2,377 research outputs found
A high resolution study of complex organic molecules in hot cores
We present the results of a line identification analysis using data from the
IRAM Plateau de Bure Inferferometer, focusing on six massive star-forming hot
cores: G31.41+0.31, G29.96-0.02, G19.61-0.23, G10.62-0.38, G24.78+0.08A1 and
G24.78+0.08A2. We identify several transitions of vibrationally excited methyl
formate (HCOOCH) for the first time in these objects as well as transitions
of other complex molecules, including ethyl cyanide (CHCN), and
isocyanic acid (HNCO). We also postulate a detection of one transition of
glycolaldehyde (CH(OH)CHO) in two new hot cores. We find G29.96-0.02,
G19.61-0.23, G24.78+0.08A1 and 24.78+0.08A2 to be chemically very similar.
G31.41+0.31, however, is chemically different: it manifests a larger chemical
inventory and has significantly larger column densities. We suggest that it may
represent a different evolutionary stage to the other hot cores in the sample,
or it may surround a star with a higher mass. We derive column densities for
methyl formate in G31.41+0.31, using the rotation diagram method, of
10 cm and a T of 170 K. For G29.96-0.02,
G24.78+0.08A1 and G24.78+0.08A2, glycolaldehyde, methyl formate and methyl
cyanide all seem to trace the same material and peak at roughly the same
position towards the dust emission peak. For G31.41+0.31, however,
glycolaldehyde shows a different distribution to methyl formate and methyl
cyanide and seems to trace the densest, most compact inner part of hot cores.Comment: Accepted to MNRA
Le relazioni sino-russe e il caso dell'Organizzazione per la cooperazione di Shangai
In uno scenario internazionale in cui le risorse di potere a disposizione dei vari attori sono in via di definizione e dove le dinamiche economiche paiono prevalere nel ridisegnare nuovi scenari ed equilibri, sia la Russia che la Cina si sono affermate come potenze centrali. La Cina, seppure contagiata dalla crisi ha saputo reagire e tornare a crescere in maniera più consistente e più celermente dei paesi del G-8 o degli altri BRIC e si consolida come la terza più grande economia del mondo
Winds as the origin of radio emission in radio-quiet extremely red quasars
Most active galactic nuclei (AGNs) are radio-quiet, and the origin of their
radio emission is not well-understood. One hypothesis is that this radio
emission is a by-product of quasar-driven winds. In this paper, we present the
radio properties of 108 extremely red quasars (ERQs) at . ERQs are among
the most luminous quasars ( erg/s) in the Universe,
with signatures of extreme ( km/s) outflows in their
[OIII]5007 \AA\ emission, making them the best subjects to seek the
connection between radio and outflow activity. All ERQs but one are unresolved
in the radio on kpc scales, and the median radio luminosity of ERQs
is erg/s, in the radio-quiet regime, but
one to two orders of magnitude higher than that of other quasar samples. The
radio spectra are steep, with a mean spectral index . In addition, ERQs neatly follow the extrapolation of the low-redshift
correlation between radio luminosity and the velocity dispersion of
[OIII]-emitting ionized gas. Uncollimated winds, with a power of one per cent
of the bolometric luminosity, can account for all these observations. Such
winds would interact with and shock the gas around the quasar and in the host
galaxy, resulting in acceleration of relativistic particles and the consequent
synchrotron emission observed in the radio. Our observations support the
picture in which ERQs are signposts of extremely powerful episodes of quasar
feedback, and quasar-driven winds as a contributor of the radio emission in the
intermediate regime of radio luminosity erg/s.Comment: accepted by MNRA
Direct Oral Anticoagulants and Their Use in Treatment and Secondary Prevention of Acute Symptomatic Venous Thromboembolism.
Direct oral anticoagulants (DOACs) have been compared with standard therapy in large phase III studies to assess their safety and efficacy in the treatment of deep vein thrombosis and/or pulmonary embolism and in the secondary prevention of recurrent venous thromboembolism. Although the mean population age and the gross inclusion and exclusion criteria were similar across these studies, they differed in other aspects such as overall study design and acute treatment strategies. The 4 DOACs examined in phase III trials (apixaban, edoxaban, rivaroxaban, and dabigatran) showed noninferiority compared with standard therapy for the treatment of deep vein thrombosis and/or pulmonary embolism and for the prevention of recurrent venous thromboembolism. Furthermore, these DOACs exhibited a similar safety profile to standard therapy, with the risk of major bleeding significantly reduced in some of these studies. Rivaroxaban and apixaban were tested as a single-drug approach, whereas in the dabigatran and edoxaban studies, initial bridging with parenteral agents was employed. The purpose of this review is to compare the phase III studies of DOACs in this indication, to highlight the differences, and to discuss a series of clinically relevant issues, including the management of key patient subgroups (eg, fragile patients, those with cancer or renal impairment), extended treatment, use of comedications, heparin pretreatment versus a single-drug approach, and the bleeding profiles of the DOACs
Percolation transition and distribution of connected components in generalized random network ensembles
In this work, we study the percolation transition and large deviation
properties of generalized canonical network ensembles. This new type of random
networks might have a very rich complex structure, including high heterogeneous
degree sequences, non-trivial community structure or specific spatial
dependence of the link probability for networks embedded in a metric space. We
find the cluster distribution of the networks in these ensembles by mapping the
problem to a fully connected Potts model with heterogeneous couplings. We show
that the nature of the Potts model phase transition, linked to the birth of a
giant component, has a crossover from second to first order when the number of
critical colors in all the networks under study. These results shed
light on the properties of dynamical processes defined on these network
ensembles.Comment: 27 pages, 15 figure
Non-local density correlations as signal of Hawking radiation in BEC acoustic black holes
We have used the analogy between gravitational systems and non-homogeneous
fluid flows to calculate the density-density correlation function of an atomic
Bose-Einstein condensate in the presence of an acoustic black hole. The
emission of correlated pairs of phonons by Hawking-like process results into a
peculiar long-range density correlation. Quantitative estimations of the effect
are provided for realistic experimental configurations.Comment: Strongly revised version. 5 pages, 3 eps figure
Discovery of a New Class of 1-(4-Sulfamoylbenzoyl)piperidine-4-carboxamides as Human Carbonic Anhydrase Inhibitors
A series of 1-(4-sulfamoylbenzoyl)piperidine-4-carboxamides deriving from substituted piperazines/benzylamines was designed, synthesized, and tested on human carbonic anhydrase (hCA). The inhibitory activity of the new sulfonamides was analyzed using acetazolamide (AAZ) as a standard inhibitor against hCA I, II, IX, and XII. Several sulfonamides showed both inhibitory activity at low nanomolar concentrations and selectivity against the cytosolic hCA II isoform, and the same trend was observed on the tumor-associated hCA IX and XII. The benzenesulfonamido carboxamides 11 and 15 were the most potent of the piperazino- and benzylamino-based series, respectively. Docking and molecular dynamics studies related the high selectivity of compound 11 toward the tumor-associated hCA isoforms to its capability to participate in favorable interactions within hCA IX and hCA XII active sites, whereas no such interactions were detected within both hCA I and hCA II isoforms
Detection of solar-like oscillations in the G5 subgiant mu-Herculis
A clear detection of excess of power, providing a substantial evidence for
solar-like oscillations in the G5 subgiant \muher{}, is presented. This star
was observed over seven nights with the SARG echelle spectrograph operating
with the 3.6-m Italian TNG Telescope, using an iodine absorption cell as a
velocity reference. A clear excess of power centered at 1.2 mHz, with peak
amplitudes of about 0.9 \ms in the amplitude spectrum is present. Fitting the
asymptotic relation to the power spectrum, a mode identification for the
modes in the frequency range 900-1600 \muHz is derived. The
most likely value for the large separation turns out to be 56.5 \muHz,
consistent with theoretical expectations. The mean amplitude per mode ()
at peak power results to be , almost three times larger than
the solar one.Comment: 8 pages, 6 figures, ApJ to appea
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