Purpose
Serum-negative-chronic-autoimmune-thyroiditis (SN-CAT) is considered a milder variant of classic Hashimoto’s thyroiditis (CHT). However, its prevalence remains unknown and it is still unclear ...whether SN-CAT behaves differently in terms of
l
-thyroxine (LT4) substitution treatment of hypothyroidism. Aims of this study were to estimate the prevalence of SN-CAT in a large series of hypothyroid patients and to compare LT4 requirements in hypothyroid patients with SN-CAT and CHT.
Methods
Five-hundred-eighty-one consecutive patients with primary-autoimmune-hypothyroidism were enrolled in a cross-sectional study. LT4 requirements and thyroid-volume changes were longitudinally evaluated in 49 hypothyroid patients with SN-CAT and in 98 sex and age-matched hypothyroid patients with CHT.
Results
In our series the prevalence of SN-CAT was 20.8%. At diagnosis, patients in the CHT and SN-CAT groups had similar male/female ratio, age and BMI, while serum TSH and thyroid-volume were significantly greater in the CHT group. In the longitudinal study, during a follow-up of 8.9 ± 4.6 years, 8 out of 49 (16.3%) SN-CAT patients developed positive tests for of circulating TPO-Ab and/or Tg-Ab. Thyroid-volume significantly decreased in CHT patients, but not in those with SN-CAT. The maximum daily substitution dose of LT4 was smaller in SN-CAT patients as compared with the CHT ones. Multivariate analysis showed that age, BMI, basal TSH and thyroid antibody status independently and significantly predicted the maximum daily substitution dose of LT4.
Conclusions
SN-CAT accounts for a significant proportion of patients with autoimmune hypothyroidism. Compared with hypothyroid patients diagnosed with CHT, the SN-CAT ones require smaller doses of LT4 to correct their hypothyroidism.
We describe the BOOMERanG experiment and its main result, i.e. the measurement of the large scale curvature of the Universe. BOOMERanG is a balloon-borne microwave telescope with sensitive cryogenic ...detectors. BOOMERanG has measured the angular distribution of the Cosmic Microwave Background on ∼ 3% of the sky, with a resolution of ∼ 10 arcmin and a sensitivity of ∼ 20μ
K per pixel. The resulting image is dominated by hot and cold spots with rms fluctuations ∼ 80μ
K and typical size of ∼ 1
o. The detailed angular power spectrum of the image features three peaks and two dips at ℓ = (213
−13
+10), (541
−32
+20), (845
−25
+12) and ℓ = (416
−12
+22), (750
−750
+20), respectively. Such very characteristic spectrum can be explained assuming that the detected structures are the result of acoustic oscillations in the primeval plasma. In this framework, the measured pattern constrains the density parameter Ω to be 0.85 < Ω < 1.1 (95% confidence interval). Other cosmological parameters, like the spectral index of initial density fluctuations, the density parameter for baryons, dark matter and dark energy, are detected or constrained by the BOOMERanG measurements and by other recent CMB anisotropy experiments. When combined with other cosmological observations, these results depict a new, consistent, cosmological scenario.
A multipurpose 3He refrigerator Pizzo, L.; Dall’Oglio, G.; Martinis, L. ...
Cryogenics (Guildford),
10/2006, Letnik:
46, Številka:
10
Journal Article
Recenzirano
We introduce a mini
3He refrigerator, operating at ∼300
mK starting from 4.2
K without pumping on the main
4He bath. The innovative idea is that the present one is suitable for a very fast operation; ...for its use, it is sufficient a storage
4He Dewar. In this way we drastically reduce the time required to cool it down, because there is no need for a classic cryostat. This prototype is particularly aimed for all those operations in which it is necessary to test a large number of samples that do not require long duration measurements at low temperature.
We report on millimetric continuum observations of two bright compact HII regions, which have been observed for the first time in this frequency range. For the two observed regions (G291.6-0.5 and ...G291.3-0.7), we derive the flux densities at the two observed wavelengths (1.25 and 2 mm) as well as the spectral index and the temperature of the surrounding dust by fitting a modified blackbody curve to our results combined with IR values obtained from the literature. We also estimate the dust mass and the bolometric luminosity of the two regions.
The blackbody radiation left over from the Big Bang has been transformed by the expansion of the Universe into the nearly isotropic 2.73 K cosmic microwave background. Tiny inhomogeneities in the ...early Universe left their imprint on the microwave background in the form of small anisotropies in its temperature. These anisotropies contain information about basic cosmological parameters, particularly the total energy density and curvature of the Universe. Here we report the first images of resolved structure in the microwave background anisotropies over a significant part of the sky. Maps at four frequencies clearly distinguish the microwave background from foreground emission. We compute the angular power spectrum of the microwave background, and find a peak at Legendre multipole Ipeak = (197 +/- 6), with an amplitude delta T200 = (69 +/- 8) microK. This is consistent with that expected for cold dark matter models in a flat (euclidean) Universe, as favoured by standard inflationary models.
Recent results from BOOMERANG-98 and MAXIMA-1, taken together with COBE DMR, provide consistent and high signal-to-noise measurements of the cosmic microwave background power spectrum at spherical ...harmonic multipole bands over 2<l less similar to 800. Analysis of the combined data yields 68% (95%) confidence limits on the total density, Omega(tot) approximately 1.11+/-0.07 (+0.13)(-0.12), the baryon density, Omega(b)h(2) approximately 0.032(+0.005)(-0.004) (+0.009)(-0.008), and the scalar spectral tilt, n(s) approximately 1.01(+0.09)(-0.07) (+0.17)(-0.14). These data are consistent with inflationary initial conditions for structure formation. Taken together with other cosmological observations, they imply the existence of both nonbaryonic dark matter and dark energy in the Universe.
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