Synchrotron X-ray diffraction experiments with a prototype hybrid pixel detector

International audienceA prototype X-ray pixel area detector (XPAD3.1) has been used for X-ray diffraction experiments with synchrotron radiation. The characteristics of this detector are very attractive in terms of fast readout time, high dynamic range and high signal-to-noise ratio. The prototype XPAD3.1 enabled various diffraction experiments to be performed at different energies, sample-to-detector distances and detector angles with respect to the direct beam, yet it was necessary to perform corrections on the diffraction images according to the type of experiment. This paper is focused on calibration and correction procedures to obtain high-quality scientific results specifically developed in the context of three different experiments, namely mechanical characterization of nanostructured multilayers, elastic-plastic deformation of duplex steel and growth of carbon nanotubes

TRH: Pathophysiologic and clinical implications

Thyrotropin releasing hormone is thought to be a tonic stimulator of the pituitary TSH secretion regulating the setpoint of the thyrotrophs to the suppressive effect of thyroid hormones. The peptide stimulates the release of normal and elevated prolactin. ACTH and GH may increase in response to exogenous TRH in pituitary ACTH and GH hypersecretion syndromes and in some extrapituitary diseases. The pathophysiological implications of extrahypothalamic TRH in humans are essentially unknown. The TSH response to TRH is nowadays widely used as a diganostic amplifier in thyroid diseases being suppressed in borderline and overt hyperthyroid states and increased in primary thyroid failure. In hypothyroid states of hypothalamic origin, TSH increases in response to exogenous TRH often with a delayed and/or exaggerated time course. But in patients with pituitary tumors and suprasellar extension TSH may also respond to TRH despite secondary hypothyroidism. This TSH increase may indicate a suprasellar cause for the secondary hypothyroidism, probably due to portal vessel occlusion. The TSH released in these cases is shown to be biologically inactive

Hormone Treatment, Estrogen Receptor Polymorphisms and Mortality: A Prospective Cohort Study

International audienceBACKGROUND: The association between hormone treatment (HT) and mortality remains controversial. This study aimed to determine whether the risk of mortality associated with HT use varies depending on the specific characteristics of treatment and genetic variability in terms of the estrogen receptor. METHODOLOGY/PRINCIPAL FINDINGS: A prospective, population-based study of 5135 women aged 65 years and older who were recruited from three cities in France and followed over six years. Detailed information related to HT use was obtained and five estrogen receptor polymorphisms were genotyped. The total follow-up was 25,436 person-years and during this time 352 women died. Cancer (36.4%) and cardiovascular disease (19.3%) were the major causes of death. Cox proportional hazards models adjusted for age, education, centre, living situation, comorbidity, depression, physical and mental incapacities, indicated no significant association between HT and mortality, regardless of the type or duration of treatment, or the age at initiation. However, the association between HT and all-cause or cancer-related mortality varied across women, with significant interactions identified with three estrogen receptor polymorphisms (p-values = 0.004 to 0.03) in adjusted analyses. Women carrying the C allele of ESR1 rs2234693 had a decreased risk of all-cause mortality with HT (HR: 0.42, 95% CI: 0.18-0.97), while in stark contrast, those homozygous for the T allele had a significantly increased risk of cancer-related mortality (HR: 3.18, 95% CI: 1.23-8.20). The findings were similar for ESR1 rs9340799 and ESR2 rs1271572. CONCLUSIONS/SIGNIFICANCE: The risk of mortality was not associated with HT duration, type or age at initiation. It was however not equal across all women, with some women appearing genetically more vulnerable to the effects of HT in terms of their estrogen receptor genotype. These findings, if confirmed in another independent study, may help explain the differential susceptibility of women to the beneficial or adverse effects of HT

Nuevos resultados y recientes estudios sobre la fluencia del hormigón

Not availableLa memoria que presentan los autores no tiene por objeto proponer una teoría fisicoquímica de la fluencia. Se ha presentado ya un buen número de ellas para que se pueda añadir otra con suficiente certidumbre. El deseo de los autores es simplemente aportar hechos experimentales susceptibles de ser interpretados, pues los resultados que se dan se han obtenido con todas las precauciones necesarias para garantizar la objetividad. Debe señalarse, en primer lugar, que la fluencia se ha estudiado entre 5 y 10 años con un aumento débil pero cierto, al menos en atmósfera seca (50 % H.R.). La edad de carga tiene una influencia clara sobre la fluencia ulterior en atmósfera seca. La fluencia a 8 años disminuye siguiendo una ley aproximativa en A-B log t. Bajo agua, el efecto de la edad de carga es mucho menos importante. Juega su papel la dimensión absoluta de las piezas de ensayo: la fluencia disminuye en magnitud y en velocidad cuando la dimensión aumenta (del orden de 1/4 entre prismas de 7 y 20 cm de lado). La deformación de la fluencia bajo carga no va acompañada de una pérdida de agua medible superior a la que acompaña la retracción sin carga. La variación de humedad del medio de conservación entre dos valores a y h (100 y 50 % H.R.) da una fluencia media ligeramente inferior a la media de las fluencias bajo las higrometrías a y h. Es probable (aunque no está probado) que las deformaciones de la fluencia en compresión responden al principio de superposición de fuerzas, cuando éstas son inferiores al tercio de la carga de rotura. En los límites de dosificación de cemento de 250 a 400 kg/m3, la amplitud de la fluencia disminuye cuando esta dosificación aumenta

Le traitement de l'hypogonadisme hypogonadotrope par administration intermittente de lh-rh

SCOPUS: NotDefined.jinfo:eu-repo/semantics/publishe