To study the metabolism of thyrotropin-releasing hormone (TRH) in vivo, 400 mug TRH was administered intravenously to eight normal male subjects. Multiple plasma and urine samples were obtained ...before and after TRH administration. Serum TSH concentrations increased after TRH administration in all subjects. Plasma TRH levels, measured by radioimmunoassay, were undetectable (< 0.4 ng/ml) before TRH administration. Plasma TRH concentrations averaged 33+/-7 ng/ml (mean +/-SEM) 2 min after TRH injection. Thereafter, they decreased rapidly so that the mean plasma TRH level was 2.9 ng/ml 20 min after TRH administration. The fall in plasma TRH levels was linear during this interval. Thereafter TRH levels declined more slowly. The mean half-life (t(1/2)) of TRH was 5.3+/-0.5 min. The mean distribution volume was 15.7+/-3.8 liters, an average of 16.5% of body weight in these subjects. In the urine, 5.5+/-0.9% of the administered TRH was recovered in the 3 h after TRH administration. Of the total urinary TRH recovered, 84.9% was excreted in the first 30 min. These results indicate that TRH is distributed in a large volume, that it is rapidly metabolized and that a significant quantity of administered TRH is excreted in the urine.
The regional distribution of thyrotropin-releasing hormone (TRH) in rat brain was studied. The greatest concentration of TRH was found in the median eminence. High concentrations were also found in ...several hypothalamic nuclei. Outside the hypothalamus, relatively large amounts of TRH were found in the septal and preoptic areas.
Class. Quantum Grav. 38 (2021) 195021 We report on the development and extensive characterization of co-sputtered
tantala-zirconia thin films, with the goal to decrease coating Brownian noise
in ...present and future gravitational-wave detectors. We tested a variety of
sputtering processes of different energies and deposition rates, and we
considered the effect of different values of cation ratio $\eta =$ Zr/(Zr+Ta)
and of post-deposition heat treatment temperature $T_a$ on the optical and
mechanical properties of the films. Co-sputtered zirconia proved to be an
efficient way to frustrate crystallization in tantala thin films, allowing for
a substantial increase of the maximum annealing temperature and hence for a
decrease of coating mechanical loss. The lowest average coating loss was
observed for an ion-beam sputtered sample with $\eta = 0.485 \pm 0.004$
annealed at 800 $^{\circ}$C, yielding $\overline{\varphi} = 1.8 \times
10^{-4}$. All coating samples showed cracks after annealing. Although in
principle our measurements are sensitive to such defects, we found no evidence
that our results were affected. The issue could be solved, at least for
ion-beam sputtered coatings, by decreasing heating and cooling rates down to 7
$^{\circ}$C/h. While we observed as little optical absorption as in the
coatings of current gravitational-wave interferometers (0.5 parts per million),
further development will be needed to decrease light scattering and avoid the
formation of defects upon annealing.
We report on the development and extensive characterization of co-sputtered tantala-zirconia thin films, with the goal to decrease coating Brownian noise in present and future gravitational-wave ...detectors. We tested a variety of sputtering processes of different energies and deposition rates, and we considered the effect of different values of cation ratio \(\eta =\) Zr/(Zr+Ta) and of post-deposition heat treatment temperature \(T_a\) on the optical and mechanical properties of the films. Co-sputtered zirconia proved to be an efficient way to frustrate crystallization in tantala thin films, allowing for a substantial increase of the maximum annealing temperature and hence for a decrease of coating mechanical loss. The lowest average coating loss was observed for an ion-beam sputtered sample with \(\eta = 0.485 \pm 0.004\) annealed at 800 \(^{\circ}\)C, yielding \(\overline{\varphi} = 1.8 \times 10^{-4}\). All coating samples showed cracks after annealing. Although in principle our measurements are sensitive to such defects, we found no evidence that our results were affected. The issue could be solved, at least for ion-beam sputtered coatings, by decreasing heating and cooling rates down to 7 \(^{\circ}\)C/h. While we observed as little optical absorption as in the coatings of current gravitational-wave interferometers (0.5 parts per million), further development will be needed to decrease light scattering and avoid the formation of defects upon annealing.
We present results of a search for continuously-emitted gravitational radiation, directed at the brightest low-mass X-ray binary, Scorpius X-1. Our semi-coherent analysis covers 10 days of LIGO S5 ...data ranging from 50-550 Hz, and performs an incoherent sum of coherent $\mathcal{F}$-statistic power distributed amongst frequency-modulated orbital sidebands. All candidates not removed at the veto stage were found to be consistent with noise at a 1% false alarm rate. We present Bayesian 95% confidence upper limits on gravitational-wave strain amplitude using two different prior distributions: a standard one, with no a priori assumptions about the orientation of Scorpius X-1; and an angle-restricted one, using a prior derived from electromagnetic observations. Median strain upper limits of 1.3e-24 and 8e-25 are reported at 150 Hz for the standard and angle-restricted searches respectively. This proof of principle analysis was limited to a short observation time by unknown effects of accretion on the intrinsic spin frequency of the neutron star, but improves upon previous upper limits by factors of ~1.4 for the standard, and 2.3 for the angle-restricted search at the sensitive region of the detector.
In this paper we report on a search for short-duration gravitational wave bursts in the frequency range 64 Hz-1792 Hz associated with gamma-ray bursts (GRBs), using data from GEO600 and one of the ...LIGO or Virgo detectors. We introduce the method of a linear search grid to analyse GRB events with large sky localisation uncertainties such as the localisations provided by the Fermi Gamma-ray Burst Monitor (GBM). Coherent searches for gravitational waves (GWs) can be computationally intensive when the GRB sky position is not well-localised, due to the corrections required for the difference in arrival time between detectors. Using a linear search grid we are able to reduce the computational cost of the analysis by a factor of O(10) for GBM events. Furthermore, we demonstrate that our analysis pipeline can improve upon the sky localisation of GRBs detected by the GBM, if a high-frequency GW signal is observed in coincidence. We use the linear search grid method in a search for GWs associated with 129 GRBs observed satellite-based gamma-ray experiments between 2006 and 2011. The GRBs in our sample had not been previously analysed for GW counterparts. A fraction of our GRB events are analysed using data from GEO600 while the detector was using squeezed-light states to improve its sensitivity; this is the first search for GWs using data from a squeezed-light interferometric observatory. We find no evidence for GW signals, either with any individual GRB in this sample or with the population as a whole. For each GRB we place lower bounds on the distance to the progenitor, assuming a fixed GW emission energy of $10^{-2} M_{\odot}c^{2}$, with a median exclusion distance of 0.8 Mpc for emission at 500 Hz and 0.3 Mpc at 1 kHz. The reduced computational cost associated with a linear search grid will enable rapid searches for GWs associated with Fermi GBM events in the Advanced detector era.
Class.Quant.Grav.27:225020,2010 Thermal noise arising from mechanical dissipation in dielectric reflective
coatings is expected to critically limit the sensitivity of precision
measurement systems ...such as high-resolution optical spectroscopy, optical
frequency standards and future generations of interferometric gravitational
wave detectors. We present measurements of the effect of post-deposition heat
treatment on the temperature dependence of the mechanical dissipation in
ion-beam sputtered tantalum pentoxide between 11\,K and 300\,K. We find the
temperature dependence of the dissipation is strongly dependent on the
temperature at which the heat treatment was carried out, and we have identified
three dissipation peaks occurring at different heat treatment temperatures. At
temperatures below 200\,K, the magnitude of the loss was found to increase with
higher heat treatment temperatures, indicating that heat treatment is a
significant factor in determining the level of coating thermal noise.
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