67 research outputs found
Binary Galaxies in the Local Supercluster and Its Neighborhood
We report a catalog of 509 pairs identified among 10403 nearby galaxies with
line-of-sight velocities V_LG < 3500 km/s.We selected binary systems in
accordance with two criteria (bounding and temporal), which require the
physical pair of galaxies to have negative total energy and its components to
be located inside the zero-velocity surface. We assume that individual galaxy
masses are proportional to their total K-band luminosities, M = L_K x 6M/L. The
catalog gives the magnitudes and morphological types of galaxies and also the
projected (orbital) masses and pair isolation indices. The component
line-of-sight velocity differences and projected distances of the binary
systems considered have power-law distributions with the median values of 35
km/s and 123 kpc, respectively. The median mass-to-K-band luminosity ratio is
equal to 11 M/L, and its uncertainty is mostly due to the errors of measured
velocities. Our sample of binary systems has a typical density contrast of d
ro/ro_c ~ 500 and a median crossing time of about 3.5 Gyr. We point out the
substantial fraction of binary systems consisting of late-type dwarf galaxies,
where the luminosities of both components are lower than that of the Small
Magellanic Cloud. The median projected distance for 41 such pairs is only 30
kpc, and the median difference of their line-of-sight velocities is equal to 14
km/s which is smaller than the typical error for radial-velocity (30 km/s).
This specific population of gas-rich dwarf binary galaxies such as I Zw 18 may
be at the stage immediately before merging of its components. Such objects,
which are usually lost in flux-limited (and not distance-limited) samples
deserve a thorough study in the HI radio line with high spatial and velocity
resolution.Comment: published in Astrophysical Bulletin, 2008, Vol. 63, No. 4, pp.
299-34
Modelo de análise de regressão periódica da precipitação mensal, da bacia atlântico sudeste, no Estado do Paraná
Graphene Growth on Electroformed Copper Substrates by Atmospheric Pressure CVD
Chemical vapor deposition (CVD) is regarded as the most promising technique for the mass production of graphene. CVD synthesis under vacuum is the most employed process, because the slower kinetics give better control on the graphene quality, but the requirement for high-vacuum equipment heavily affects the overall energy cost. In this work, we explore the possibility of using electroformed Cu substrate as a catalyst for atmospheric-pressure graphene growth. Electrochemical processes can produce high purity, freestanding metallic films, avoiding the surface defects that characterize the rolled foils. It was found that the growth mode of graphene on the electroformed catalyst was related to the surface morphology, which, in turn, was affected by the preliminary treatment of the substrate material. Suitable conditions for growing single layer graphene were identified
The temporo-parietal fascial flap in extended transnasal endoscopic procedures: cadaver dissection and personal clinical experience.
Due to progressively expanded indications of endoscopic transnasal surgery, having different reconstructive options in the armamentarium becomes of paramount importance. We herein report our experience with the use of the temporo-parietal fascial flap after extended endoscopic procedures for malignancies of the clival and nasopharyngeal regions. We focus our report on the surgical anatomy of this flap and the technique for its intranasal transposition through an infratemporal corridor. The main steps of the procedure and anatomic landmarks were highlighted, thanks to previous cadaver dissection. Five patients underwent an extended endoscopic resection for malignant tumors: one with persistent clival chordoma, three with recurrent nasopharyngeal carcinomas, and 1 recurrent nasopharyngeal adenoid cystic carcinoma. In all patients a temporo-parietal fascial flap was harvested to protect critical structures or irradiated denuded bone. The Mean harvesting and hospitalization time were 120 min and 5 days, respectively. No major or minor complications were observed. Whenever local flaps are not available for oncologic reasons or previous surgery, the temporo-parietal fascial flap is a safe and relatively easy option to protect the residual skull base and critical structures such as the internal carotid artery and dura of the posterior cranial fossa, after extended endoscopic resections
Il lembo libero di retto dell'addome perforato (RAP) nella ricostruzione dei difetti della testa e del collo.
HART AND MYCOBACTERIUM AVIUM COMPLEX IN A HIV INFECTED PATIENT WITH SEVERE FACTOR VII DEFICIENCY
A clinical syndrome represented by the association of Mycobacterium avium complex (MAC) infection with initiation of highly active antiretroviral therapy (HAART) has been recently described in patients with advanced HIV disease. HAART-associated improvement of the immune status might convert a clinically silent MAC infection into an active mycobacterial disease. A 40-year-old man with severe factor VII deficiency, advanced HIV-1 disease, a CD4 + lymphocyte count of 15 cells microL-1 (CDC stage A3) and 470,000 HIV-RNA copies mL-1 (measurement by NASBA system) underwent standard HAART (lamivudine, stavudine and ritonavir). Two weeks after HAART onset, the patient developed enlargement of the lymph nodes throughout the mesentery and after seven weeks a rapidly enlarging mass on the left side of the neck. Culture from a needle aspirate specimen revealed MAC. His CD4 + count had increased to 97 cells microL-1 and viraemia dropped to undetectable HIV-RNA copies. While continuing antiviral therapy, multidrug therapy for MAC infection (clarithromycin, ciprofloxacin, ethambutol, amikacin) was started with progressive improvement and cure of the neck mycobacterial infection and disappearance of the abdominal lymph nodes. HAART has been shown to offer significant clinical and laboratory benefits in terms of HIV disease with limited side-effects in Haemophiliacs. However, the clinical manifestation of an opportunistic infection should be mentioned as a possible complication of HAART in these patients, as well as in other categories of HIV infected patients, and in patients with congenital coagulopathies
La ricostruzione dei difetti oncologici del massiccio facciale e del basicranio: esperienza di 136 casi
La ricostruzione dei difetti oncologici del massiccio facciale e del basicranio: esperienza di 136 casi.
Extramedullary hematopoiesis: a rare occurrence in the sinonasal tract.
none5noneBizzoni A; Lombardi D; MAROLDI, Roberto; Incardona P; NICOLAI, PieroBizzoni, A; Lombardi, D; Maroldi, Roberto; Incardona, P; Nicolai, Pier
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