130 research outputs found
Efficient Hybrid Continuous-Time/Discrete-Time ∑ Δ Modulators for Broadband Wireless Telecom Systems
This work analyzes the use of hybrid continous-time/discrete-time SD modulators for the implementation of analog-to-digital converters intended for wideband mobile applications. Two alternative multirate cascade SD architectures are discussed and analyzed, taking into account the impact of main circuit-level error mechanisms, namely: mismatch, finite dc gain and gain-bandwidth product. Both multirate cascade SD modulators in terms of their sensitivity to non-ideal effects, considering different target specifications. Theoretical predictions match simulation results, showing that the lowest performance degradation is obtained by a new king of multi-rate hybrid SD modulators, in which the continuous-time circuits operate at a higher rate than the discrete-time parts of the modulators.This work has been supported in part by the Spanish ministry of Science and Innovation (with support from the European Regional Development Fund) under contract TEC2010-14825/MIC, and in part by the regional Council of Innovation, Science and Enterprise under contract TIC-2532.Peer Reviewe
La interpretación geomorfológica en la cartografía de peligro de inundación
La interpretación geomorfológica de los procesos fluviales resulta fundamental para la elaboración de cartografía de peligro de inundación. Los ríos se comportan de una manera dinámica y pueden variar su topografía de una crecida a otra. Por ello, una cartografía de peligrosidad, excesivamente dependiente de modelos hidráulicos e hidrológicos, puede resultar ineficaz y quedarse obsoleta tras un suceso de alta energía. Conocer los elementos de geomorfología fluvial, así como sus procesos asociados permite una previsión a más largo plazo y una aproximación más realista al riesgo.
En este trabajo se presentan ejemplos de interpretación geomorfológica de formas y procesos fluviales, en clave de peligro de inundación. Se han seleccionado tres cuencas de diferentes entornos morfoclimáticos que, a distintas escalas, permiten ilustrar algunos puntos donde la geomorfología propicia un determinado proceso y, en consecuencia, condiciona el tipo de peligro de la zona. La interpretación geomorfológica se ha llevado a cabo mediante trabajo de campo, de laboratorio y a partir de imágenes de satélite (RADARSAT e Ikonos)
RUNX/AML and C/EBP factors regulate CD11a integrin expression in myeloid cells through overlapping regulatory elements
10 Figures. The publication costs of this article were defrayed in part by page charge
payment. Therefore, and solely to indicate this fact, this article is hereby
marked ‘‘advertisement’’ in accordance with 18 U.S.C. section 1734.The CD11a/CD18 (leukocyte function-associated antigen 1 [LFA-1]) integrin mediates critical leukocyte adhesive interactions during immune and inflammatory responses. The CD11a promoter directs CD11a/CD18 integrin expression, and its activity in lymphoid cells depends on a functional RUNX1/AML-1–binding site (AML-110) within the MS7 sequence. We now report that MS7 contains a C/EBP-binding site (C/EBP-100), which overlaps with AML-110 and is bound by C/EBP factors in myeloid cells. C/EBP and RUNX/AML factors compete for binding to their respective cognate elements and bind to the CD11a promoter MS7 sequence in a cell lineage- and differentiation-dependent manner. In myeloid cells MS7 is primarily recognized by C/EBP factors in proliferating cells whereas RUNX/AML factors (especially RUNX3/AML-2) bind to MS7 in differentiated cells. RUNX3/AML-2 binding to the CD11a promoter correlates with increased RUNX3/AML-2 protein levels and enhanced CD11a/CD18 cell surface expression. The relevance of the AML-110 element is underscored by the ability of AML-1/ETO to inhibit CD11a promoter activity, thus explaining the low CD11a/CD18 expression in t(8;21)–containing myeloid leukemia cells. Therefore, the expression of the CD11a/CD18 integrin in myeloid cells is determined through the differential occupancy of the CD11a proximal promoter by transcription factors implicated in the pathogenesis of myeloid leukemia.From the Centro de Investigaciones Biológicas, Consejo Superior de
Investigaciones Científicas, Madrid, Spain; Clínica Universitaria, Universidad de Navarra, Spain; Institute of Human Genetics, Aarhus, Denmark; Hospital Universitario Gregorio Maranón, Madrid, Spain; University of Colorado Health Sciences Center, Denver; and Department of Molecular Genetics, The
Weizmann Institute of Science, Rehovot Israel. Supported by grants 08.3/0026/2000.1 from Comunidad Auto´noma de Madrid,
01/0063-01 from Fondo de Investigaciones Sanitarias, and SAF2002-04615-
C02-01 from Ministerio de Ciencia y Tecnología (A.L.C.). We gratefully acknowledge Drs Ana Aranda and Aurora Sánchez-Pacheco for their very generous help with ChIP assays.Peer reviewe
Catastrophic expenditure due to out-of-pocket health payments and its determinants in Colombian households
Cold-Inducible RNA Binding Protein as a Vaccination Platform to Enhance Immunotherapeutic Responses against Hepatocellular Carcinoma
Therapies based on immune checkpoint inhibitors (ICPI) have yielded promising albeit
limited results in patients with hepatocellular carcinoma (HCC). Vaccines have been proposed as
combination partners to enhance response rates to ICPI. Thus, we analyzed the combined effect of a
vaccine based on the TLR4 ligand cold-inducible RNA binding protein (CIRP) plus ICPI. Mice were
immunized with vaccines containing ovalbumin linked to CIRP (OVA-CIRP), with or without ICPI,
and antigen-specific responses and therapeutic efficacy were tested in subcutaneous and orthotopic
mouse models of liver cancer. OVA-CIRP elicited polyepitopic T-cell responses, which were further
enhanced when combined with ICPI (anti-PD-1 and anti-CTLA-4). Combination of OVA-CIRP with
ICPI enhanced ICPI-induced therapeutic responses when tested in subcutaneous and intrahepatic
B16-OVA tumors, as well as in the orthotopic PM299L HCC model. This effect was associated
with higher OVA-specific T-cell responses in the periphery, although many tumor-infiltrating
lymphocytes still displayed an exhausted phenotype. Finally, a new vaccine containing human
glypican-3 linked to CIRP (GPC3-CIRP) induced clear responses in humanized HLA-A2.01 transgenic
mice, which increased upon combination with ICPI. Therefore, CIRP-based vaccines may generate anti-tumor immunity to enhance ICPI efficacy in HCC, although blockade of additional checkpoint
molecules and immunosuppressive targets should be also considered
RUNX/AML and C/EBP factors regulate CD11a integrin expression in myeloid cells through overlapping regulatory elements
The CD11a/CD18 (leukocyte functionassociated
antigen 1 [LFA-1]) integrin mediates
critical leukocyte adhesive interactions
during immune and inflammatory
responses. The CD11a promoter directs
CD11a/CD18 integrin expression, and its
activity in lymphoid cells depends on a
functional RUNX1/AML-1–binding site
(AML-110) within the MS7 sequence. We
now report that MS7 contains a C/EBPbinding
site (C/EBP-100), which overlaps
with AML-110 and is bound by C/EBP
factors in myeloid cells. C/EBP and RUNX/
AML factors compete for binding to their
respective cognate elements and bind to
the CD11a promoter MS7 sequence in a
cell lineage- and differentiation-dependent
manner. In myeloid cells MS7 is
primarily recognized by C/EBP factors in
proliferating cells whereas RUNX/AMLfactors
(especially RUNX3/AML-2) bind to
MS7 in differentiated cells. RUNX3/AML-2
binding to the CD11a promoter correlates
with increased RUNX3/AML-2 protein levels
and enhanced CD11a/CD18 cell surface
expression. The relevance of the
AML-110 element is underscored by the
ability of AML-1/ETO to inhibit CD11a promoter
activity, thus explaining the low
CD11a/CD18 expression in t(8;21)–containing
myeloid leukemia cells. Therefore,
the expression of the CD11a/CD18
integrin in myeloid cells is determined
through the differential occupancy of the
CD11a proximal promoter by transcription
factors implicated in the pathogenesis
of myeloid leukemia
Caracterización funcional de fibras comerciales modificadas por medios físicos.
A pesar de que los efectos benéficos de la fibra dietética a la salud humana son ampliamente reconocidos, y su deficiente consumo se asocia con numerosos padecimientos denominados “enfermedades de la civilización” (diabetes, obesidad, diverticulosis y afecciones cardiovasculares), también se ha observado que el aumento en el consumo de fibra dietética demostró tener efectos adversos en la digestión, absorción y utilización de la proteína y hierro de los alimentos. Por lo tanto, el propósito de la presente investigación será evaluar diferentes tratamientos físicos que ayuden a eficientizar la fortificación de los productos de panificación con fibra, permitiendo los efectos benéficos de esta en el organismo, pero sin que comprometa la calidad nutricia del producto final. De las diferentes pruebas funcionales se pudo observar que tanto el ultrasonido como las microondas causan modificaciones en las diferentes propiedades, esto se puede observar mayormente en la fibra de trigo que se destacó la capacidad de retención de agua en su modificación con microondas, y las fibras de maíz y avena que se destacaron en su capacidad de disminución del intercambio catiónico en la modificación del ultrasonido
Propiedades fisicoquímicas de cereal pigmentado con polvo de tuna roja
La tuna roja posee actividad antioxidante y potencial como colorante en la industria alimentaria, sin embargo su uso puede provocar cambios fisicoquímicos en los productos que deben ser evaluados. 2.5, 5.0 y 7.5% de polvo de tuna fueron mezclados con sémola de maíz y procesados en un extrusor de doble tornillo a 22% de humedad, 100 ºC y 325 rpm. Evaluando en los cereales propiedades físicas (humedad, densidad, color, textura e índices: expansión y solubilidad y absorción de agua,) y propiedades químicas (contenidos de polifenoles, betacianinas y betaxantinas, actividad antioxidante). Se encontró que la humedad y el índice de solubilidad en agua no presentaron dependencia al contenido de polvo adicionado. La densidad aumentó al incrementar el contenido de polvo, mientras que los índices de expansión y de absorción de agua disminuyeron con el incremento de polvo adicionado. El incremento en el polvo causó disminución de L*, b*, croma* y h* sin embargo aumentó a* y la textura de los cereales. Así como de los contenidos de polifenoles y betalainas y actividad antioxidante
Thermally activated site exchange and quantum exchange coupling processes in unsymmetrical trihydride osmium compounds
Reaction of the hexahydride complex OsH6(PiPr3)2 (1) with pyridine-2-thiol leads to the trihydride derivative OsH3{κ-N,κ-S-(2-Spy)}(PiPr3)2 (2). The structure of 2 has been determined by X-ray diffraction. The geometry around the osmium atom can be described as a distorted pentagonal bipyramid with the phosphine ligands occupying axial positions. The equatorial plane contains the pyridine-2-thiolato group, attached through a bite angle of 65.7(1)°, and the three hydride ligands. The theoretical structure determination of the model complex OsH3{κ-N,κ-S-(2-Spy)}(PH3)2 (2a) reveals that the hydride ligands form a triangle with sides of 1.623, 1.714, and 2.873 Å, respectively. A topological analysis of the electron density of 2a indicates that there is no significant electron density connecting the hydrogen atoms of the OsH3 unit. In solution, the hydride ligands of 2 undergo two different thermally activated site exchange processes, which involve the central hydride with each hydride ligand situated close to the donor atoms of the chelate group. The activation barriers of both processes are similar. Theoretical calculations suggest that the transition states have a cis-hydride−dihydrogen nature. In addition to the thermally activated exchange processes, complex 2 shows quantum exchange coupling between the central hydride and the one situated close to the sulfur atom of the pyridine-2-thiolato group. The reactions of 1 with l-valine and 2-hydroxypyridine afford OsH3{κ-N,κ-O-OC(O)CH[CH(CH3)2]NH2}(PiPr3)2 (3) and OsH3{κ-N,κ-O-(2-Opy)}(PiPr3)2 (4) respectively, which according to their spectroscopic data have a similar structure to that of 2. In solution, the hydride ligands of 3 and 4 also undergo two different thermally activated site exchange processes. However, they do not show quantum exchange coupling. The tetranuclear complexes [(PiPr3)2H3Os(μ-biim)M(TFB)]2 [M = Rh (5), Ir (6); H2biim = 2, 2‘-biimidazole; TFB = tetrafluorobenzobarrelene] have been prepared by reaction of OsH3(Hbiim)(PiPr3)2 with the dimers [M(μ-OMe)(TFB)]2 (M = Rh, Ir). In solution the hydride ligands of these complexes, which form two chemically equivalent unsymmetrical OsH3 units, undergo two thermally activated site exchanges and show two different quantum exchange coupling processes.We thank the DGICYT of Spain (Projects PB95-0806 and PB95-0639-CO2-01, Programa de Promocion
General del Conocimiento).Peer reviewe
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