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1.
Arch Gynecol Obstet ; 301(2): 405-414, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31781889

RESUMEN

PURPOSE: Prenatal stress (PS) during pregnancy affects in utero- and postnatal child brain-development. Key systems affected are the hypothalamic-pituitary-adrenal axis and the autonomic nervous system (ANS). Maternal- and fetal ANS activity can be gauged non-invasively from transabdominal electrocardiogram (taECG). We propose a novel approach to assess couplings between maternal (mHR) and fetal heart rate (fHR) as a new biomarker for PS based on bivariate phase-rectified signal averaging (BPRSA). We hypothesized that PS exerts lasting impact on fHR. METHODS: Prospective case-control study matched for maternal age, parity, and gestational age during the third trimester using the Cohen Perceived Stress Scale (PSS-10) questionnaire with PSS-10 over or equal 19 classified as stress group (SG). Women with PSS-10 < 19 served as control group (CG). Fetal electrocardiograms were recorded by a taECG. Coupling between mHR and fHR was analyzed by BPRSA resulting in fetal stress index (FSI). Maternal hair cortisol, a memory of chronic stress exposure for 2-3 months, was measured at birth. RESULTS: 538/1500 pregnant women returned the questionnaire, 55/538 (10.2%) mother-child pairs formed SG and were matched with 55/449 (12.2%) consecutive patients as CG. Maternal hair cortisol was 86.6 (48.0-169.2) versus 53.0 (34.4-105.9) pg/mg (p = 0.029). At 36 + 5 weeks, FSI was significantly higher in fetuses of stressed mothers when compared to controls [0.43 (0.18-0.85) versus 0.00 (- 0.49-0.18), p < 0.001]. CONCLUSION: Prenatal maternal stress affects the coupling between maternal and fetal heart rate detectable non-invasively a month prior to birth. Lasting effects on neurodevelopment of affected offspring should be studied. TRIAL REGISTRATION: Clinical trial registration: NCT03389178.


Asunto(s)
Ansiedad/fisiopatología , Sistema Nervioso Autónomo/fisiología , Movimiento Fetal/fisiología , Frecuencia Cardíaca Fetal/fisiología , Madres/psicología , Complicaciones del Embarazo/psicología , Estrés Psicológico/fisiopatología , Adulto , Estudios de Casos y Controles , Electrocardiografía , Femenino , Edad Gestacional , Humanos , Hidrocortisona/análisis , Sistema Hipotálamo-Hipofisario , Sistema Hipófiso-Suprarrenal , Embarazo , Tercer Trimestre del Embarazo , Estudios Prospectivos , Estrés Psicológico/complicaciones
2.
J Chem Phys ; 149(13): 134301, 2018 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-30292203

RESUMEN

Photoionization of randomly oriented chiral molecules with circularly polarized light leads to a strong forward/backward asymmetry in the photoelectron angular distribution. This chiroptical effect, referred to as Photoelectron Circular Dichroism (PECD), was shown to take place in all ionization regimes, from single photon to tunnel ionization. In the Resonance Enhanced Multiphoton Ionisation (REMPI) regime, where most of the table-top PECD experiments have been performed, understanding the role of the intermediate resonances is currently the subject of experimental and theoretical investigations. In an attempt to decouple the role of bound-bound and bound-continuum transitions in REMPI-PECD, we photoionized the (+)-limonene enantiomer using two-color laser fields in [1 + 1'] and [2 + 2'] ionization schemes, where the polarization state of each color can be controlled independently. We demonstrate that the main effect of the bound-bound transition is to break the sample isotropy by orientation-dependent photoexcitation, in agreement with recent theoretical predictions. We show that the angular distribution of PECD strongly depends on the anisotropy of photoexcitation to the intermediate state, which is different for circularly and linearly polarized laser pulses. On the contrary, the helicity of the pulse that drives the bound-bound transition is shown to have a negligible effect on the PECD.

3.
J Acoust Soc Am ; 141(1): 383, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-28147599

RESUMEN

Through the comparison of notes produced on two recorders by one novice and two experienced players in musical contexts, this study identifies the temporal aspects of the attack transients which are controlled by the player and those which are imposed by the dynamic response of the instrument. The rise times of mouth pressure used by the novice player are longer than the ones produced by the experienced players, which are the shortest ones preserving the control of the jet velocity rise times. For shortest rise times, the jet development is limited by the inertia of the channel. The onset time of the acoustic oscillation is divided in two parts: the time needed to initiate the oscillation and the duration of the growth. The times of growth are similar for the novice and the experienced players, which is linked to the similarity of the gain characterizing the linear behavior of the instrument. The times needed to initiate the oscillation show the most pronounced difference between the two types of players; it is much longer for a novice player. This difference is interpreted in terms of the initial input of energy in the system which is larger for the experienced players.

4.
Phys Rev Lett ; 116(5): 053002, 2016 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-26894708

RESUMEN

Probing electronic wave functions of polyatomic molecules is one of the major challenges in high-harmonic spectroscopy. The extremely nonlinear nature of the laser-molecule interaction couples the multiple degrees of freedom of the probed system. We combine two-dimensional control of the electron trajectories and vibrational control of the molecules to disentangle the two main steps in high-harmonic generation-ionization and recombination. We introduce a new measurement scheme, frequency-resolved optomolecular gating, which resolves the temporal amplitude and phase of the harmonic emission from excited molecules. Focusing on the study of vibrational motion in N_{2}O_{4}, we show that such advanced schemes provide a unique insight into the structural and dynamical properties of the underlying mechanism.

5.
J Endocrinol Invest ; 38(9): 951-6, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25740070

RESUMEN

PURPOSE: Insulin-like growth factor I (IGF-I) represents an essential tool in the diagnostic work-up and in the monitoring of treatment efficacy for somatotrophic axis disorders both in children and adults. A large number of factors including, but not limited to, age, sex and weight as well as analytical variables influence IGF-I serum levels; therefore, reliable normative data are essential for a correct interpretation of results. The aim of the present study was to establish reference range values for serum IGF-I, in a large population of healthy adults from Buenos Aires city. METHODS: The study included serum samples from 1044 healthy subjects aged 21-87 years (423 females and 621 males) divided into groups by sex at 5-year intervals from 21 to >75 years. Serum IGF-I concentrations were determined by a fully automated two-site, solid-phase, enzyme-labeled chemiluminescent immunometric assay (Immulite 2000, Siemens Healthcare Diagnostics). IGF-BP interferences are circumvented by blocking IGF-BP binding sites with excess IGF-II in the on-board predilution step. RESULTS: Results show the age dependence of circulating IGF-I levels, with a smooth and steady decrease in levels with age. No sex differences were found in subjects >26 years; however, in the group aged 21-25 years, IGF-I levels were significantly higher in females. In conclusion, this study provides age- and gender-adjusted normal reference ranges for IGF-I levels obtained with an automated immunometric chemiluminescent assay Immulite 2000 in healthy adult subjects.


Asunto(s)
Trastornos del Crecimiento/diagnóstico , Factor I del Crecimiento Similar a la Insulina/análisis , Mediciones Luminiscentes/métodos , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Argentina , Femenino , Trastornos del Crecimiento/sangre , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Factores Sexuales , Adulto Joven
6.
J Eur Acad Dermatol Venereol ; 28 Suppl 4: 1-18, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24931580

RESUMEN

The skin is the largest organ of the body, providing a protective barrier against bacteria, chemicals and physical insults while maintaining homeostasis in the internal environment. Such a barrier function the skin ensures protection against excessive water loss. The skin's immune defence consists of several facets, including immediate, non-specific mechanisms (innate immunity) and delayed, stimulus-specific responses (adaptive immunity), which contribute to fending off a wide range of potentially invasive microorganisms. This article is an overview of all known data about 'fragile skin'. Fragile skin is defined as skin with lower resistance to aggressions. Fragile skin can be classified into four categories up to its origin: physiological fragile skin (age, location), pathological fragile skin (acute and chronic), circumstantial fragile skin (due to environmental extrinsic factors or intrinsic factors such as stress) and iatrogenic fragile skin. This article includes the epidemiologic data, pathologic description of fragile skin with pathophysiological bases (mechanical and immunological role of skin barrier) and clinical description of fragile skin in atopic dermatitis, in acne, in rosacea, in psoriasis, in contact dermatitis and other dermatologic pathologies. This article includes also clinical cases and differential diagnosis of fragile skin (reactive skin) in face in adult population. In conclusion, fragile skin is very frequent worldwide and its prevalence varies between 25% and 52% in Caucasian, African and Asian population.


Asunto(s)
Epidermis/patología , Epidermis/fisiología , Enfermedades de la Piel/patología , Enfermedades de la Piel/fisiopatología , Acné Vulgar/patología , Acné Vulgar/fisiopatología , Acné Vulgar/terapia , Avena , Dermatitis Atópica/patología , Dermatitis Atópica/fisiopatología , Dermatitis Atópica/terapia , Dermatitis por Contacto/patología , Dermatitis por Contacto/fisiopatología , Dermatitis por Contacto/terapia , Eccema/patología , Eccema/fisiopatología , Eccema/terapia , Emolientes/farmacología , Emolientes/uso terapéutico , Epidermis/efectos de los fármacos , Epidermis/inmunología , Epidermis/fisiopatología , Epidermólisis Ampollosa/patología , Epidermólisis Ampollosa/fisiopatología , Epidermólisis Ampollosa/terapia , Humanos , Fitoterapia , Extractos Vegetales/uso terapéutico , Psoriasis/patología , Psoriasis/fisiopatología , Psoriasis/terapia , Retinoides/farmacología , Retinoides/uso terapéutico , Enfermedades de la Piel/inmunología , Enfermedades de la Piel/terapia
7.
J Acoust Soc Am ; 135(6): 3221-30, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24907787

RESUMEN

A simple analytical model for the interaction between a plane jet issued from a flue and a transverse acoustic disturbance is developed in this paper. The model is inspired by direct flow simulation results confronted to experimental data. The interaction is expected to take place in the vicinity of the separation points of the jet. The influence of the detailed geometry of the channel end on the jet receptivity is discussed, and more specifically the chamfer geometries found in flute-like musical instruments. The simplified model explains quite well the difference between the jet response of a flue with square edges compared to a chamfered flue exit. The effect of rounded, lip-like flue exit is not well captured by the model.

8.
Phys Rev Lett ; 110(8): 083902, 2013 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-23473148

RESUMEN

High order harmonic generation from clusters is a controversial topic: conflicting theories exist, with different explanations for similar experimental observations. From an experimental point of view, separating the contributions from monomers and clusters is challenging. By performing a spectrally and spatially resolved study in a controlled mixture of clusters and monomers, we are able to isolate a region of the spectrum where the emission purely originates from clusters. Surprisingly, the emission from clusters is depolarized, which is the signature of statistical inhomogeneous emission from a low-density source. The harmonic response to laser ellipticity shows that this generation is produced by a new recollisional mechanism, which opens the way to future theoretical studies.

9.
Neuroimage ; 62(1): 510-9, 2012 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-22584228

RESUMEN

Enforced limb disuse strongly disrupts the cortical networks that are involved in sensorimotor activities. This disruption causes a cortical reorganization that may be functionally maladaptive. In this study, we used functional magnetic resonance imaging (fMRI) to investigate whether it is possible to prevent this reorganization by compensating for the lack of actual kinesthetic perception with illusory movements induced by "neuromimetic" proprio-tactile feedback that is artificially delivered during immobilization. Sixteen healthy volunteers were equipped for five days with full-hand ortheses that prevented them from performing finger and hand movements but allowed for kinesthetic and tactile sensations. Eight participants received a twice-daily proprio-tactile treatment consisting of the perception of kinesthetic sensations resembling those felt during actual movements generated by miniature vibrators set in the ortheses at the finger and wrist levels. Eight untreated participants received no stimulation. The effects of hand immobilization and treatment were assessed by fMRI during a calibrated voluntary hand movement task and hand tactile stimulation before cast placement and immediately after cast removal. We found that the sensorimotor network was preserved in subjects who underwent this treatment during hand immobilization, while the sensorimotor network of untreated subjects was significantly altered. These findings suggest that sensory feedback and associated movement perception may counteract disuse-induced cortical plastic changes through recruitment of a large part of the cortical network used for actual performed movement. The possibility of guiding cortical plasticity with proprioceptive augmented feedback is potentially relevant for rehabilitation efforts.


Asunto(s)
Encéfalo/fisiología , Retroalimentación Sensorial/fisiología , Ilusiones/fisiología , Imaginación/fisiología , Inmovilización/métodos , Movimiento/fisiología , Enmascaramiento Perceptual/fisiología , Adulto , Señales (Psicología) , Femenino , Humanos , Masculino , Red Nerviosa/fisiología , Adulto Joven
10.
Ann Oncol ; 23(9): 2386-2390, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22422944

RESUMEN

BACKGROUND: To evaluate the efficacy of extracorporeal photopheresis (ECP) in noncutaneous T-cell lymphoma and large granular lymphocytes leukemia (LGL). PATIENTS AND METHODS: We have treated 12 refractory/relapsed patients. Six peripheral T-cell lymphoma (PTCL), one T-lymphoblastic lymphoma and five LGL with blood involvement received six biweekly leukapheresis as induction phase, followed by one course a week for 4 weeks as consolidation and one course of maintenance per month for responders until progression/relapse or disappearance of the peripheral clone. RESULTS: Six patients responded to phototherapy. Two PTCL and two LGL achieved a complete response (CR) and two other PTCL a partial response. The median duration of CR was 117 months (45-150 months) for these four patients. The peripheral clone followed by flow cytometry decreased in all six responders. Two patients with a complete disappearance of the peripheral clone have not relapsed. CONCLUSIONS: As for cutaneous T-cell lymphoma, ECP therefore to be efficient for PTCL and LGL. Early decrease and disappearance of the peripheral clone were the indicators of clinical response and nonrelapse, respectively.


Asunto(s)
Leucemia Linfocítica Granular Grande/tratamiento farmacológico , Linfoma de Células T/tratamiento farmacológico , Fotoféresis , Adulto , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
11.
Phys Rev Lett ; 108(20): 203001, 2012 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-23003145

RESUMEN

Recollision processes provide direct insight into the structure and dynamics of electronic wave functions. However, the strength of the process sets its basic limitations--the interaction couples numerous degrees of freedom. In this Letter we decouple the basic steps of the process and resolve the role of the ionic potential which is at the heart of a broad range of strong field phenomena. Specifically, we measure high harmonic generation from argon atoms. By manipulating the polarization of the laser field we resolve the vectorial properties of the interaction. Our study shows that the ionic core plays a significant role in all steps of the interaction. In particular, Coulomb focusing induces an angular deflection of the electrons before recombination. A complete spatiospectral analysis reveals the influence of the potential on the spatiotemporal properties of the emitted light.


Asunto(s)
Electrones , Modelos Teóricos , Argón/química , Iones/química , Termodinámica
12.
Phytopathology ; 102(1): 47-54, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22165983

RESUMEN

Dothistroma needle blight (DNB) emerged in France in the past 15 years. This disease is induced by two closely related species: Dothistroma septosporum and D. pini. Although both species are currently present in France, only D. septosporum was reported in the past. We investigated whether a recent arrival of D. pini in France could be a cause of the DNB emergence. We analyzed herbarium specimens of pine needles with DNB symptoms using polymerase chain reaction techniques to study the past frequency of D. pini in France. We also determined the present distribution within the country of D. septosporum and D. pini and compared it with the spatial pattern of DNB reported in the Département de la Santé des Forêts (DSF; French forest health monitoring agency) database. Although D. pini was detected on herbarium specimens from 1907 and 1965, it was not frequent in France in the past. Today, it is frequent, although not present throughout the country, being absent from the north and the east. There is no relationship between the D. pini distribution in France and the spatial pattern of DNB reported in the DSF database. Thus, the emergence of DNB in France cannot be explained by a recent arrival of D. pini.


Asunto(s)
Ascomicetos/aislamiento & purificación , Pinus/microbiología , Enfermedades de las Plantas/microbiología , Animales , Ascomicetos/fisiología , Clima , Francia , Mariposas Nocturnas/microbiología , Enfermedades de las Plantas/estadística & datos numéricos , Hojas de la Planta/microbiología , Reacción en Cadena de la Polimerasa/métodos , Árboles
13.
J Chem Phys ; 137(22): 224303, 2012 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-23248999

RESUMEN

We study theoretically and experimentally the electronic relaxation of NO(2) molecules excited by absorption of one ∼400 nm pump photon. Semiclassical simulations based on trajectory surface hopping calculations are performed. They predict fast oscillations of the electronic character around the intersection of the ground and first excited diabatic states. An experiment based on high-order harmonic transient grating spectroscopy reveals dynamics occurring on the same time scale. A systematic study of the detected transient is conducted to investigate the possible influence of the pump intensity, pump wavelength, and rotational temperature of the molecules. The quantitative agreement between measured and predicted dynamics shows that, in NO(2), high harmonic transient grating spectroscopy encodes vibrational dynamics underlying the electronic relaxation.

14.
Sci Rep ; 12(1): 10309, 2022 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-35725989

RESUMEN

The aim of the study was to evaluate adrenal axis hyperactivation measuring hair cortisol levels, and its influence on the relationship among metabolic parameters, inflammation markers and androgens in adult women with PCOS. 44 women (18-34 years) with PCOS diagnosis and a control group of 49 healthy women (19-35 years) were included. In both gropus body mass index (BMI) was calculated and waist circumference (WC) was measured. Hair cortisol, total serum testosterone (TT), serum cortisol, 25 OH vitamin D (25OHD), insulin, high sensitivity C-reactive protein (hsCRP), triglycerides (TG), HDL cholesterol (HDL), glucose and leptin were measured. Bioavailable testosterone (bioT) was calculated. Hair cortisol concentration was higher and significantly different in PCOS patients compared to the control group (130 vs 63 pg/mg of hair, p < 0.001). Subsequently, patients with PCOS were divided into two groups according to hair cortisol levels: group 1 with normal hair cortisol concentration and group 2 with levels above the upper limit of the reference values (128 pg/mg of hair). In group 2, TT significantly correlated with 25OHD, hsCRP, TG/HDL index, BMI, WC, insulin and HOMA (p < 0.05); bioT correlated with hsCRP and leptin (p < 0.05). Finally, 25OHD was inversely correlated with leptin and with TG/HDL index (p < 0.05). High hair cortisol concentration in patients with PCOS confirmed hyperactivation of the HPA axis. The associations observed were only found in patients with PCOS with high hair cortisol levels (> 128 pg/mg of hair), showing a possible effect of HPA axis in these associations.


Asunto(s)
Cabello , Hidrocortisona , Síndrome del Ovario Poliquístico , Adolescente , Adulto , Índice de Masa Corporal , Proteína C-Reactiva/metabolismo , Femenino , Cabello/química , Humanos , Hidrocortisona/análisis , Sistema Hipotálamo-Hipofisario/metabolismo , Insulina , Resistencia a la Insulina , Leptina/metabolismo , Obesidad/complicaciones , Sistema Hipófiso-Suprarrenal/metabolismo , Síndrome del Ovario Poliquístico/metabolismo , Testosterona , Adulto Joven
15.
Mol Ecol ; 20(13): 2739-55, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21627704

RESUMEN

Wild and cultivated plants represent very different habitats for pathogens, especially when cultivated plants bear qualitative resistance genes. Here, we investigated to what extent the population genetic structure of a plant pathogenic fungus collected on its wild host can be impacted by the deployment of resistant cultivars. We studied one of the main poplar diseases, poplar rust, caused by the fungus Melampsora larici-populina. A thousand and fifty individuals sampled from several locations in France were phenotyped for their virulence profile (ability to infect or not the most deployed resistant cultivar 'Beaupré'), and a subset of these was genotyped using 25 microsatellite markers. Bayesian assignment tests on genetic data clustered the 476 genotyped individuals into three genetic groups. Group 1 gathered most virulent individuals and displayed evidence for selection and drastic demographic changes resulting from breakdown of the poplar cultivar 'Beaupré'. Group 2 comprised individuals corresponding to ancestral populations of M. larici-populina naturally occurring in the native range. Group 3 displayed the hallmarks of strict asexual reproduction, which has never previously been demonstrated in this species. We discuss how poplar cultivation has influenced the spatial and genetic structure of this plant pathogenic fungus, and has led to the spread of virulence alleles (gene swamping) in M. larici-populina populations evolving on the wild host.


Asunto(s)
Basidiomycota/genética , Estructuras Genéticas/genética , Enfermedades de las Plantas/microbiología , Populus/microbiología , Alelos , Basidiomycota/aislamiento & purificación , Basidiomycota/patogenicidad , Teorema de Bayes , Cruzamiento , Análisis por Conglomerados , Demografía , Francia , Flujo Génico , Variación Genética , Genética de Población , Genotipo , Repeticiones de Microsatélite/genética , Mutación , Fenotipo , Virulencia/genética
16.
Opt Lett ; 36(13): 2486-8, 2011 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-21725453

RESUMEN

We demonstrate controlled high-order harmonic generation in gas using high-energy femtosecond pulses (50 fs-50 mJ on target) by performing spatial shaping of the terrawatt fundamental laser beam. We have developed a two optical paths mirror that can withstand high power and shape the pump beam into a quasi-flat-top profile (super Gaussian) near focus. We observe clear signatures of the spatial shaping on the harmonic beam in terms of profile, divergence, level of signal, and spectrum. The harmonic generation in neon with a quasi-flat-top beam results in a broadband extreme UV beam with extremely low divergence (~340 µrad).

17.
Opt Lett ; 36(17): 3386-8, 2011 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-21886219

RESUMEN

We characterize the phase shift induced by reflection on a multilayer mirror in the extreme UV range (80-93 eV) using two techniques: one based on high order harmonic generation and attosecond metrology (reconstruction of attosecond beating by interference of two-photon transitions), and a second based on synchrotron radiation and measurements of standing waves (total electron yield). We find an excellent agreement between the results from the two measurements and a flat group delay shift (±40 as) over the main reflectivity peak of the mirror.

18.
Phys Rev Lett ; 104(21): 213601, 2010 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-20867095

RESUMEN

We perform high harmonic generation spectroscopy of aligned nitrogen molecules to characterize the attosecond dynamics of multielectron rearrangement during strong-field ionization. We use the spectrum and ellipticity of the harmonic light to reconstruct the relative phase between different ionization continua participating in the ionization, and thus determine the shape and location of the hole left in the molecule by strong-field ionization. Our interferometric technique uses transitions between the ionic states, induced by the laser field on the subcycle time scale.

19.
Rev Sci Instrum ; 91(11): 113104, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-33261435

RESUMEN

We report the in-house fabrication of a high-resolution Fourier-transform spectrometer (FTS) for the spectroscopy of molecules in the gas phase at resolutions down to 0.002 cm-1 working in the spectral range from 5880 cm-1 (1.7 µm) to 15 380 cm-1 (650 nm). The FTS employs a supercontinuum as a broadband light source and a He:Ne laser with a homemade frequency-stabilization scheme as the spatial reference for the sampling of the interferogram on a constant optical path difference (OPD) grid. The sampling of the two lasers is performed at constant time intervals, and the resampling process is performed at the software level. The resampling of the interferogram on a constant OPD grid relies on cubic approximations of the He:Ne interference pattern to determine its zero-crossings. The use of an invariant in the sampling process allows us to perform on-the-fly data treatment. Both the hardware aspect and the data processing are described with, in each case, an original approach. We also report the successful coupling of the FTS with a high finesse optical cavity with effective mirror reflectivities of 99.76%, allowing us to reach sensitivities down to 6.5 × 10-8 cm-1 with a root-mean-square accuracy of 0.0017 cm-1 on the position of the Doppler-broadened transitions with a mean transition width of 0.046 cm-1 for spectra recorded at a spectral resolution of 0.015 cm-1. The sensitivity of the instrument per spectral element, once normalized, represents the best sensitivity reported in the literature for Fourier-transform incoherent broadband cavity-enhanced absorption spectroscopy with a supercontinuum light source.

20.
Cytometry A ; 75(9): 743-51, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19582873

RESUMEN

Analysis of the T-cell receptor (TCR) repertoire by flow cytometry proved to be relevant for investigating T-cell diversity and detecting reactive cells in blood samples. We used this approach to characterize non-malignant T-lymphocytes in lymph nodes and give insights into their origin. The TCR repertoire of CD4+ and CD8+ T-cells from 81 lymph nodes was analyzed with a four-color flow cytometer using a wide panel of 25 anti-Vbeta monoclonal antibodies. Flow cytometry proved to be a useful and informative technique. We demonstrated a diversified TCR-Vbeta repertoire, and only low level expansions, in 53% of the samples. They involved nearly all Vbeta families, were more frequent in the CD8+ subset of older patients, but were not related to pathology. No evidence could be demonstrated in favor of stimulation by common antigens. Interestingly, the TCR-Vbeta repertoire proved to be very similar in lymph nodes and blood samples. Our results argue that in the cases studied, lymph node enlargement is mainly due to an increased homing of circulating T-cells. They also provide reference values for expression of 25 TCR-Vbeta in lymph nodes, which could serve as a basis for further applications in diagnosis of T-cell lymphoproliferative disorders.


Asunto(s)
Citometría de Flujo/métodos , Inmunofenotipificación/métodos , Ganglios Linfáticos/patología , Receptores de Antígenos de Linfocitos T alfa-beta/sangre , Adenocarcinoma/inmunología , Adenocarcinoma/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/patología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Niño , Femenino , Enfermedad de Hodgkin/inmunología , Enfermedad de Hodgkin/patología , Humanos , Ganglios Linfáticos/inmunología , Linfoma de Células B/inmunología , Linfoma de Células B/patología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Seudolinfoma/inmunología , Seudolinfoma/patología , Valores de Referencia , Adulto Joven
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