234 research outputs found
Fabrication of Resorcinol-Formaldehyde Xerogel based High Aspect Ratio 3-D Hierarchical C-MEMS Structures
We demonstrate a novel method to fabricate arrays of resorcinol-
formaldehyde xerogel (RFX) based high aspect ratio (HAR) three-
dimensional (3-D) hierarchical C-MEMS structures. Starting from
a master pattern of HAR 3-D posts fabricated in SU-8 negative
photoresist by photolithography, a negative PDMS stamp with
arrays of holes was prepared by micromolding. The PDMS stamp
was then used to fabricate HAR 3-D RFX posts by replica molding.
The 3-D RFX posts thus fabricated were electrosprayed with SU-8
or an RF sol in the form of submicron or nano sized droplets and
followed by pyrolysis to yield HAR 3-D hierarchical carbon posts.
To characterize their use in C-MEMS based batteries,
galvanostatic (charge and discharge) experiments on RFX derived
carbon showed that it can be reversibly intercalated with Li ions
and possesses superior intercalation properties as compared to SU-
8 derived carbon which is a widely used material in C-MEMS
La punción aspiración con aguja fina (PAAF) en el diagnóstico de actinomicosis cervicofacial: estudio de 15 casos
Objetivos:
La actinomicosis es una enfermedad infecciosa muy poco frecuente
en nuestros días, a pesar de lo cual, su diagnóstico debe
ser tenido en cuenta por el clínico que se enfrenta a una lesión
persistente a nivel cervicofacial.
Aún tratándose de una enfermedad infecciosa, los cultivos microbiológicos
son pocas veces diagnósticos, por lo que el estudio
histopatológico y las pruebas de imagen son esenciales.
Nuestro interés es exponer nuestra experiencia en el manejo de
la actinomicosis de localización cervicofacial, su presentación
clínica, evolución y tratamiento, siempre apoyados en la que
creemos que es su técnica diagnóstica de elección, la PAAF.
Diseño del estudio:
A lo largo de 16 años se han diagnosticado 15 pacientes de
actinomicosis cervicofacial mediante PAAF, siendo estudiados
y tratados por los Servicios de Cirugía Maxilofacial, Medicina
Interna y Pediatría del Hospital Universitari de Girona Doctor
Josep Trueta.
La clínica, la evolución, la localización de las lesiones, cultivo
y el tratamiento con antibioticoterapia de duración prolongada,
asociado en algunos casos a intervención quirúrgica, son datos
valorados en nuestro estudio.
Resultados y conclusiones:
El estudio anatomopatológico mediante la punción aspiración con
aguja fina (PAAF), es un método sencillo, rápido y seguro, de una
alta sensibilidad diagnóstica, puesto que nos ha permitido el diagnóstico
definitivo de los 15 casos seguidos en nuestro Hospital.
La evolución clínica fue favorable en todos los pacientes, con
un único caso de recidiva clínica, solucionado con un segundo
tratamiento.
El tratamiento instaurado fue curativo en todos los casos.Objectives:
Actinomycosis is quite an infrequent bacterial infection nowadays.
However it can be considered in cases with a persistent cervicofacial
disease.
Although it is a bacterial infection, microbiologic cultures are
frequently not diagnoses, therefore histopathologic studies and
image studies are essential.
Our interest is to explain our experience with cervicofacial actinomycosis;
the clinical behaviour, evolution and treatment, always
assisted by their elected diagnostic technique: the FNAC.
Study design:
In the last 16 years, 15 patients have been diagnosed with cervicofacial
actinomycosis by FNAC, treated by Maxillofacial, Internal Medicine and Paediatrics units.
Clinical course, evolution, anatomical space situation, antibiotic
treatment, and surgical treatment have been studied.
Results and conclusions:
The fine-needle aspiration cytology (FNAC) is an easy, safe
and rapid method, with a high effect, that has made the final
diagnosis in 15 cases in our Hospital.
All the patients have had a good clinical evolution, only in one
case did we need a new treatment for recidive.
In all the cases treatment has been definitive.
Our interest is to explain our experience in the treatment of cervicofacial
actinomycosis, its clinical presentation and evolution,
together with its elected method of diagnosis, FNAC
Helicobacter pylori Dampens HLA-II Expression on Macrophages via the Up-Regulation of miRNAs Targeting CIITA
Macrophages have a major role in infectious and inflammatory diseases, and the available data suggest that Helicobacter pylori persistence can be explained in part by the failure of the bacterium to be killed by professional phagocytes. Macrophages are cells ready to kill the engulfed pathogen, through oxygen-dependent and -independent mechanisms; however, their killing potential can be further augmented by the intervention of T helper (Th) cells upon the specific recognition of human leukocyte antigen (HLA)-II\u2013peptide complexes on the surface of the phagocytic cells. As it pertains to H. pylori, the bacterium is engulfed by macrophages, but it interferes with the phagosome maturation process leading to phagosomes with an altered degradative capacity, and to megasomes, wherein H. pylori resists killing. We recently showed that macrophages infected with H. pylori strongly reduce the expression of HLA-II molecules on the plasma membrane and this compromises the bacterial antigen presentation to Th lymphocytes. In this work, we demonstrate that H. pylori hampers HLA-II expression in macrophages, activated or non-activated by IFN-\u3b3, by down-regulating the expression of the class II major histocompatibility complex transactivator (CIITA), the \u201cmaster control factor\u201d for the expression of HLA class II genes. We provided evidence that this effect relies on the up-regulation of let-7f-5p, let-7i-5p, miR-146b-5p, and -185-5p targeting CIITA. MiRNA expression analysis performed on biopsies from H. pylori-infected patients confirmed the up-regulation of let-7i-5p, miR-146b-5p, and -185-5p in gastritis, in pre-invasive lesions, and in gastric cancer. Taken together, our results suggest that specific miRNAs may be directly involved in the H. pylori infection persistence and may contribute to confer the risk of developing gastric neoplasia in infected patients
A Reversible Phase Transition of 2D Coordination Layers by B–H∙∙∙Cu(II) Interactions in a Coordination Polymer
Materials that combine flexibility and open metal sites are crucial for myriad applications. In this article, we report a 2D coordination polymer (CP) assembled from CuII ions and a flexible meta-carborane-based linker [Cu2(L1)2(Solv)2]•xSolv (1-DMA, 1-DMF, and 1-MeOH; L1: 1,7-di(4-carboxyphenyl)-1,7-dicarba-closo-dodecaborane). 1-DMF undergoes an unusual example of reversible phase transition on solvent treatment (i.e., MeOH and CH2Cl2). Solvent exchange, followed by thermal activation provided a new porous phase that exhibits an estimated Brunauer-Emmett-Teller (BET) surface area of 301 m2 g−1 and is capable of a CO2 uptake of 41 cm3 g−1. The transformation is reversible and 1-DMF is reformed on addition of DMF to the porous phase. We provide evidence for the reversible process being the result of the formation/cleavage of weak but attractive B–H∙∙∙Cu interactions by a combination of single-crystal (SCXRD), powder (PXRD) X-ray diffraction, Raman spectroscopy, and DFT calculations.This research was funded by MEC grant CTQ2016-75150-R and the Generalitat de Catalunya
(2017/SGR/1720) and the Spanish MINECO through the Severo Ochoa Centers of Excellence Program, under
Grant SEV-2015-0496
Micro-fabrication of Carbon Structures by Pattern Miniaturization in Resorcinol-Formaldehyde Gel
A simple and novel method to fabricate and miniaturize surface and
sub-surface micro-structures and micro-patterns in glassy carbon is proposed
and demonstrated. An aqueous resorcinol-formaldehyde (RF) sol is employed for
micro-molding of the master-pattern to be replicated, followed by controlled
drying and pyrolysis of the gel to reproduce an isotropically shrunk replica in
carbon. The miniaturized version of the master-pattern thus replicated in
carbon is about one order of magnitude smaller than original master by
repeating three times the above cycle of molding and drying. The
micro-fabrication method proposed will greatly enhance the toolbox for a facile
fabrication of a variety of Carbon-MEMS and C-microfluidic devices.Comment: 16 pages, 5 figure
The class of the locus of intermediate Jacobians of cubic threefolds
We study the locus of intermediate Jacobians of cubic threefolds within the
moduli space of complex principally polarized abelian fivefolds, and its
generalization to arbitrary genus - the locus of abelian varieties with a
singular odd two-torsion point on the theta divisor. Assuming that this locus
has expected codimension (which we show to be true for genus up to 5), we
compute the class of this locus, and of is closure in the perfect cone toroidal
compactification, in the Chow, homology, and the tautological ring.
We work out the cases of genus up to 5 in detail, obtaining explicit
expressions for the classes of the closures of the locus of products of an
elliptic curve and a hyperelliptic genus 3 curve, in moduli of principally
polarized abelian fourfolds, and of the locus of intermediate Jacobians in
genus 5. In the course of our computation we also deal with various
intersections of boundary divisors of a level toroidal compactification, which
is of independent interest in understanding the cohomology and Chow rings of
the moduli spaces.Comment: v2: new section 9 on the geometry of the boundary of the locus of
intermediate Jacobians of cubic threefolds. Final version to appear in
Invent. Mat
Mechanism of biomolecular recognition of trimethyllysine by the fluorinated aromatic cage of KDM5A PHD3 finger
The understanding of biomolecular recognition of posttranslationally modified histone proteins is centrally important to the histone code hypothesis. Despite extensive binding and structural studies on the readout of histones, the molecular language by which posttranslational modifications on histone proteins are read remains poorly understood. Here we report physical-organic chemistry studies on the recognition of the positively charged trimethyllysine by the electron-rich aromatic cage containing PHD3 finger of KDM5A. The aromatic character of two tryptophan residues that solely constitute the aromatic cage of KDM5A was fine-tuned by the incorporation of fluorine substituents. Our thermodynamic analyses reveal that the wild-type and fluorinated KDM5A PHD3 fingers associate equally well with trimethyllysine. This work demonstrates that the biomolecular recognition of trimethyllysine by fluorinated aromatic cages is associated with weaker cation-π interactions that are compensated by the energetically more favourable trimethyllysine-mediated release of high-energy water molecules that occupy the aromatic cage
Cobaltabis(dicarbollide) ([o-COSAN]−) as Multifunctional Chemotherapeutics: A Prospective Application in Boron Neutron Capture Therapy (BNCT) for Glioblastoma
Purpose: The aim of our study was to assess if the sodium salt of cobaltabis(dicarbollide) and its di-iodinated derivative (Na[o-COSAN] and Na[8,8′-I2-o-COSAN]) could be promising agents for dual anti-cancer treatment (chemotherapy + BNCT) for GBM. Methods: The biological activities of the small molecules were evaluated in vitro with glioblastoma cells lines U87 and T98G in 2D and 3D cell models and in vivo in the small model animal Caenorhabditis elegans (C. elegans) at the L4-stage and using the eggs. Results: Our studies indicated that only spheroids from the U87 cell line have impaired growth after treatment with both compounds, suggesting an increased resistance from T98G spheroids, contrary to what was observed in the monolayer culture, which highlights the need to employ 3D models for future GBM studies. In vitro tests in U87 and T98G cells conclude that the amount of 10B inside the cells is enough for BNCT irradiation. BNCT becomes more effective on T98G after their incubation with Na[8,8′-I2-o-COSAN], whereas no apparent cell-killing effect was observed for untreated cells. Conclusions: These small molecules, particularly [8,8′-I2-o-COSAN]−, are serious candidates for BNCT now that the facilities of accelerator-based neutron sources are more accessible, providing an alternative treatment for resistant glioblastoma
Management of Low-Grade Glioma
The optimal management of patients with low-grade glioma (LGG) is controversial. The controversy largely stems from the lack of well-designed clinical trials with adequate follow-up to account for the relatively long progression-free survival and overall survival of patients with LGG. Nonetheless, the literature increasingly suggests that expectant management is no longer optimal. Rather, there is mounting evidence supporting active management including consideration of surgical resection, radiotherapy, chemotherapy, molecular and histopathologic characterization, and use of modern imaging techniques for monitoring and prognostication. In particular, there is growing evidence favoring extensive surgical resection and increasing interest in the role of chemotherapy (especially temozolomide) in the management of these tumors. In this review, we critically analyze emerging trends in the literature with respect to management of LGG, with particular emphasis on reports published during the past year
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