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1.
HNO ; 70(3): 239-248, 2022 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-35075518

RESUMEN

Between 1958 and 1961 approximately 10,000 children with severe deformities of extremities were born, whose mothers had taken the sedative thalidomide. Since then, drugs in pregnancy are applied with legitimate caution by the pharmaceutical industry, physicians and patients, although often accompanied by irrational panic. The pharmaceutical industry takes a legally safe position noting "contraindication" or at least "strict indication" in the consumer information. This transfers responsibility to the prescribing doctor. Even without drug therapy, the spontaneous malformation rate is approx. 3 to 4%. Concerning expectant mothers, a therapeutic nihilism may lead to a dramatic deterioration of the maternal disease, thereby causing high risks in fetal development. The aim of the present work is to present a structured "Guideline for Practice" of medication that can be used during pregnancy for treating medical conditions of the ear, nose and throat.


Asunto(s)
Enfermedades Otorrinolaringológicas , Preparaciones Farmacéuticas , Niño , Femenino , Humanos , Enfermedades Otorrinolaringológicas/tratamiento farmacológico , Embarazo , Talidomida
2.
J Neurophysiol ; 126(1): 340-348, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-34191638

RESUMEN

During transcranial electric stimulation, increasing intracellular Ca2+ levels beyond those needed for inducing long term potentiation (LTP) may collapse aftereffects. State-dependent plastic aftereffects are reduced when applied during muscle activation as compared with rest. Cortical surround inhibition by antagonistic muscle activation inhibits the center-innervated agonist. The objective of this study is to determine the interaction of state dependency of transcranial alternating current stimulation (tACS) aftereffects at rest and under activation of agonist and antagonist muscles during stimulation with different intensities. In 13 healthy participants, we measured motor-evoked potential (MEP) amplitudes before and after applying tACS at 140 Hz over the motor cortex in nine single-blinded sessions using sham, 1 mA, and 2 mA stimulation intensities during rest and activation of agonist and antagonist muscles. During rest, only 1 mA tACS produced a significant MEP increase, whereas the 2 mA stimulation produced no significant MEP size shift. During agonist activation 1 mA did not induce MEP changes; after 2 mA, first a decrease and later an increase of MEPs were observed. Antagonist activation under sham tACS led to an inhibition, which was restored to baseline by 1 and 2 mA tACS. Increasing stimulation intensity beyond 1 mA does not increase excitability, compatible with too strong intracellular Ca2+ increase. Antagonist innervation leads to MEP inhibition, supporting the concept of surround inhibition, which can be overcome by tACS at both intensities. During agonist innervation, a tACS dose-dependent relationship exists. Our results integrate concepts of "leaky membranes" under activation, surround inhibition, intracellular Ca2+ increase, and their role in the aftereffects of tACS.NEW & NOTEWORTHY Stimulation intensity and activation of center versus surround muscles affect cortical excitability alterations generated by 140-Hz tACS. At rest, excitatory aftereffects were induced by tACS with 1 mA, but not 2 mA stimulation intensity. With agonistic muscle activation, excitability first decreases, and then increases with 2 mA. For antagonist activation, the MEP amplitude reduction observed in the sham condition is counteracted upon by 1 and 2 mA tACS. This reflects the relation of LTP-like aftereffects to Ca2+ concentration alterations.


Asunto(s)
Potenciales Evocados Motores/fisiología , Contracción Isométrica/fisiología , Músculo Esquelético/fisiología , Estimulación Transcraneal de Corriente Directa/métodos , Adulto , Estudios Cruzados , Femenino , Humanos , Masculino , Fenómenos Fisiológicos Musculoesqueléticos , Método Simple Ciego , Adulto Joven
3.
Nervenarzt ; 89(10): 1156-1164, 2018 Oct.
Artículo en Alemán | MEDLINE | ID: mdl-29736677

RESUMEN

BACKGROUND: Restless legs syndrome (RLS) is a common neurological disease. Studies have shown that RLS is associated with a variety of medical and neurological disorders. OBJECTIVES: Using the example of three associated neurological diseases, the significance for everyday therapy decisions is assessed. MATERIAL AND METHODS: A systematic search was carried out in PubMed for all studies with the keyword "RLS" in combination with polyneuropathies (PNP), Parkinson's disease (PD) and multiple sclerosis (MS) and classified according to the methodology in high, medium or low study quality. RESULTS: Of 16 studies on RLS and MS, 10 were rated as "high". The high association frequency of RLS in MS between 13.3% and 65.1% (the variability possibly originates from different methods) prevents further statements about the prevalence. Within 30 studies on Parkinson's disease 17 were classified as having a high quality. In patients with Parkinson disease RLS occurs most frequently during therapy and is related to the duration of dopaminergic treatment. In patients with polyneuropathy, only 5 out of 24 studies were classified as being of high quality and an increased RLS prevalence was detected for acquired polyneuropathies with heterogeneous data for hereditary forms. CONCLUSION: There is an increased prevalence of association with RLS for the diseases discussed. This prevalence is possibly determined by the pathophysiology of these disorders. These diseases are possibly characterized by genetic predispositions as well, which can hopefully be classified more accurately in the future.


Asunto(s)
Enfermedades Neuromusculares , Síndrome de las Piernas Inquietas , Humanos , Esclerosis Múltiple/complicaciones , Enfermedades Neuromusculares/complicaciones , Enfermedad de Parkinson/complicaciones , Polineuropatías/complicaciones , Prevalencia , Síndrome de las Piernas Inquietas/complicaciones , Síndrome de las Piernas Inquietas/epidemiología
4.
J Neurol Neurosurg Psychiatry ; 88(5): 386-394, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-27974394

RESUMEN

OBJECTIVE: To investigate the effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) of the right dorsolateral prefrontal cortex (DLPFC) on working memory performance, while measuring task-related brain activation and task-related brain connectivity in patients with multiple sclerosis (MS). METHODS: 17 patients with MS and 11 healthy controls (HCs) underwent 3 experimental sessions (baseline, real-rTMS, sham-rTMS), all including an N-back task (3 task loads: N1, N2, N3; control condition: N0) inside the MR scanner. Prior to imaging, real-rTMS (10 Hz) was applied to the right DLPFC. The stimulation site was defined based on individually assessed N-back task activation at baseline and located using neuronavigation. Changes in whole brain functional activation and functional connectivity with the right DLPFC were calculated. RESULTS: N-back task accuracy (N2 and N3) improved after real-rTMS (and not after sham-rTMS) compared with baseline (p=0.029 and p=0.015, respectively), only in patients. At baseline, patients with MS, compared with HCs, showed higher task-related frontal activation (left DLPFC, N2>N0), which disappeared after real-rTMS. Task-related (N1>N0) functional connectivity between the right DLPFC and the right caudate nucleus and bilateral (para)cingulate gyrus increased in patients after real-rTMS when compared with sham stimulation. CONCLUSIONS: In patients with MS, N-back accuracy improved while frontal hyperactivation (seen at baseline relative to HCs) disappeared after real-rTMS. Together with the changes in functional connectivity after real-rTMS in patients, these findings may represent an rTMS-induced change in network efficiency in patients with MS, shifting patients' brain function towards the healthy situation. This implicates a potentially relevant role for rTMS in cognitive rehabilitation in MS.


Asunto(s)
Mapeo Encefálico , Memoria a Corto Plazo , Esclerosis Múltiple/diagnóstico por imagen , Estimulación Magnética Transcraneal/métodos , Adulto , Núcleo Caudado , Femenino , Lateralidad Funcional/fisiología , Humanos , Imagen por Resonancia Magnética , Masculino , Esclerosis Múltiple/fisiopatología , Vías Nerviosas/fisiología , Pruebas Neuropsicológicas , Corteza Prefrontal
5.
Eur J Neurol ; 23(10): 1489-99, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27511815

RESUMEN

BACKGROUND AND PURPOSE: Our aim was to update previous European Federation of Neurological Societies guidelines on neurostimulation for neuropathic pain, expanding the search to new techniques and to chronic pain conditions other than neuropathic pain, and assessing the evidence with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. METHODS: A systematic review and meta-analysis of trials published between 2006 and December 2014 was conducted. Pain conditions included neuropathic pain, fibromyalgia, complex regional pain syndrome (CRPS) type I and post-surgical chronic back and leg pain (CBLP). Spinal cord stimulation (SCS), deep brain stimulation (DBS), epidural motor cortex stimulation (MCS), repetitive transcranial magnetic stimulation (rTMS) and transcranial direct electrical stimulation (tDCS) of the primary motor cortex (M1) or dorsolateral prefrontal cortex (DLPFC) were assessed. The GRADE system was used to assess quality of evidence and propose recommendations. RESULTS: The following recommendations were reached: 'weak' for SCS added to conventional medical management in diabetic painful neuropathy, CBLP and CRPS, for SCS versus reoperation in CBLP, for MCS in neuropathic pain, for rTMS of M1 in neuropathic pain and fibromyalgia and for tDCS of M1 in neuropathic pain; 'inconclusive' for DBS in neuropathic pain, rTMS and tDCS of the DLPFC, and for motor cortex tDCS in fibromyalgia and spinal cord injury pain. CONCLUSIONS: Given the poor to moderate quality of evidence identified by this review, future large-scale multicentre studies of non-invasive and invasive neurostimulation are encouraged. The collection of higher quality evidence of the predictive factors for the efficacy of these techniques, such as the duration, quality and severity of pain, is also recommended.


Asunto(s)
Dolor Crónico/terapia , Estimulación Encefálica Profunda/métodos , Neuralgia/terapia , Guías de Práctica Clínica como Asunto/normas , Estimulación Transcraneal de Corriente Directa/métodos , Estimulación Magnética Transcraneal/métodos , Estimulación Eléctrica Transcutánea del Nervio/métodos , Humanos
6.
Arch Virol ; 161(5): 1309-14, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26780773

RESUMEN

Cowpea mosaic virus forms tubules constructed from the movement protein (MP) in plasmodesmata (PD) to achieve cell-to-cell movement of its virions. Similar tubules, delineated by the plasma membrane (PM), are formed protruding from the surface of infected protoplasts. These PM-tubule complexes were isolated from protoplasts by immunoprecipitation and analysed for their protein content by tandem mass spectrometry to identify host proteins with affinity for the movement tubule. Seven host proteins were abundantly present in the PM-tubule complex, including molecular chaperonins and an AAA protein. Members of both protein families have been implicated in establishment of systemic infection. The potential role of these proteins in tubule-guided cell-cell transport is discussed.


Asunto(s)
Membrana Celular/virología , Comovirus/genética , Proteínas de Movimiento Viral en Plantas/fisiología , Western Blotting , Comovirus/fisiología , Fabaceae/virología , Plasmodesmos/virología , Proteómica , Protoplastos/virología
7.
Phys Chem Chem Phys ; 18(26): 17398-403, 2016 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-26659077

RESUMEN

In order to investigate the on-site motion of the diffusive species in crystalline solids, we have implemented a code to perform a time-summation of displacements of specific atoms, involving symmetry and adapted projections. The resulting 2D maps have been called 'positional recurrence maps' (PRM). Only displacements are considered, instead of positions, so static deformations are filtered out. In this paper we present the PRM method and show the type of information on the dynamics of selected atoms that can be obtained. We take, as an example, the Nd2NiO4+d system in which we were able to characterize in detail the effects of the dynamical delocalization of the apical oxygen.

8.
Nervenarzt ; 87(9): 955-66, 2016 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-27573672

RESUMEN

BACKGROUND: It is not rare that the first manifestation or relapse of an affective disorder occurs during pregnancy. Should a pharmacological treatment be indicated, the selection of a suitable substance should be made on a basis which is as safe as possible. Even when treating women of childbearing age it should be assured that the psychotropic drug selected is safe to use during pregnancy as a high percentage of pregnancies are unplanned. OBJECTIVE: When assessing the risks and benefits of psychopharmacotherapy in women who are or wish to get pregnant, not only the exposure of the child to potentially teratogenic drug effects but also potential complications during or after pregnancy and long-term neuropsychological issues need to be addressed. METHODS: This article provides an overview of the currently available literature on the use of antidepressants and mood stabilizers during pregnancy. RESULTS: A growing body of increasingly reliable data for many antidepressants and mood stabilizers are available, which allow a good prediction of their suitability for use during pregnancy and lactation. CONCLUSION: When treating affective disorders during pregnancy an individual assessment of the benefits and risks for mother and child is required. The benefit of an appropriate treatment for the mother by including medication which may be potentially harmful to the child versus the risk of an insufficient treatment for the mother by excluding medication which may be potentially harmful to both the mother and the child need to be weighed up. When a suitable psychopharmacotherapy during pregnancy has been selected, the risk for mother and child can be minimized by incorporation of therapeutic drug monitoring.


Asunto(s)
Anomalías Inducidas por Medicamentos/prevención & control , Antidepresivos/administración & dosificación , Antimaníacos/administración & dosificación , Trastornos del Humor/tratamiento farmacológico , Complicaciones del Embarazo/tratamiento farmacológico , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Anomalías Inducidas por Medicamentos/etiología , Antidepresivos/efectos adversos , Antimaníacos/efectos adversos , Monitoreo de Drogas/métodos , Medicina Basada en la Evidencia , Femenino , Alemania , Humanos , Trastornos del Humor/prevención & control , Trastornos del Humor/psicología , Atención Posnatal/métodos , Embarazo , Complicaciones del Embarazo/prevención & control , Complicaciones del Embarazo/psicología , Efectos Tardíos de la Exposición Prenatal/prevención & control , Resultado del Tratamiento
9.
Nervenarzt ; 87(9): 943-54, 2016 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-27573673

RESUMEN

BACKGROUND: When administering psychotropic drugs during pregnancy not only the potential teratogenic effects on the child must be addressed but also the fetotoxic implications for pregnancy and/or the peripartum phase as well as possible neurocognitive developmental disorders must be considered. OBJECTIVE: Evaluation of the risks and benefits of administering psychotropic drugs during pregnancy or for women who wish to become pregnant. METHODS: The literature has been reviewed with the purpose of providing information on psychotropic drugs which can safely be administered during pregnancy. The review considers antipsychotics as well as tranquilizers and hypnotics. RESULTS: Data are available for a multitude of psychotropic drugs that allow a safe estimation on their suitability for use during pregnancy. CONCLUSION: When treating mental illnesses during pregnancy the option of administering drugs must not principally be ruled out. What is required is an individual assessment of benefits and risks. The risk of an untreated mental illness versus the benefit of a suitable treatment, which may include the use of medication and the potential harm to the infant must be evaluated. If certain rules are observed and a suitable drug is selected the risk to the newborn child and/or mother during pregnancy can be minimized. During pregnancy, therapeutic drug monitoring is indicated and increases the safety for use of drugs and preventing harm to both mother and infant.


Asunto(s)
Anomalías Inducidas por Medicamentos/prevención & control , Antipsicóticos/administración & dosificación , Hipnóticos y Sedantes/administración & dosificación , Trastornos Mentales/tratamiento farmacológico , Complicaciones del Embarazo/tratamiento farmacológico , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Tranquilizantes/administración & dosificación , Anomalías Inducidas por Medicamentos/etiología , Esquema de Medicación , Monitoreo de Drogas/métodos , Quimioterapia Combinada/métodos , Medicina Basada en la Evidencia , Femenino , Humanos , Intercambio Materno-Fetal/efectos de los fármacos , Embarazo , Efectos Tardíos de la Exposición Prenatal/prevención & control , Psicofarmacología , Resultado del Tratamiento
10.
Neth Heart J ; 24(4): 227-36, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26909795

RESUMEN

Heart failure with preserved ejection fraction (HFpEF) represents a complex and heterogeneous clinical syndrome, which is increasingly prevalent and associated with poor outcome. In contrast to heart failure with reduced ejection fraction (HFrEF), modern heart failure pharmacotherapy did not improve outcome in HFpEF, which was attributed to incomplete understanding of HFpEF pathophysiology, patient heterogeneity and lack of insight into primary pathophysiological processes. HFpEF patients are frequently elderly females and patients demonstrate a high prevalence of non-cardiac comorbidities, which independently adversely affect myocardial structural and functional remodelling. Furthermore, although diastolic left ventricular dysfunction represents the dominant abnormality in HFpEF, numerous ancillary mechanisms are frequently present, which also negatively impact on cardiovascular reserve. Over the past decade, clinical and translational research has improved insight into HFpEF pathophysiology and the importance of comorbidities and patient heterogeneity. Recently, a new paradigm for HFpEF was proposed, which states that comorbidities drive myocardial dysfunction and remodelling in HFpEF through coronary microvascular inflammation. Regarding the conceptual framework of HFpEF treatment, emphasis may need to shift from a 'one fits all' strategy to an individualised approach based on phenotypic patient characterisation and diagnostic and pathophysiological stratification of myocardial disease processes. This review will describe these novel insights from a pathophysiological standpoint.

12.
Neurogenetics ; 15(1): 1-11, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24567226

RESUMEN

Val66Met (rs6265) is a gene variation, a single nucleotide polymorphism (SNP) in the brain-derived neurotrophic factor (BDNF) gene that codes for the protein BDNF. The substitution of Met for Val occurs at position 66 in the pro-region of the BDNF gene and is responsible for altered activity-dependent release and recruitment of BDNF in neurons. This is believed to manifest itself in an altered ability in neuroplasticity induction and an increased predisposition toward a number of neurological disorders. Many studies using neuroplasticity-inducing protocols have investigated the impact of the BDNF polymorphism on cortical modulation and plasticity; however, the results are partly contradictory and dependent on the paradigm used in a given study. The aim of this review is to summarize recent knowledge on the relationship of this BDNF SNP and neuroplasticity.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/fisiología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Neuronas/metabolismo , Estimulación Magnética Transcraneal/métodos , Animales , Encéfalo/metabolismo , Sistema Nervioso Central/metabolismo , Homocigoto , Humanos , Aprendizaje , Memoria , Metionina/química , Plasticidad Neuronal , Polimorfismo de Nucleótido Simple , Sinapsis/fisiología , Valina/química
13.
Neuropathol Appl Neurobiol ; 40(3): 337-44, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23822828

RESUMEN

AIMS: Desmoplastic infantile astrocytoma/ganglioglioma (DIA/DIG) is a rare primary neuroepithelial brain tumour typically affecting paediatric patients younger than 24 months. Knowledge about genetic alterations in DIA/DIG is limited. However, a previous study on BRAF V600E mutation in paediatric glioma revealed a BRAF mutation in one of two tested DIAs/DIGs. The limited number of cases in that study did not allow any conclusion about mutation frequency of BRAF in this tumour entity. METHODS: We collected a series of 18 DIAs/DIGs for testing BRAF V600E mutational status by BRAF V600E immunohistochemistry (clone VE1). Cases with sufficient DNA were tested for BRAF V600E mutation by pyrosequencing. RESULTS: Three out of 18 DIAs/DIGs presented with VE1 binding. A considerable proportion of BRAF V600E mutated tumour cells was detected in the cortical tumour component, whereas the pronounced leptomeningeal tumoural stroma was predominantly negative for VE1 binding. Pyrosequencing confirmed BRAF V600E mutation in two of three VE1-positive cases. CONCLUSION: BRAF V600E mutation affects a subset of DIAs/DIGs and offers new therapeutic opportunities.


Asunto(s)
Astrocitoma/genética , Neoplasias Encefálicas/genética , Ganglioglioma/genética , Proteínas Proto-Oncogénicas B-raf/genética , Astrocitoma/metabolismo , Neoplasias Encefálicas/metabolismo , Preescolar , Femenino , Ganglioglioma/metabolismo , Humanos , Lactante , Masculino , Mutación , Proteínas Proto-Oncogénicas B-raf/metabolismo
14.
Opt Express ; 22(14): 17079-91, 2014 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-25090522

RESUMEN

We propose and experimentally demonstrate the working principles of two novel microwave photonic (MWP) beamformer circuits operating with phase modulation (PM) and direct detection (DD). The proposed circuits incorporate two major signal processing functionalities, namely a broadband beamforming network employing ring resonator-based delay lines and an optical sideband manipulator that renders the circuit outputs equivalent to those of intensity-modulated MWP beamformers. These functionalities allow the system to employ low-circuit-complexity modulators and detectors, which brings significant benefits on the system construction cost and operation stability. The functionalities of the proposed MWP beamformer circuits were verified in experimental demonstrations performed on two sample circuits realized in Si(3)N(4)/SiO(2) waveguide technology. The measurements exhibit a 2 × 1 beamforming effect for an instantaneous RF transmission band of 3‒7 GHz, which is, to our best knowledge, the first verification of on-chip MWP beamformer circuits operating with PM and DD.

15.
J Physiol ; 591(7): 1987-2000, 2013 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-23339180

RESUMEN

Transcranial direct current stimulation (tDCS) of the human motor cortex at an intensity of 1 mA with an electrode size of 35 cm(2) has been shown to induce shifts of cortical excitability during and after stimulation. These shifts are polarity-specific with cathodal tDCS resulting in a decrease and anodal stimulation in an increase of cortical excitability. In clinical and cognitive studies, stronger stimulation intensities are used frequently, but their physiological effects on cortical excitability have not yet been explored. Therefore, here we aimed to explore the effects of 2 mA tDCS on cortical excitability. We applied 2 mA anodal or cathodal tDCS for 20 min on the left primary motor cortex of 14 healthy subjects. Cathodal tDCS at 1 mA and sham tDCS for 20 min was administered as control session in nine and eight healthy subjects, respectively. Motor cortical excitability was monitored by transcranial magnetic stimulation (TMS)-elicited motor-evoked potentials (MEPs) from the right first dorsal interosseous muscle. Global corticospinal excitability was explored via single TMS pulse-elicited MEP amplitudes, and motor thresholds. Intracortical effects of stimulation were obtained by cortical silent period (CSP), short latency intracortical inhibition (SICI) and facilitation (ICF), and I wave facilitation. The above-mentioned protocols were recorded both before and immediately after tDCS in randomized order. Additionally, single-pulse MEPs, motor thresholds, SICI and ICF were recorded every 30 min up to 2 h after stimulation end, evening of the same day, next morning, next noon and next evening. Anodal as well as cathodal tDCS at 2 mA resulted in a significant increase of MEP amplitudes, whereas 1 mA cathodal tDCS decreased corticospinal excitability. A significant shift of SICI and ICF towards excitability enhancement after both 2 mA cathodal and anodal tDCS was observed. At 1 mA, cathodal tDCS reduced single-pulse TMS-elicited MEP amplitudes and shifted SICI and ICF towards inhibition. No significant changes were observed in the other protocols. Sham tDCS did not induce significant MEP alterations. These results suggest that an enhancement of tDCS intensity does not necessarily increase efficacy of stimulation, but might also shift the direction of excitability alterations. This should be taken into account for applications of the stimulation technique using different intensities and durations in order to achieve stronger or longer lasting after-effects.


Asunto(s)
Corteza Motora/fisiología , Adulto , Estimulación Eléctrica/métodos , Electrodos , Potenciales Evocados Motores , Femenino , Humanos , Masculino , Inhibición Neural , Estimulación Magnética Transcraneal , Adulto Joven
17.
Opt Express ; 21(19): 22937-61, 2013 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-24104179

RESUMEN

We present an overview of several microwave photonic processing functionalities based on combinations of Mach-Zehnder and ring resonator filters using the high index contrast silicon nitride (TriPleX™) waveguide technology. All functionalities are built using the same basic building blocks, namely straight waveguides, phase tuning elements and directional couplers. We recall previously shown measurements on high spurious free dynamic range microwave photonic (MWP) link, ultra-wideband pulse generation, instantaneous frequency measurements, Hilbert transformers, microwave polarization networks and demonstrate new measurements and functionalities on a 16 channel optical beamforming network and modulation format transformer as well as an outlook on future microwave photonic platform integration, which will lead to a significantly reduced footprint and thereby enables the path to commercially viable MWP systems.

18.
Nature ; 450(7172): 1062-5, 2007 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-18075589

RESUMEN

Conventional high-temperature reactions limit the control of coordination polyhedra in transition-metal oxides to those obtainable within the bounds of known coordination geometries for a given transition metal. For example, iron atoms are almost exclusively coordinated by three-dimensional polyhedra such as tetrahedra and octahedra. However, recent works have shown that binary metal hydrides act as reducing agents at low temperatures, allowing access to unprecedented structures. Here we show the reaction of a perovskite SrFeO3 with CaH2 to yield SrFeO2, a new compound bearing a square-planar oxygen coordination around Fe2+. SrFeO2 is isostructural with 'infinite layer' cupric oxides, and exhibits a magnetic order far above room temperature in spite of the two-dimensional structure, indicating strong in-layer magnetic interactions due to strong Fe d to O p hybridization. Surprisingly, SrFeO2 remains free from the structural instability that might well be expected at low temperatures owing to twofold orbital degeneracy in the Fe2+ ground state with D(4h) point symmetry. The reduction and the oxidation between SrFeO2 and SrFeO3 proceed via the brownmillerite-type intermediate SrFeO2.5, and start at the relatively low temperature of approximately 400 K, making the material appealing for a variety of applications, including oxygen ion conduction, oxygen gas absorption and catalysis.

19.
Pathologe ; 34(3): 186-97, 2013 May.
Artículo en Alemán | MEDLINE | ID: mdl-23471726

RESUMEN

The differential diagnosis of lymphoid lesions in the central nervous system covers a broad spectrum of neoplastic and inflammatory disorders. Complex cases benefit from the combined expertise in the fields of hematopoietic and neuroepithelial tumors as well as neuroimmunology. The Network Lymphomas and Lymphomatoid Lesions in the Nervous System (NLLLN) recommends performing a biopsy prior to any therapeutic intervention as a precise diagnosis was impossible in approximately 50 % of patients pretreated with corticosteroids. This is based on the analysis of approximately 1,000 cases in the past 4 years. In addition to total NLLLN experiences the characteristics, pathogenesis and differential diagnosis of primary lymphoma of the central nervous system are discussed.


Asunto(s)
Neoplasias del Sistema Nervioso Central/patología , Linfoma/patología , Seudolinfoma/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Biopsia , Proliferación Celular , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/patología , Neoplasias del Sistema Nervioso Central/genética , Niño , Preescolar , Análisis Mutacional de ADN , Diagnóstico Diferencial , Femenino , Humanos , Linfoma/genética , Masculino , Persona de Mediana Edad , FN-kappa B/genética , Seudolinfoma/genética , Receptores de Antígenos de Linfocitos B/genética , Transducción de Señal/genética , Adulto Joven
20.
Ann Nutr Metab ; 60(1): 69-77, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22343754

RESUMEN

BACKGROUND AND AIMS: To investigate associations between baseline serum 25-hydroxyvitamin D [25(OH)D] levels and myocardial structure and function after 8 years of follow-up in older Dutch subjects. METHODS: We included 256 subjects of the Hoorn Study, a population-based cohort. They underwent a standardized 2-dimensional echocardiogram at baseline between 2000 and 2001, and again between 2007 and 2009. We studied the association of 25(OH)D quartiles with echocardiographic measures of the left ventricular mass index (LVMI), left ventricular systolic function and markers of diastolic function using linear regression analyses. RESULTS: At baseline, subjects had a mean age of 67.4 ± 5.2 years and 41.4% had prior cardiovascular disease (CVD). Low serum 25(OH)D levels were only associated with higher LVMI at 8-year follow-up in subjects without prior CVD and in subjects with low kidney function (median estimated glomerular filtration rate ≤77.5 ml/min/1.73m(2)). The associations attenuated after adjustments for parathyroid hormone (PTH), which was associated with higher LVMI (g/m(2.7)) in subjects with low kidney function (regression coefficient highest quartile 6.3, 95% CI: 0.2, 12.5). CONCLUSION: This study showed no strong associations of 25(OH)D with myocardial structure and function. However, PTH - a possible modifiable mediator in the relation between 25(OH)D and myocardial structure - was positively associated with LVMI in subjects with low kidney function.


Asunto(s)
25-Hidroxivitamina D 2/sangre , Calcifediol/sangre , Corazón/fisiología , Miocardio/ultraestructura , Deficiencia de Vitamina D/epidemiología , Anciano , Antropometría , Glucemia/análisis , Presión Sanguínea , Comorbilidad , Diástole , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Hipertrofia Ventricular Izquierda/sangre , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Hipertrofia Ventricular Izquierda/epidemiología , Hipertrofia Ventricular Izquierda/etiología , Enfermedades Renales/sangre , Enfermedades Renales/epidemiología , Lípidos/sangre , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Hormona Paratiroidea/sangre , Factores de Riesgo , Factores Socioeconómicos , Sístole , Ultrasonografía , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/complicaciones , Deficiencia de Vitamina D/fisiopatología
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