Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 280
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Phys Chem Chem Phys ; 23(3): 2126-2133, 2021 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-33437974

RESUMEN

The photoinduced electron transfer is studied computationally in several Saturn-shaped inclusion complexes of carbo-aromatic rings and C60 fullerene - C72⊃C60, C96⊃C60, C120⊃C60, and C168⊃C60. Analysis of their structural and electronic properties shows that the charge separation process is efficient in C120⊃C60 and C168⊃C60 where the host molecule resembles the conjugated [24]circulene unit. In contrast, the electron transfer is not feasible in the complexes of the oligophenylene-based rings C72⊃C60 and C96⊃C60.

2.
Br J Dermatol ; 181(1): 105-113, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30451293

RESUMEN

BACKGROUND: Germline mutations in telomere-related genes such as POT1 and TERT predispose individuals to familial melanoma. OBJECTIVES: To evaluate the prevalence of germline mutations in POT1 and TERT in a large cohort of Spanish melanoma-prone families (at least two affected first- or second-degree relatives). METHODS: Overall, 228 CDKN2A wild-type melanoma-prone families were included in the study. Screening of POT1 was performed in one affected person from each family and TERT was sequenced in one affected patient from 202 families (26 families were excluded owing to DNA exhaustion/degradation). TERT promoter sequencing was extended to an additional 30 families with CDKN2A mutation and 70 patients with sporadic multiple primary melanoma (MPM) with a family history of other cancers. RESULTS: We identified four families with potentially pathogenic POT1 germline mutations: a missense variant c.233T>C (p.Ile78Thr); a nonsense variant c.1030G>T (p.Glu344*); and two other variants, c.255G>A (r.125_255del) and c.1792G>A (r.1791_1792insAGTA, p.Asp598Serfs*22), which we confirmed disrupted POT1 mRNA splicing. A TERT promoter variant of unknown significance (c.-125C>A) was detected in a patient with MPM, but no germline mutations were detected in TERT promoter in cases of familial melanoma. CONCLUSIONS: Overall, 1·7% of our CDKN2A/CDK4-wild type Spanish melanoma-prone families carry probably damaging mutations in POT1. The frequency of TERT promoter germline mutations in families with melanoma in our population is extremely rare.


Asunto(s)
Predisposición Genética a la Enfermedad , Melanoma/genética , Regiones Promotoras Genéticas/genética , Neoplasias Cutáneas/genética , Telomerasa/genética , Proteínas de Unión a Telómeros/genética , Adulto , Anciano , Codón sin Sentido , Estudios de Cohortes , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Análisis Mutacional de ADN , Femenino , Pruebas Genéticas , Mutación de Línea Germinal , Humanos , Masculino , Anamnesis , Melanoma/epidemiología , Persona de Mediana Edad , Mutación , Mutación Missense , Linaje , Complejo Shelterina , Neoplasias Cutáneas/epidemiología , España/epidemiología , Melanoma Cutáneo Maligno
3.
Phys Chem Chem Phys ; 21(45): 25098-25107, 2019 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-31690909

RESUMEN

Molecular arrays containing donor-acceptor sites and antenna molecules are promising candidates for organic photovoltaic devices. Photoinduced electron transfer (PET) in multi-chromophore systems is controlled by a subtle interplay of donor and acceptor properties and solvent effects. In the present study, we explore how PET of fullerene [C60]-Zn-porphyrin-BODIPY triads can be modulated by passing from non-polar to polar media. To this end we perform a computational study of this complex using the DFT/TDDFT method. We find that the stabilization energy of charge transfer states by a polar medium depends significantly on whether the BODIPY moiety acts as an electron donor or an electron acceptor. To understand this effect of the environment, a detailed analysis of the initial and final states of the ET reactions is performed. We show that additional deactivation channels of the porphyrin excited state may come into play as solvent polarity increases.

4.
J Microencapsul ; 36(1): 43-52, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30836027

RESUMEN

Hydrophobic bioactives can be more easily incorporated into food and have their bioavailability enhanced if nanostructured lipid carriers (NLC) are used as carriers. In the present study, beta-carotene-loaded NLC were produced by low emulsification using murumuru butter and a mixture of Span 80 and Cremophor RH40 as surfactants. Their average diameter was 35 nm and alpha-tocopherol was required to protect the encapsulated ß-carotene. Besides the evaluation of their physicochemical stability, NLC were submitted to dynamic in vitro digestion and cell viability assays with Caco-2 and HEPG cells. The bioaccessibility of beta-carotene in the dynamic system was about 42%. Regarding cell viability, results indicated NLC were toxic to the cell cultures tested. Such high toxicity is probably related to the type of surfactant used and to the extremely reduced particle size, which may have led to an intense and fast permeation of the NLC through the cells.


Asunto(s)
Antioxidantes/administración & dosificación , Portadores de Fármacos/química , Lípidos/química , Provitaminas/administración & dosificación , alfa-Tocoferol/administración & dosificación , beta Caroteno/administración & dosificación , Antioxidantes/química , Células CACO-2 , Supervivencia Celular/efectos de los fármacos , Portadores de Fármacos/toxicidad , Combinación de Medicamentos , Humanos , Lípidos/toxicidad , Magnoliopsida/química , Nanoestructuras/química , Nanoestructuras/toxicidad , Transición de Fase , Provitaminas/química , Temperatura de Transición , alfa-Tocoferol/química , beta Caroteno/química
6.
J Phys Chem A ; 122(7): 1916-1923, 2018 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-29381071

RESUMEN

The chemical formation process has been studied from relaxation holes, Δh(u), resulting from the difference between the radial intracule density and the nonrelaxed counterpart, which is obtained from atomic radial intracule densities and the pair density constructed from the overlap of the atomic densities. Δh(u) plots show that the internal reorganization of electron pairs prior to bond formation and the covalent bond formation from electrons in separate atoms are completely recognizable processes from the shape of the relaxation hole, Δh(u). The magnitude of Δh(u), the shape of Δh(u) ∀ u < Req, and the distance between the minimum and the maximum in Δh(u) provide further information about the nature of the chemical bond formed. A computational affordable approach to calculate the radial intracule density from approximate pair densities has been also suggested, paving the way to study electron-pair distributions in larger systems.

7.
Plant J ; 85(1): 107-19, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26648446

RESUMEN

Carotenoids are isoprenoid compounds that are essential for plants to protect the photosynthetic apparatus against excess light. They also function as health-promoting natural pigments that provide colors to ripe fruit, promoting seed dispersal by animals. Work in Arabidopsis thaliana unveiled that transcription factors of the phytochrome-interacting factor (PIF) family regulate carotenoid gene expression in response to environmental signals (i.e. light and temperature), including those created when sunlight reflects from or passes though nearby vegetation or canopy (referred to as shade). Here we show that PIFs use a virtually identical mechanism to modulate carotenoid biosynthesis during fruit ripening in tomato (Solanum lycopersicum). However, instead of integrating environmental information, PIF-mediated signaling pathways appear to fulfill a completely new function in the fruit. As tomatoes ripen, they turn from green to red due to chlorophyll breakdown and carotenoid accumulation. When sunlight passes through the flesh of green fruit, a self-shading effect within the tissue maintains high levels of PIFs that directly repress the master gene of the fruit carotenoid pathway, preventing undue production of carotenoids. This effect is attenuated as chlorophyll degrades, causing degradation of PIF proteins and boosting carotenoid biosynthesis as ripening progresses. Thus, shade signaling components may have been co-opted in tomato fruit to provide information on the actual stage of ripening (based on the pigment profile of the fruit at each moment) and thus finely coordinate fruit color change. We show how this mechanism may be manipulated to obtain carotenoid-enriched fruits.


Asunto(s)
Carotenoides/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Proteínas de Plantas/metabolismo , Transducción de Señal/efectos de la radiación , Solanum lycopersicum/fisiología , Clorofila/metabolismo , Ambiente , Etilenos/metabolismo , Frutas/genética , Frutas/fisiología , Frutas/efectos de la radiación , Luz , Solanum lycopersicum/genética , Solanum lycopersicum/efectos de la radiación , Fitocromo/metabolismo , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Terpenos/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
8.
New Phytol ; 216(4): 1191-1204, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28877333

RESUMEN

Protophloem and metaphloem sieve tubes are essential for transporting carbohydrates and signalling molecules towards sink tissues. OCTOPUS (OPS) was previously identified as an important regulator of protophloem differentiation in Arabidopsis roots. Here, we investigated the role of OCTOPUS-LIKE 2 (OPL2), a gene homologous to OPS. OPL2 expression patterns were analysed, and functional equivalence of OPS and OPL2 was tested. Mutant and double mutant phenotypes were investigated. OPS and OPL2 displayed overlapping expression patterns and a high degree of functional overlap. A mutation in OPL2 revealed redundant functions of OPS and OPL2 in developmental processes in which OPS was known to play a role, notably cotyledon vascular patterning and protophloem development. Moreover, we also uncovered redundant roles for OPS and OPL2 in leaf vascular patterning and, most interestingly, metaphloem sieve tube differentiation. Our results reveal a novel OPS-like protein that, together with OPS, is an important regulator of vascular patterning, root growth and phloem development. OPS and OPL2 are the first genes identified that play a role in metaphloem sieve tube differentiation.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Proteínas de la Membrana/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Haz Vascular de Plantas/crecimiento & desarrollo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de la Membrana/genética , Familia de Multigenes , Raíces de Plantas/citología , Haz Vascular de Plantas/citología
9.
Plant Physiol ; 172(3): 1393-1402, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27707890

RESUMEN

A wide diversity of isoprenoids is produced in different plant compartments. Most groups of isoprenoids synthesized in plastids, and some produced elsewhere in the plant cell derive from geranylgeranyl diphosphate (GGPP) synthesized by GGPP synthase (GGPPS) enzymes. In Arabidopsis (Arabidopsis thaliana), five genes appear to encode GGPPS isoforms localized in plastids (two), the endoplasmic reticulum (two), and mitochondria (one). However, the loss of function of the plastid-targeted GGPPS11 isoform (referred to as G11) is sufficient to cause lethality. Here, we show that the absence of a strong transcription initiation site in the G11 gene results in the production of transcripts of different lengths. The longer transcripts encode an isoform with a functional plastid import sequence that produces GGPP for the major groups of photosynthesis-related plastidial isoprenoids. However, shorter transcripts are also produced that lack the first translation initiation codon and rely on a second in-frame ATG codon to produce an enzymatically active isoform lacking this N-terminal domain. This short enzyme localizes in the cytosol and is essential for embryo development. Our results confirm that the production of differentially targeted enzyme isoforms from the same gene is a central mechanism to control the biosynthesis of isoprenoid precursors in different plant cell compartments.


Asunto(s)
Transferasas Alquil y Aril/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Arabidopsis/genética , Genes de Plantas , Transferasas Alquil y Aril/genética , Alelos , Proteínas de Arabidopsis/genética , Secuencia de Bases , Vías Biosintéticas/genética , Pruebas de Enzimas , Isoenzimas/genética , Isoenzimas/metabolismo , Ácido Mevalónico/metabolismo , Fenotipo , Plastidios/metabolismo , Biosíntesis de Proteínas/genética , Semillas/metabolismo , Fracciones Subcelulares/metabolismo , Terpenos/química , Terpenos/metabolismo , Sitio de Iniciación de la Transcripción
10.
Nanotechnology ; 28(21): 215202, 2017 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-28471754

RESUMEN

Integration of electronic circuit components onto flexible materials such as plastic foils, paper and textiles is a key challenge for the development of future smart applications. Therefore, conductive metal features need to be deposited on temperature sensitive substrates in a fast and straightforward way. The feasibility of these emerging (nano-) electronic technologies depends on the availability of well-designed deposition techniques and on novel functional metal inks. As ultrasonic spray coating (USSC) is one of the most promising techniques to meet the above requirements, innovative metal organic decomposition (MOD) inks are designed to deposit silver features on plastic foils. Various amine ligands were screened and their influence on the ink stability and the characteristics of the resulting metal depositions were evaluated to determine the optimal formulation. Eventually, silver layers with excellent performance in terms of conductivity (15% bulk silver conductivity), stability, morphology and adhesion could be obtained, while operating in a very low temperature window of 70 °C-120 °C. Moreover, the optimal deposition conditions were determined via an in-depth analysis of the ultrasonically sprayed silver layers. Applying these tailored MOD inks, the USSC technique enabled smooth, semi-transparent silver layers with a tunable thickness on large areas without time-consuming additional sintering steps after deposition. Therefore, this novel combination of nanoparticle-free Ag-inks and the USSC process holds promise for high throughput deposition of highly conductive silver features on heat sensitive substrates and even 3D objects.

11.
Phys Chem Chem Phys ; 19(32): 21276-21281, 2017 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-28766635

RESUMEN

The behavior of the entirely unique system represented by superalkaline species incorporated into a superhalogen cage has been studied using density functional theory with hybrid functionals and the triple-ξ quality basis set level of theory. The singlet ground state and triplet excited state of an FLi2@B39 borospherene complex as well as its cationic and anionic doublet ground states have been investigated. Only the encapsulation of FLi2+ into B39 in FLi2@B39+ is a thermodynamically unfavorable process. All other systems are stabilized during encapsulation most likely via an unpaired electron delocalization process and electrostatic interaction. The calculations revealed that superhalogen and superalkaline properties inherent in the separated fragments are lost in FLi2@B39 complexes. The applicability of vertically estimated ionization potentials and electron affinities instead of adiabatic ones for description of such systems has been demonstrated.

12.
J Wound Care ; 26(10): 593-599, 2017 10 02.
Artículo en Inglés | MEDLINE | ID: mdl-28976826

RESUMEN

OBJECTIVE: Hydrosurgical debridement allows removal of non-viable tissue, preserving healthy tissues. This study was designed to analyse whether hydrosurgery, used in a clinical wounds unit, is an effective and safe method that may reduce debridement time. METHODS: Patients' wounds had the following characteristics: wounds with devitalised tissue needing rapid debridement, wounds with cavities, or non-healing wounds. Hydrosurgical debridement uses a pressurised stream of saline (0.9% sodium chloride) and a vacuum around this stream to remove the devitalised tissue of the wound, preserving healthy surrounding tissues. RESULTS: This prospective study comprised of 53 wounds from 39 patients. The wound aetiology included 39.7% arterial insufficiency, 22.6% pressure ulcers (PUs), 15.1% diabetic foot ulcers (DFUs), 9.4% venous leg ulcers (VLUs), and 13.2% from other aetiologies. The percentage of wounds according the size was the following: 32.1% (<10cm2), 43.4% (10-49cm2), 15.1% (50-99cm2), and 9.4% (≥100cm2). Superficial wounds were 43.4% of the total and 56.6% of wounds had cavities. Pain associated with the hydrosurgery was mild to moderate. There were no hydrosurgery-related adverse events. For effective debridement, the required sessions were as follows: one procedure (73.6%), two procedures (18.9%) and three procedures (7.5%). There was a statistical significant direct correlation (r=0.307) between the number of required sessions and wound size. All patients improved in a week (>80% of granulation tissue). CONCLUSION: We demonstrate that hydrosurgery is an effective and rapid debridement method that can be used safely in the outpatient setting.


Asunto(s)
Desbridamiento/métodos , Pie Diabético/cirugía , Úlcera por Presión/cirugía , Solución Salina/uso terapéutico , Úlcera Varicosa/cirugía , Heridas y Lesiones/cirugía , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Úlcera de la Pierna/cirugía , Masculino , Persona de Mediana Edad , Dolor Asociado a Procedimientos Médicos , Estudios Prospectivos , Resultado del Tratamiento , Vacio
13.
Neurologia ; 32(3): 175-184, 2017 Apr.
Artículo en Inglés, Español | MEDLINE | ID: mdl-26383059

RESUMEN

INTRODUCTION: Multiple sclerosis (MS) is a demyelinating disease that affects young adults; in that age group, it represents the second leading cause of disability in our setting. Its precise aetiology has not been elucidated, but it is widely accepted to occur in genetically predisposed patients who are exposed to certain environmental factors. The discovery of the regulatory role played by intestinal microbiota in various autoimmune diseases has opened a new line of research in this field, which is discussed in this review. DEVELOPMENT: We reviewed published studies on the role of the microbiota in the development of both MS and its animal model, experimental autoimmune encephalomyelitis (EAE). In mice, it has been shown that intestinal microorganisms regulate the polarisation of T helper cells from Th1-Th17 up to Th2, the function of regulatory T cells, and the activity of B cells; they participate in the pathogenesis of EAE and contribute to its prevention and treatment. In contrast, evidence in humans is still scarce and mainly based on case-control studies that point to the presence of differences in certain bacterial communities. CONCLUSIONS: Multiple evidence points to the role of microbiota in EAE. Extrapolation of these results to MS is still in the early stages of research, and studies are needed to define which bacterial populations are associated with MS, the role they play in pathogenesis, and the therapeutic possibilities this knowledge offers us.


Asunto(s)
Encefalomielitis Autoinmune Experimental/inmunología , Microbioma Gastrointestinal/inmunología , Esclerosis Múltiple/microbiología , Animales , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/microbiología , Humanos , Ratones , Esclerosis Múltiple/inmunología
14.
Med Intensiva ; 46(11): 607-608, 2022 Nov.
Artículo en Español | MEDLINE | ID: mdl-35785241
15.
New Phytol ; 209(1): 252-64, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26224411

RESUMEN

Most plastid isoprenoids, including photosynthesis-related metabolites such as carotenoids and the side chain of chlorophylls, tocopherols (vitamin E), phylloquinones (vitamin K), and plastoquinones, derive from geranylgeranyl diphosphate (GGPP) synthesized by GGPP synthase (GGPPS) enzymes. Seven out of 10 functional GGPPS isozymes in Arabidopsis thaliana reside in plastids. We aimed to address the function of different GGPPS paralogues for plastid isoprenoid biosynthesis. We constructed a gene co-expression network (GCN) using GGPPS paralogues as guide genes and genes from the upstream and downstream pathways as query genes. Furthermore, knock-out and/or knock-down ggpps mutants were generated and their growth and metabolic phenotypes were analyzed. Also, interacting protein partners of GGPPS11 were searched for. Our data showed that GGPPS11, encoding the only plastid isozyme essential for plant development, functions as a hub gene among GGPPS paralogues and is required for the production of all major groups of plastid isoprenoids. Furthermore, we showed that the GGPPS11 protein physically interacts with enzymes that use GGPP for the production of carotenoids, chlorophylls, tocopherols, phylloquinone, and plastoquinone. GGPPS11 is a hub isozyme required for the production of most photosynthesis-related isoprenoids. Both gene co-expression and protein-protein interaction likely contribute to the channeling of GGPP by GGPPS11.


Asunto(s)
Transferasas Alquil y Aril/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Terpenos/metabolismo , Transferasas Alquil y Aril/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Carotenoides/metabolismo , Clorofila/metabolismo , Isoenzimas , Fenotipo , Fotosíntesis , Plastidios/enzimología , Fosfatos de Poliisoprenilo/metabolismo , Mapeo de Interacción de Proteínas
16.
Neurologia ; 30(9): 552-60, 2015.
Artículo en Inglés, Español | MEDLINE | ID: mdl-24975346

RESUMEN

INTRODUCTION: Multiple sclerosis is a demyelinating disease that causes severe disability in younger patients. Many epidemiology studies have confirmed a variable prevalence. The objective of this study was to analyse the prevalence of this disease in La Rioja (Spain), using such variables as age and sex; type of progression, initial form of the disease, EDSS and number of relapses; disease-modifying treatment and reasons for treatment withdrawal; personal and family history of cancer; and incidence and mortality. METHODS: Analysis of patients in La Rioja diagnosed with MS (according to Poser criteria or the 2005 McDonald criteria) during a 10-year period (2001-2011). Data were collected from hospital records, multiple sclerosis associations, and personal records kept by neurologists. RESULTS: The MS prevalence rate in La Rioja is 65 patients/100 000 inhabitants with an incidence rate of 3.5 cases/100 000 residents per year. Relapsing-remitting MS is present in 67.6% of the patient total. Mean age of onset is 20-29 years (range, 12 to 70). Most EDSS scores were mostly ≤ 2. Untreated MS cases account for 47.6% of the total and the most commonly used therapy is interferon. We detected 4 haematological tumours and 7 families with multiple members affected by MS. CONCLUSIONS: Prevalence and incidence are similar to those found in other regions Spain. The average age at onset age for primary progressive MS is slightly higher than in other papers (40-49 years). In families with multiple patients, MS may be more aggressive. Disability in these patients remains very severe. We require more epidemiology studies with a variety of data gathering methods to support findings for prevalence obtained in different provinces.


Asunto(s)
Esclerosis Múltiple/epidemiología , Adolescente , Adulto , Edad de Inicio , Anciano , Niño , Preescolar , Femenino , Humanos , Incidencia , Lactante , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple Recurrente-Remitente/epidemiología , Prevalencia , España/epidemiología , Adulto Joven
17.
Neurologia (Engl Ed) ; 39(2): 196-208, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38237804

RESUMEN

The last consensus statement of the Spanish Society of Neurology's Demyelinating Diseases Study Group on the treatment of multiple sclerosis (MS) was issued in 2016. Although many of the positions taken remain valid, there have been significant changes in the management and treatment of MS, both due to the approval of new drugs with different action mechanisms and due to the evolution of previously fixed concepts. This has enabled new approaches to specific situations such as pregnancy and vaccination, and the inclusion of new variables in clinical decision-making, such as the early use of high-efficacy disease-modifying therapies (DMT), consideration of the patient's perspective, and the use of such novel technologies as remote monitoring. In the light of these changes, this updated consensus statement, developed according to the Delphi method, seeks to reflect the new paradigm in the management of patients with MS, based on the available scientific evidence and the clinical expertise of the participants. The most significant recommendations are that immunomodulatory DMT be started in patients with radiologically isolated syndrome with persistent radiological activity, that patient perspectives be considered, and that the term "lines of therapy" no longer be used in the classification of DMTs (> 90% consensus). Following diagnosis of MS, the first DMT should be selected according to the presence/absence of factors of poor prognosis (whether epidemiological, clinical, radiological, or biomarkers) for the occurrence of new relapses or progression of disability; high-efficacy DMTs may be considered from disease onset.


Asunto(s)
Esclerosis Múltiple , Neurología , Humanos , Esclerosis Múltiple/tratamiento farmacológico , Sociedades , Consenso
18.
Plant Mol Biol ; 82(4-5): 393-416, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23729351

RESUMEN

Geranylgeranyl diphosphate (GGPP) is a key precursor of various isoprenoids that have diverse functions in plant metabolism and development. The annotation of the Arabidopsis thaliana genome predicts 12 genes to encode geranylgeranyl diphosphate synthases (GGPPS). In this study we analyzed GGPPS activity as well as the subcellular localization and tissue-specific expression of the entire protein family in A. thaliana. GGPPS2 (At2g18620), GGPPS3 (At2g18640), GGPPS6 (At3g14530), GGPPS7 (At3g14550), GGPPS8 (At3g20160), GGPPS9 (At3g29430), GGPPS10 (At3g32040) and GGPPS11 (At4g36810) showed GGPPS activity in Escherichia coli, similar to activities reported earlier for GGPPS1 (At1g49530) and GGPPS4 (At2g23800) (Zhu et al. in Plant Cell Physiol 38(3):357-361, 1997a; Plant Mol Biol 35(3):331-341, b). GGPPS12 (At4g38460) did not produce GGPP in E. coli. Based on DNA sequence analysis we propose that GGPPS5 (At3g14510) is a pseudogene. GGPPS-GFP (green fluorescent protein) fusion proteins of the ten functional GGPP synthases localized to plastids, mitochondria and the endoplasmic reticulum, with the majority of the enzymes located in plastids. Gene expression analysis using quantitative real time-PCR, GGPPS promoter-GUS (ß-glucuronidase) assays and publicly available microarray data revealed a differential spatio-temporal expression of GGPPS genes. The results suggest that plastids and mitochondria are key subcellular compartments for the synthesis of ubiquitous GGPP-derived isoprenoid species. GGPPS11 and GGPPS1 are the major isozymes responsible for their biosynthesis. All remaining paralogs, encoding six plastidial isozymes and two cytosolic isozymes, were expressed in specific tissues and/or at specific developmental stages, suggesting their role in developmentally regulated isoprenoid biosynthesis. Our results show that of the 12 predicted GGPPS encoded in the A. thaliana genome 10 are functional proteins that can synthesize GGPP. Their specific subcellular location and differential expression pattern suggest subfunctionalization in providing GGPP to specific tissues, developmental stages, or metabolic pathways.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Farnesiltransferasa/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Farnesiltransferasa/química , Farnesiltransferasa/genética , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Reacción en Cadena de la Polimerasa
19.
Psychol Med ; 43(4): 721-31, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22895096

RESUMEN

BACKGROUND: Distorted images of the observable self are considered crucial in the development and maintenance of social anxiety. We generated an experimental situation in which participants viewed themselves from an observer's perspective when exposed to scrutiny and evaluation by others. Method Twenty patients with social anxiety disorder (SAD) and 20 control subjects were assessed using functional magnetic resonance imaging (fMRI) during the public exposure of pre-recorded videos in which they were each shown performing a verbal task. The examiners acted as the audience in the experiment and rated performance. Whole-brain functional maps were computed using Statistical Parametric Mapping. RESULTS: Robust activation was observed in regions related to self-face recognition, emotional response and general arousal in both study groups. Patients showed significantly greater activation only in the primary visual cortex. By contrast, they showed significant deactivation or smaller activation in dorsal frontoparietal and anterior cingulate cortices relevant to the cognitive control of negative emotion. Task-related anxiety ratings revealed a pattern of negative correlation with activation in this frontoparietal/cingulate network. Importantly, the relationship between social anxiety scores and neural response showed an inverted-U function with positive correlations in the lower score range and negative correlations in the higher range. CONCLUSIONS: Our findings suggest that exposure to scrutiny and evaluation in SAD may be associated with changes in cortical systems mediating the cognitive components of anxiety. Disorder severity seems to be relevant in shaping the neural response pattern, which is distinctively characterized by a reduced cortical response in the most severe cases.


Asunto(s)
Trastornos de Ansiedad/fisiopatología , Mapeo Encefálico , Corteza Cerebral/fisiopatología , Emociones/fisiología , Autoimagen , Adolescente , Adulto , Trastornos de Ansiedad/psicología , Nivel de Alerta/fisiología , Estudios de Casos y Controles , Cara , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Reconocimiento en Psicología/fisiología , Índice de Severidad de la Enfermedad , Adulto Joven
20.
Nanoscale ; 15(43): 17373-17385, 2023 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-37791958

RESUMEN

Belt-shaped aromatic compounds are among the most attractive classes of radial π-conjugated nanocarbon molecules with unique physical and chemical properties. In this work, we computationally studied a number of all-carbon and heteroatom-bridged nanobelts, as well as their inclusion complexes with fullerene C60. Our results provide a useful guide for modulating the electronic properties of the nanobelts. An in-depth analysis of the ground and excited state properties of their complexes has allowed us to establish structure-property relationships and propose simple principles for the design of nanobelts with improved electron-donating properties suitable for photovoltaic applications.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA