory elements that drive SyS identity. These alterations are completely reversible upon SS18-SSX depletion and are associated with vulnerability to USP7 loss, a core member of ncPRC1.1. Using the power of primary tumor organoids, our work helps define the mechanisms of epigenetic dysregulation on which SyS cells are dependent
Drug release properties of diflunisal from layer-by-layer self-assembled kappa-carrageenan/chitosan nanocapsules: effect of deposited layers
Engineering of multifunctional drug nanocarriers combining stability and good release properties remains a great challenge. In this work, natural polymers kappa-carrageenan (kappa-CAR) and chitosan (CS) were deposited onto olive oil nanoemulsion droplets (NE) via layer-by-layer (LbL) self-assembly to study the release mechanisms of the anti-inflammatory diflunisal (DF) as a lipophilic drug model. The nano-systems were characterized by dynamic light scattering (DLS), zeta potential (zeta-potential) measurements, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (XEDS) and Fourier transform infrared spectroscopy (FTIR) to confirm the NE-coating with polymer layers. In addition, kinetic release studies of DF were developed by the dialysis diffusion bag technique. Mathematical models were applied to investigate the release mechanisms. The results showed that stable and suitably sized nanocapsules (similar to 300 nm) were formed. Also, the consecutive adsorption of polyelectrolytes by charge reversal was evidenced. More interestingly, the drug release mechanism varied depending on the number of layers deposited. The nanosized systems containing up to two layers showed anomalous transport and first order kinetics. Formulations with three and four layers exhibited Case II transport releasing diflunisal with zero order kinetics
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