860 research outputs found
Tromboendarterectomia Pulmonar em Portugal: Experiência Inicial
Introduction: Surgical treatment for chronic thromboembolic pulmonary hypertension (CTEPH) is challenging. Most Portuguese patients with CTEPH have been referred to foreign institutions for treatment, with significant social and economic costs. To meet this emerging need, the cardiothoracic surgery department of Hospital de Santa Marta, Lisbon, has developed a dedicated program for pulmonary thromboendarterectomy (PTE). We hereby present the results for the first 19 patients treated.
Methods: We conducted a retrospective analysis of all 19 patients who underwent PTE at Hospital de Santa Marta between 2008 and April 2019.
Results: Since 2008, a total of 19 patients have undergone PTE in our department. The procedure was performed with good outcomes in both survival and functional recovery. At the very beginning of the series two patients died perioperatively, before all the team underwent formal training at the Royal Papworth Hospital, UK, with no early deaths since. Postoperative complications were similar to other published series. During 11 years of follow-up, there were three late deaths, all in patients with residual pulmonary arterial hypertension. At the latest follow-up (October 2019), all surviving patients showed significant functional recovery, all in NYHA class I or II, with only one patient on vasodilator therapy with sildenafil (the first in the series, operated in 2008).
Conclusions: PTE is a demanding procedure, in which outcomes are related to volume and accumulated experience, however it can be performed safely and with reproducible results by a properly prepared dedicated team with a well-controlled learning curve. More patients and multidisciplinary experience will be needed to further improve and streamline results.info:eu-repo/semantics/publishedVersio
Light-Induced Atomic Desorption for loading a Sodium Magneto-Optical Trap
We report studies of photon-stimulated desorption (PSD), also known as
light-induced atomic desorption(LIAD), of sodium atoms from a vacuum cell glass
surface used for loading a magneto-optical trap (MOT). Fluorescence detection
was used to record the trapped atom number and the desorption rate. We observed
a steep wavelength dependence of the desorption process above 2.6 eV photon
energy, a result significant for estimations of sodium vapor density in the
lunar atmosphere. Our data fit well to a simple model for the loading of the
MOT dependent only on the sodium desorption rate and residual gas density. Up
to 3.7x10^7 Na atoms were confined under ultra-high vacuum conditions, creating
promising loading conditions for a vapor cell based atomic Bose-Einstein
condensate of sodium.Comment: Sodium LIAD loaded MOT, 7 pages, 5 figures. Revised submitted
manuscript with minor corrections, new data presented, Fig.5 change
A stratigraphic framework for the Miocene from the lower Tagus Basin (Lisbon, Setúbal Península, Portugal) Depositional sequences, biostratigraphy and isotopic ages
Rev. Soc. Geol. España, 12(1), ano 1999Lithostratigraphy, main biostratigraphic events (first and last ocurrence), 87Sr/86Sr as well
as KlAr isotopic ages, are presented for the Lower Tagus basin (LTB) Miocene (Lisboa and Peninsula
de Setubal regions). Eight depositional sequences (DS) delimited by regional disconformities related
with transgressive surfaces are defined. The main features of the Depositional Sequences are as follows:
Depositional sequence (DS) A (Aquitanian). Biostratigraphy (Biost.): Small mammals from Km 10:
MN2 (MN3?); ostracoda: Aquitanian fauna. Isotopic age (IA): glauconites (KlAr) values between 19
and 24 Ma. 87Sr/86Sr ages from the glauconite levels: 22.3 (+0.4-0.7) Ma. Lower and upper boundaries
not well established. DS BO (Lower Burdigalian). Biost.: foraminifera - Fa Globigerinoides
altiaperturus (NS); mammals - Fa Brachyodus intermedius (MN3); ostracoda - La Hemicyprideis
helvetica and Pokomyella lusitanica at the LTB. IA (87Sr/86Sr): Foz da Fonte -19.S (±0.2) Ma, Penedo
Sui (base) - 20.0(±0.4)Ma; Almada (top) - 18.3 (+0.-0.2) Ma. Mammal sites: Av. do Uruguai - 21.S( +O.S-
0.3) Ma; Univ. Cat6lica - 20.S (+0.3-0.2) Ma. DS Bl (Middle Burdigalian). Biost.: foraminifera -
Catapsydrax unicavus and Globigerinoides altiaperturus (N6); mammals - Fa Gomphotherium, La
of Brachyodus (MN4); ostracoda -La Ruggieria (R.) micheliniana, Cnestocythere truncata, Pokomiella
minor and Triebelina raripila. fA (87Sr/86Sr) Foz da Fonte - 19.7 (+0.3-0.2) to 18.S (+0.2-0.S) Ma. DS
B2 (Upper Burdigalian). Biost.: mammals -Fa Bunolistriodon and Megacricetodon primitivus (MN4);
ostracoda - La Miocyprideisfortisensis. IA (87Sr/86Sr): Penedo Norte 17.7 (+0.7-0.S) Ma; 17.8 (+0.7-
O.S) Ma. DS Ll (Upper Burdigalian and Langhian). Biost.: foraminifera - Fa Praeorbulina (N8);
mammals - Fa (upper part) Hispanotherium and Megacricetodon collongensis, La M. primitivus
(MNS); ostracoda - Fa Pterigocythereis (P.) siveteri and Loxoconcha (L.) ducasseae. IA (87Sr/86Sr):
Penedo Norte 17.3 (+0.6-0.5) Ma. DS SI (Upper Langhian and Serravallian). Biost.: foraminiferaFa
Orbulina suturalis, O. universa and Globorotalia cf. menardii; ostracoda -Fa Aurila (u.) oblonga,
Ruggieria (R.) nuda, R. tetraptera tetraptera, Nomurocythereis seminulum, Pterygocythereis (P.) jonesi
y Olinfalunia costata. IA (87Sr/86Sr): Chelas 14.7 (+ 1.S-0.S) Ma, Almada (Brielas ) (lower part) - 14.0
(±0.4 ) Ma, Penedo (upper part) 12.S (+ 1.0-2.0) Ma. DS S2? (Upper Serravallian) is poorly characterized
due to strong condensation (Foz da Fonte-Rib. Lage) and poor outcrops (Lisbon region). Biost.:
foraminifera - La Globigerinoides subquadratus (top). DS Tl (Tortonian). Biost.: foraminifera - La
Globorotalia mayeri (lower part), Fa Neogloboquadrina acostaensis (upper part); ostracoda - Fa
Aurila (U.) zbyszewskii, Celtia quadridentada and Cyheretta (C.) simplex. IA: Penedo Norte: KlAr-
1O.9S±0.2S Ma; 87Sr/86Sr - 11.3 (+ 1.7-2.8) Ma; Almada (Foz de Rego) - 8.3 (+ 1.9-3.3) Ma; Fonte da
Telha S.2 (+3.1-1.2) Ma
Thermal Emission from HII Galaxies: Discovering the Youngest Systems
We studied the radio properties of very young massive regions of star
formation in HII galaxies, with the aim of detecting episodes of recent star
formation in an early phase of evolution where the first supernovae start to
appear. Our sample consists of 31 HII galaxies, characterized by strong
Hydrogen emission lines, for which low resolution VLA 3.5cm and 6cm
observations were obtained. The radio spectral energy distribution has a range
of behaviours; 1) there are galaxies where the SED is characterized by a
synchrotron-type slope, 2) galaxies with a thermal slope, and, 3) galaxies with
possible free-free absorption at long wavelengths. The latter SEDs were found
in a few galaxies and represent a signature of heavily embedded massive star
clusters closely related to the early stages of massive star formation. Based
on the comparison of the star formation rates determined from the recombination
lines and those determined from the radio emission we find that SFR(Ha) is on
average five times higher than SFR(1.4GHz). We confirm this tendency by
comparing the ratio between the observed flux at 20 cm and the expected one,
calculated based on the Ha star formation rates, both for the galaxies in our
sample and for normal ones. This analysis shows that this ratio is a factor of
2 smaller in our galaxies than in normal ones, indicating that they fall below
the FIR/radio correlation. These results suggest that the emission of these
galaxies is dominated by a recent and massive star formation event in which the
first supernovae (SN) just started to explode. We conclude that the systematic
lack of synchrotron emission in those systems with the largest equivalent width
of Hb can only be explained if those are young starbursts of less than 3.5Myr
of age.Comment: Accepted for publication in Ap
On the feedback from super stellar clusters. I. The structure of giant HII regions and HII galaxies
We review the structural properties of giant extragalactic HII regions and
HII galaxies based on 2D hydrodynamic calculations, and propose an evolutionary
sequence that accounts for their observed detailed structure. The model assumes
a massive and young stellar cluster surrounded by a large collection of clouds.
These are thus exposed to the most important star-formation feedback
mechanisms: photoionization and the cluster wind. The models show how the two
feedback mechanisms compete in the disruption of clouds and lead to two
different hydrodynamic solutions: The storage of clouds into a long lasting
ragged shell that inhibits the expansion of the thermalized wind, and the
steady filtering of the shocked wind gas through channels carved within the
cloud stratum. Both solutions are claimed to be concurrently at work in giant
HII regions and HII galaxies, causing their detailed inner structure. This
includes multiple large-scale shells, filled with an X-ray emitting gas, that
evolve to finally merge with each other, giving the appearance of shells within
shells. The models also show how the inner filamentary structure of the giant
superbubbles is largely enhanced with matter ablated from clouds and how cloud
ablation proceeds within the original cloud stratum. The calculations point at
the initial contrast density between the cloud and the intercloud media as the
factor that defines which of the two feedback mechanisms becomes dominant
throughout the evolution. Animated version of the models can be found at
http://www.iaa.csic.es/\~{}eperez/ssc/ssc.html.Comment: 28 pages, 10 figures, accepted for publication in the ApJ. Animated
version of the models can be found at
http://www.iaa.csic.es/\~{}eperez/ssc/ssc.htm
Chemical Properties of Star-Forming Emission Line Galaxies at z=0.1 - 0.5
We measure oxygen and nitrogen abundances for 14 star-forming emission line
galaxies (ELGs) at 0.11<z<0.5 using Keck/LRIS optical spectroscopy. The targets
exhibit a range of metallicities from slightly metal-poor like the LMC to
super-solar. Oxygen abundances of the sample correlate strongly with rest-frame
blue luminosities. The metallicity-luminosity relation based on these 14
objects is indistinguishable from the one obeyed by local galaxies, although
there is marginal evidence (1.1sigma) that the sample is slightly more
metal-deficient than local galaxies of the same luminosity. The observed
galaxies exhibit smaller emission linewidths than local galaxies of similar
metallicity, but proper corrections for inclination angle and other systematic
effects are unknown. For 8 of the 14 objects we measure nitrogen-to-oxygen
ratios. Seven of 8 systems show evidence for secondary nitrogen production,
with log(N/O)> -1.4 like local spirals. These chemical properties are
inconsistent with unevolved objects undergoing a first burst of star formation.
The majority of the ELGs are presently ~4 magnitudes brighter and ~0.5 dex more
metal-rich than the bulk of the stars in well-known metal-poor dwarf
spheroidals such as NGC 205 and NGC 185, making an evolution between some ELGs
and metal-poor dwarf spheroidals improbable. However, the data are consistent
with the hypothesis that more luminous and metal-rich spheroidal galaxies like
NGC 3605 may become the evolutionary endpoints of some ELGs. [abridged]Comment: 41 pages, w/12 figures, uses AASTeX aaspp4.sty, psfig.sty; To appear
in The Astrophysical Journa
Sélaciens du Miocène terminal du bassin d'Alvalade (Portugal). Essai de synthèse
A rich uppermost Miocene selachian fauna from the Alvalade Basin (represented by more than 10.000 teeth) is accounted for. It is the most modern miocene fauna of neritic habit under warm-temperate to subtropical conditions, known in the european
Miocene
Pulmonary Artery Sarcoma Masquerading As Subchronic Pulmonary Thromboembolism
info:eu-repo/semantics/publishedVersio
Capturing Choline–Aromatics Cation−π Interactions in the MARTINI Force Field
Cation-πinteractions play an important role in biomolecular recognition, including interactions between membrane phosphatidylcholine lipids and aromatic amino acids of peripheral proteins. While molecular mechanics coarse grain (CG) force fields are particularly well suited to simulate membrane proteins in general, they are not parameterized to explicitly reproduce cation-πinteractions. We here propose a modification of the polarizable MARTINI coarse grain (CG) model enabling it to model membrane binding events of peripheral proteins whose aromatic amino acid interactions with choline headgroups are crucial for their membrane binding. For this purpose, we first collected and curated a dataset of eight peripheral proteins from different families. We find that the MARTINI CG model expectedly underestimates aromatics-choline interactions and is unable to reproduce membrane binding of the peripheral proteins in our dataset. Adjustments of the relevant interactions in the polarizable MARTINI force field yield significant improvements in the observed binding events. The orientation of each membrane-bound protein is comparable to reference data from all-atom simulations and experimental binding data. We also use negative controls to ensure that choline-aromatics interactions are not overestimated. We finally check that membrane properties, transmembrane proteins, and membrane translocation potential of mean force (PMF) of aromatic amino acid side-chain analogues are not affected by the new parameter set. This new version "MARTINI 2.3P" is a significant improvement over its predecessors and is suitable for modeling membrane proteins including peripheral membrane binding of peptides and proteins
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