193 research outputs found
Monoamine oxidase (MAO) inhibitory effects of candidate MAO inhibitors found in cigarette smoke.
There is strong evidence that tobacco smoke inhibits both MAO A and MAO B isoforms in the body. However, which components of cigarette smoke are responsible for MAO inhibition is not clear yet. Our group has identified six previously unidentified candidate MAO inhibitors from the tobacco smoke. The MAO inhibitory effects of these candidate inhibitors were compared with that of nicotine and TPM (Tobacco Particulate Matter). An SH-SY5Y cell line was exposed to different regimens of ethanol (control), nicotine, TPM and the cocktail of candidate inhibitors. A final concentration 0.2 μM nicotine was used and the concentration of each candidate inhibitor was relative to that originally found in TPM. We found that nicotine did not have any significant MAO inhibitory effect compared to the control. TPM inhibited overall MAO activity by 39%, while the MAO inhibition by cocktail of candidate inhibitors was 47%. The results suggest that the candidate inhibitors identified by our group are the major contributors to the total MAO inhibitory activity depicted by cigarette smoke and potentially unlocks the mystery behind the components responsible for MAO inhibition by cigarette smoke in smokers
Signature of structural distortion in optical spectra of YFe2O4 thin film
We report structural, optical, and electro-optical properties of polycrystalline YFe2O4 thin films, deposited on (0001) sapphire substrates using the electron-beam deposition technique. The optical spectra of a 120 nm YFe2O4 show Fe d to d on-site and O 2p to Fe 3d, Y 4d, and Y 5s charge-transfer electronic excitations. Anomalies in the temperature dependence data of the charge-transfer excitations and the splitting of the 4.46 eV charge-transfer peak strongly suggest a structural distortion at 180 ± 10 K. Evidence of such a structural distortion is also manifested in the surface resistance versus temperature data. In addition, the YFe2O4 thin film at low temperatures shows strong electro-optical properties, as high as 9% in the energy range of 1 - 2.5 eV, for applied electric fields up to 500 V.cm−1
The Atacama Cosmology Telescope: The polarization-sensitive ACTPol instrument
The Atacama Cosmology Telescope (ACT) is designed to make high angular
resolution measurements of anisotropies in the Cosmic Microwave Background
(CMB) at millimeter wavelengths. We describe ACTPol, an upgraded receiver for
ACT, which uses feedhorn-coupled, polarization-sensitive detector arrays, a 3
degree field of view, 100 mK cryogenics with continuous cooling, and meta
material anti-reflection coatings. ACTPol comprises three arrays with separate
cryogenic optics: two arrays at a central frequency of 148 GHz and one array
operating simultaneously at both 97 GHz and 148 GHz. The combined instrument
sensitivity, angular resolution, and sky coverage are optimized for measuring
angular power spectra, clusters via the thermal Sunyaev-Zel'dovich and kinetic
Sunyaev-Zel'dovich signals, and CMB lensing due to large scale structure. The
receiver was commissioned with its first 148 GHz array in 2013, observed with
both 148 GHz arrays in 2014, and has recently completed its first full season
of operations with the full suite of three arrays. This paper provides an
overview of the design and initial performance of the receiver and related
systems
Development of the SPECULOOS exoplanet search project
SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) aims to
perform a transit search on the nearest (pc) ultracool (K) dwarf
stars. The project's main motivation is to discover potentially habitable
planets well-suited for detailed atmospheric characterisation with upcoming
giant telescopes, like the James Webb Space Telescope (JWST) and European Large
Telescope (ELT). The project is based on a network of 1m robotic telescopes,
namely the four ones of the SPECULOOS-Southern Observatory (SSO) in Cerro
Paranal, Chile, one telescope of the SPECULOOS-Northern Observatory (SNO) in
Tenerife, and the SAINT-Ex telescope in San Pedro M\'artir, Mexico. The
prototype survey of the SPECULOOS project on the 60~cm TRAPPIST telescope
(Chile) discovered the TRAPPIST-1 system, composed of seven temperate
Earth-sized planets orbiting a nearby (12~pc) Jupiter-sized star. In this
paper, we review the current status of SPECULOOS, its first results, the plans
for its development, and its connection to the Transiting Exoplanet Survey
Satellite (TESS) and JWST
Body mass index and circulating oestrone sulphate in women treated with adjuvant letrozole
Background: Obesity is an independent adverse prognostic factor in early breast cancer patients, but it is still controversial whether obesity may affect adjuvant endocrine therapy efficacy. The aim of our study (ancillary to the two clinical trials Gruppo Italiano Mammella (GIM)4 and GIM5) was to investigate whether the circulating oestrogen levels during treatment with the aromatase inhibitor letrozole are related to body mass index (BMI) in postmenopausal women with breast cancer. Methods: Plasma concentration of oestrone sulphate (ES) was evaluated by radioimmunoassay in 370 patients. Plasma samples were obtained after at least 6 weeks of letrozole therapy (steady-state time). Patients were divided into four groups according to BMI. Differences among the geometric means (by ANOVA and ANCOVA) and correlation (by Spearman's rho) between the ES levels and BMI were assessed. Results: Picomolar geometric mean values (95% confidence interval, n=patients) of circulating ES during letrozole were 58.6 (51.0-67.2, n=150) when BMI was <25.0 kg m-2; 65.6 (57.8-74.6, n=154) when 25.0-29.9 kg m-2; 59.3 (47.1-74.6, n=50) when 30.0-34.9 kg m -2; and 43.3 (23.0-81.7, n=16) when 6535.0 kg m-2. No statistically significant difference in terms of ES levels among groups and no correlation with BMI were observed. Conclusions: Body mass index does not seem to affect circulating oestrogen levels in letrozole-treated patient
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