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1.
Life Sci Space Res (Amst) ; 41: 210-217, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38670649

RESUMO

In addition to the continuous exposure to cosmic rays, astronauts in space are occasionally exposed to Solar Particle Events (SPE), which involve less energetic particles but can deliver much higher doses. The latter can exceed several Gy in a few hours for the most intense SPEs, for which non-stochastic effects are thus a major concern. To identify adequate shielding conditions that would allow respecting the dose limits established by the various space agencies, the absorbed dose in the considered organ/tissue must be multiplied by the corresponding Relative Biological Effectiveness (RBE), which is a complex quantity depending on several factors including particle type and energy, considered biological effect, level of effect (and thus absorbed dose), etc. While in several studies only the particle-type dependence of RBE is taken into account, in this work we developed and applied a new approach where, thanks to an interface between the FLUKA Monte Carlo transport code and the BIANCA biophysical model, the RBE dependence on particle energy and absorbed dose was also considered. Furthermore, we included in the considered SPE spectra primary particles heavier than protons, which in many studies are neglected. This approach was then applied to the October 2003 SPE (the most intense SPE of solar cycle 23, also known as "Halloween event") and the January 2005 event, which was characterized by a lower fluence but a harder spectrum, i.e., with higher-energy particles. The calculation outcomes were then discussed and compared with the current dose limits established for skin and blood forming organs in case of 30-days missions. This work showed that the BIANCA model, if interfaced to a radiation transport code, can be used to calculate the RBE values associated to Solar Particle Events. More generally, this work emphasizes the importance of taking into account the RBE dependence on particle energy and dose when calculating equivalent doses.


Assuntos
Radiação Cósmica , Eficiência Biológica Relativa , Atividade Solar , Radiação Cósmica/efeitos adversos , Humanos , Voo Espacial , Método de Monte Carlo , Astronautas , Doses de Radiação
2.
Phys Rev Lett ; 130(6): 061002, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36827578

RESUMO

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28} cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25} cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

3.
Acta Otorhinolaryngol Ital ; 32(3): 189-91, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22767985

RESUMO

The surgical treatment of sinonasal malignancies is in continuous evolution. In selected patients, endoscopic resection has become a sound alternative to traditional external approaches. Further improvements are necessary to enhance the possibilities of endoscopic transnasal resection of sinonasal malignancies. We present a case of intestinal-type adenocarcinoma of the left nasal fossa eroding the skull base that affected a 56-year-old male. The patient was surgically-treated by means of a four-hand binarial endoscopic transnasal resection using a 3D endoscopic system and neuronavigation. Surgery was completed in 5 hours without significant complications. Surgeons were able to recognize and manage anatomical structures, and to control bleeding easily thanks to the bimanual technique and 3D visualization. The new 3D scopes and the bimanual technique under the guidance of a navigation system represent an interesting solution that can overcome the traditional limits of the traditional set up currently used.


Assuntos
Endoscópios , Endoscopia/métodos , Neuronavegação/métodos , Neoplasias da Base do Crânio/cirurgia , Desenho de Equipamento , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Nariz
4.
Ann Ital Chir ; 68(1): 89-93; discussion 93-4, 1997.
Artigo em Italiano | MEDLINE | ID: mdl-9235870

RESUMO

The authors present the case of a primitive small cell esophageal carcinoma. It is a rare and biologically aggressive neoplasm which occurs mainly in the elder male. The case observed concerns a 69 year old female treated with surgical therapy consisting in esophagectomy and intrathoracic esophagealgastrictype plasty. Diagnostic problems either histological or immunohistochemical and the choice of the following treatment are discussed. The cases of patients treated in other Surgical or Oncological centers are reported. Therapeutic orientation adopted by our group is stressed. In this case we have chosen surgical therapy because a sure diagnosis come be given only on the base of the attent histological examination of the entire specimen (endoscopic biopsies are not sufficient); survival data reported are in favour of surgical treatment where secondary metastases are not evident in the respect of antiblastic therapy and/or radiotherapy. Neoplastic recurrence occurred ten months after and a metallic endoscopic esophageal prothesis was positioned. The patient died 1 year after surgery by mediastinal syndrome.


Assuntos
Carcinoma de Células Pequenas/cirurgia , Neoplasias Esofágicas/cirurgia , Idoso , Carcinoma de Células Pequenas/diagnóstico , Carcinoma de Células Pequenas/diagnóstico por imagem , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/diagnóstico por imagem , Esofagectomia , Feminino , Humanos , Tomografia Computadorizada por Raios X
5.
Ann Ital Chir ; 64(5): 481-8, 1993.
Artigo em Italiano | MEDLINE | ID: mdl-8010575

RESUMO

The authors report their experience about cervical metastasis of unknown primitive neoplasms. Epidemiology, histological type and topography are exposed. Primaries which are responsible, in a high incidence, of the preceding cervical localizations are described. Diagnostic iter, non-invasive/low-price clinical and instrumental procedures, advanced endoscopic and radiologic procedures are discussed. 64 patients were treated. Only in one case we could diagnose the primitive site of the neoplasm with non-invasive procedures. The other cases (63 patients) underwent the excision-biopsy of the cervical nodes. In 52 cases we have been able to define the primitive site of the neoplasm. 11 patients, in which the primary was unknown, underwent the radiotherapy of the cervical nodes and the eventual primitive "foci"; we had no survival, on the average, after six months for the diffuse dissemination of the neoplastic disease.


Assuntos
Neoplasias de Cabeça e Pescoço/secundário , Neoplasias Primárias Desconhecidas , Idoso , Feminino , Seguimentos , Neoplasias de Cabeça e Pescoço/radioterapia , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade
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