RESUMO
The requirements of ITER neutral beam injectors (1 MeV, 40 A negative deuterium ion current for 1 h) have never been simultaneously attained; therefore, a dedicated Neutral Beam Test Facility (NBTF) was set up at Consorzio RFX (Padova, Italy). The NBTF includes two experiments: SPIDER (Source for the Production of Ions of Deuterium Extracted from Rf plasma), the full-scale prototype of the source of ITER injectors, with a 100 keV accelerator, to investigate and optimize the properties of the ion source; and MITICA, the full-scale prototype of the entire injector, devoted to the issues related to the accelerator, including voltage holding at low gas pressure. The present paper gives an account of the status of the procurements, of the timeline, and of the voltage holding tests and experiments for MITICA. As for SPIDER, the first year of operation is described, regarding the solution of some issues connected with the radiofrequency power, the source operation, and the characterization of the first negative ion beam.
RESUMO
This Letter reports on an optical pumping scheme, termed resonant pumping, for an erbium-doped distributed feedback (DFB) waveguide laser. The scheme uses two mirrors on either side of the DFB laser, forming a pump cavity that recirculates the unabsorbed pump light. Symmetric distributed Bragg reflectors are used as the mirrors and are designed by matching the external and internal quality factors of the cavity. Experimental demonstration shows lasing at an optical communication wavelength of around 1560 nm and an improvement of 1.8 times in the lasing efficiency, when the DFB laser is pumped on-resonance.
RESUMO
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Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Trombose Venosa/induzido quimicamente , Trombose Venosa/complicações , Trombose Venosa/diagnóstico , Artrite Infecciosa/induzido quimicamente , Artrite Infecciosa/classificação , Avaliação de Sintomas/classificação , Avaliação de Sintomas , Trombose Venosa/sangue , Trombose Venosa/enfermagem , Trombose Venosa/prevenção & controle , Artrite Infecciosa/complicações , Artrite Infecciosa/metabolismo , Artrite Infecciosa/patologia , Avaliação de Sintomas/enfermagem , Avaliação de Sintomas/normas , Costa Rica/etnologiaAssuntos
Artrite Infecciosa/complicações , Artrite Infecciosa/microbiologia , Miosite/complicações , Miosite/microbiologia , Osteomielite/complicações , Osteomielite/microbiologia , Infecções Estafilocócicas/complicações , Trombose Venosa/microbiologia , Doença Aguda , Criança , Costa Rica , Humanos , Lactente , MasculinoRESUMO
BACKGROUND: Brazil requires the performance of both a test for hepatitis B surface antigen (HBsAg) and a test for antibodies to the core of hepatitis B for blood donor screening. Blood centres in regions of high HBV endemicity struggle to maintain adequate stocks in face of the high discard rates due to anti-HBc reactivity. We evaluated the potential infectivity of donations positive for anti-HBc in search of a rational approach for the handling of these collections. STUDY DESIGN AND METHODS: We tested anti-HBc reactive blood donations from the state of Amazonas for the presence of HBV DNA and for titres of anti-HBs. The study population consists of village-based donors from the interior of Amazonas state. RESULTS: Among 3600 donations, 799 were anti-HBc reactive (22·2%). We were able to perform real-time PCR for the HBV S gene on specimens from 291 of these donors. Eight of these samples were negative for HBsAg and positive for HBV DNA and were defined as occult B virus infections (2·7%). Six of those eight specimens had anti-HBs titres above 100 mIU/ml, indicating the concomitant presence of the virus with high antibody titres. CONCLUSION: A small proportion of anti-HBc reactive donors carry HBV DNA and anti-HBs testing is not useful for predicting viremia on them. This finding indicates the possibility of HBV transmission from asymptomatic donors, especially in areas of high HBV prevalence. Sensitive HBV DNA nucleic acid testing may provide another level of safety, allowing eventual use of anti-HBc reactive units in critical situations.
Assuntos
Doadores de Sangue , Transfusão de Sangue/métodos , Controle de Doenças Transmissíveis/métodos , Hepatite B/sangue , Hepatite B/epidemiologia , Adulto , Transfusão de Sangue/normas , Brasil/epidemiologia , DNA Viral/sangue , DNA Viral/isolamento & purificação , Anticorpos Anti-Hepatite B/sangue , Antígenos do Núcleo do Vírus da Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/sangue , Vírus da Hepatite B/genética , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Viremia/sangueRESUMO
The incidence rate of primary intracranial tumors in the Province of Trento from 1977 to 1981 was 7.4 per 100,000 inhabitants per year. The age curve is as reported by other authors, with two peaks, one early and the other, much higher, at 50-59 years. This curve reflects that of malignant tumors in males. The age-adjusted crude rate in males proved to be 7.4 (4.9 for malignant and 2.5 for benign tumors). The corresponding value in females was 7.4 (3.5 and 4.0). The most frequent tumors in males were astrocytomas, grades III and IV (M/F ratio = 1.6), and in females meningiomas (M/F ratio = 0.6). Hypophyseal adenomas, which accounted for 15.4% of all tumors, had an M/F ratio of 0.4. The factors likely to be responsible for the differences in incidence rates reported in the various surveys are discussed.
