732 research outputs found
S-35 Beta Irradiation of a Tin Strip in a State of Superconducting Geometrical Metastability
We report the first energy loss spectrum obtained with a geometrically
metastable type I superconducting tin strip irradiated by the beta-emission of
S-35. (Nucl. Instr. Meth. A, in press)Comment: Compressed PostScript (filename.ps.Z), 9 pages, 2 figure
Nuclear recoil measurements in Superheated Superconducting Granule detectors
The response of Superheated Superconducting Granule (SSG) devices to nuclear
recoils has been explored by irradiating SSG detectors with a 70MeV neutron
beam. In the past we have tested Al SSG and more recently, measurements have
been performed with Sn and Zn detectors. The aim of the experiments was to test
the sensitivity of SSG detectors to recoil energies down to a few keV. In
this paper, the preliminary results of the neutron irradiation of a SSG
detector made of Sn granules 15-20m in diameter will be discussed. For the
first time, recoil energy thresholds of 1keV have been measured.Comment: 7pages in Latex format, Preprint Bu-He 93/6 (University of Berne,
Switzerland), four figures available upon request via
[email protected] or [email protected]
Haemodynamic consequences of changing bicarbonate and calcium concentrations in haemodialysis fluids
Background. In a previous study we demonstrated that mild metabolic alkalosis resulting from standard bicarbonate haemodialysis induces hypotension. In this study, we have further investigated the changes in systemic haemodynamics induced by bicarbonate and calcium, using non-invasive procedures
Coverage, efficacy or dosing interval: which factor predominantly influences the impact of routine childhood vaccination for the prevention of varicella? A model-based study for Italy
Background: Varicella is a highly infectious disease with a significant public health and economic burden, which can be prevented with childhood routine varicella vaccination. Vaccination strategies differ by country. Some factors are known to play an important role (number of doses, coverage, dosing interval, efficacy and catch-up programmes), however, their relative impact on the reduction of varicella in the population remains unclear. This paper aims to help policy makers prioritise the critical factors to achieve the most successful vaccination programme with the available budget. Methods: Scenarios assessed the impact of different vaccination strategies on reduction of varicella disease in the population. A dynamic transmission model was used and adapted to fit Italian demographics and population mixing patterns. Inputs included coverage, number of doses, dosing intervals, first-dose efficacy and availability of catch-up programmes, based on strategies currently used or likely to be used in different countries. The time horizon was 30 years. Results: Both one- and two-dose routine varicella vaccination strategies prevented a comparable number of varicella cases with complications, but two-doses provided broader protection due to prevention of a higher number of milder varicella cases. A catch-up programme in susceptible adolescents aged 10-14 years old reduced varicella cases by 27-43 % in older children, which are often more severe than in younger children. Coverage, for all strategies, sustained at high levels achieved the largest reduction in varicella. In general, a 20 % increase in coverage resulted in a further 27-31 % reduction in varicella cases. When high coverage is reached, the impact of dosing interval and first-dose vaccine efficacy had a relatively lower impact on disease prevention in the population. Compared to the long (11 years) dosing interval, the short (5 months) and medium (5 years) interval schedules reduced varicella cases by a further 5-13 % and 2-5 %, respectively. Similarly, a 10 % increase in first-dose efficacy (from 65 to 75 % efficacy) prevented 2-5 % more varicella cases, suggesting it is the least influential factor when considering routine varicella vaccination. Conclusions: Vaccination strategies can be implemented differently in each country depending on their needs, infrastructure and healthcare budget. However, ensuring high coverage remains the critical success factor for significant prevention of varicella when introducing varicella vaccination in the national immunisation programme
G-genotyping of rotaviruses in stool samples in Salento, Italy
Rotaviruses are the most common agents of diarrhoeal illnessin infants and young children. Gastroenteritis caused byrotaviruses is also more likely to be associated with severe dehydration compared to other viral gastroenteritis.We determined the G-genotype of rotaviruses circulating in theSalento. During 2004, 144 stool samples were collected fromsubjects with a positive screening test and stored at -20 °C untilconfirmation could take place using molecular biology techniques. A reverse transcription-polymerase chain reaction (RTPCR) assay for the amplification of gene VP7 of rotavirus wasdeveloped and used; G-genotype was determined by sequencing and phylogenetic analysis. A total of 101 stool samples were detected positive by RT-PCRand 35 were sequence analyzed and classified into G1, G2, G4,G9 and G12 type. The overall relative incidence of G-types inSalento is different to that of other developed countries. Themost prevalent genotype was G2 while genotype G1 was present at low levels. It is also interesting to note the presence ofG9 rotavirus, which is now recognized as the fifth globallyimportant rotavirus genotype.In this study, therefore, we demonstrate the usefulness of a simple method for correctly determining the G genotypes circulating in a geographic region
Beta Irradiation of a Geometrically Metastable Superconducting Strip Detector with a Magnetic Flux Penetration Read-Out
Geometrical metastability, observed in superconducting type I tin flat
strips, has been previously proposed as a principle for particle detection. The
energy deposition of an incoming beta-particle induces the rupture of the
metastability and consequently the penetration of multiquantum flux tubes into
a superconducting tin strip. We present here the first absorption spectra from
two beta sources, which demonstrate the linearity and energy-resolution of
these detectors (presented at the 6th International Workshop on Low Temperature
Detectors for Dark Matter and Neutrinos (LTD-6), Interlaken, Switzerland, Sept.
1995)Comment: Compressed PostScript (filename.ps.Z), 8 pages, 2 figure
Phase Transition Study of Superconducting Microstructures
The presented results are part of a feasibility study of superheated
superconducting microstructure detectors. The microstructures (dots) were
fabricated using thin film patterning techniques with diameters ranging from
m up to m and thickness of m. We used arrays and single
dots to study the dynamics of the superheating and supercooling phase
transitions in a magnetic field parallel to the dot surface. The phase transi-
tions were produced by either varying the applied magnetic field strength at a
constant temperature or changing the bath temperature at a constant field.
Preliminary results on the dynamics of the phase transitions of arrays and
single indium dots will be reported.Comment: 7pages in LaTex format, five figures available upon request by
[email protected], preprint Bu-He 93/
The unmet need for pertussis prevention in patients with chronic obstructive pulmonary disease in the Italian context
Despite high rates of vaccination, pertussis resurgence has been reported worldwide in recent years, including in Italy, especially in older adults. Chronic obstructive pulmonary disease (COPD) is a respiratory disease associated with progressive inflammation of the respiratory tract. Regional population studies have shown the prevalence of COPD in Italy to be approximately 15% with an age-dependent increase in proportion of COPD cases. Emerging data shows that individuals with COPD are at high risk of contracting pertussis. Furthermore, those who develop pertussis could experience exacerbation of their pre-existent COPD and further susceptibility to other infections. Immunization programs in Italy currently recommend a decennial reduced-antigen-content diphtheria-tetanus-acellular pertussis booster vaccine dose for adults. Active measures to encourage booster vaccination, especially for high-risk adults such as those with COPD, could positively impact pertussis morbidity and the associated healthcare burden
Herpes zoster vaccination in the elderly subjects: improving awareness and uptake
Armando Stefanati, Nicoletta Valente, Silvia Lupi, Sara Previato, Matilde Giordani, Giovanni Gabutti Department of Medical Sciences, University of Ferrara, Ferrara, Italy Abstract: Herpes zoster (HZ) is a common disease in adults and older subjects solely related to the reactivation of latent varicella zoster virus in ganglia. The incidence of the disease increases with aging and the decline of varicella zoster virus-specific cell-mediated immunity. HZ has a significant impact on the quality of life of subjects during the acute phase. Besides, pain can persist even for a long time becoming chronic. The chronic pain following HZ is called postherpetic neuralgia, and it is a debilitating long-lasting condition, characterized by metameric pain, allodynia, and hyperalgesia. Therapeutic options against HZ and postherpetic neuralgia are often suboptimal and the impact of the disease and its complications on daily living activities is significant, especially in older subjects. Nowadays, a preventive approach to the disease is possible; as a matter of fact, a high-antigen content live vaccine is available. This vaccine has a good profile in terms of immunogenicity, efficacy, effectiveness, and safety and its use may prevent both HZ and postherpetic neuralgia. Nevertheless, the evaluation of the issues raised in countries that introduced this immunization show that both provider and patient barriers could have prevented a more robust uptake of HZ vaccination. In the USA, HZ immunization storage was expensive, reimbursement was cumbersome, and supply shortages may have limited promotion by the interests of the manufacturer and provider. The doctors did not actively recommend HZ vaccination; on the other hand, subjects were mostly unaware of the HZ vaccine. Several demographic factors, including sex and educational level, could have negatively affected the coverage rates; besides, the clinicians who treat adults focus less on vaccination than those taking care of children. On the other hand, when health care professionals undertook every effort to maximize the uptake of the shingles vaccine (eg, in the UK), the vaccine coverage rate increased very quickly. Keywords: herpes zoster, postherpetic neuralgia, vaccin
Effect of stripe clearing on 4 grasses species and 2 broadleaves of caldenal
En la Región del Espinal, Distrito del Caldén, en la provincia de San Luis existe un fuerte proceso de agriculturización con la consecuente pérdida de remanentes de bosque nativo, peligro de conservación de especies nativas e invasión de especies exóticas. El objetivo del presente trabajo fue evaluar el efecto del desmonte en franjas sobre 6 especies del caldenal (4 gramíneas y 2 latifoliadas). El estudio se realizó en un campo a 15 km. al norte de la ciudad de Villa Mercedes (San Luis), sometido a un desmonte en franjas para uso agrícola en el año 2003. En 5 sitios ubicados en franjas remanentes de bosque nativo y 5 en bosque nativo sin desmonte, se trazaron transectas de 39 m de longitud, dirección NS y a lo largo de la misma se registraron las especies presentes en 14 unidades de muestreo de 1 m2. Los datos se analizaron utilizando IBM SPSS Statistics 19, mediante Métodos No Paramétricos, U de Mann-Whitney. El análisis estadístico mostró diferencias significativas (p<0.05) en Digitaria californica, Pappophorum pappiferum, Salsola kali y Cestrum parqui. El estudio demostró que el cultivo entre franjas de bosque nativo produjo un cambio en la frecuencia de poáceas nativas y de latifoliadas.In the region of “Espinal”, Calden Distrct in the province of San Luis there is a strong agriculturization process with the consequent loss of native forest remnants, conserving endangered native species and invasion of exotic species. The aim of this study was to evaluate the effect of the stripe clearing on 6 species of caldenal (4 grasses and 2 broa- dleaves). The study was conducted in a field 15 km to the north of the city of Villa Mercedes (San Luis), subjected to a strip-clearing for agricultural use, in the year 2003. On 5 sites into native forest remnants stripes and 5 into without clearing native forest, 39 m long tran- sects were laid, N-S direction, and along the same were recorded the presente species in 14 sampling units of 1 m2. Data were analyzed by IBM SPSS Statistics 19, through non- parametric methods, Mann-Whitney U. Statistical analysis showed significant differences (p <0.05) in Digitaria californica, Pappophorum pappiferum, Salsola kali and Cestrum par- qui. The study showed that the cultivation of native forest between stripes was a change in the frequency of native grasses and broadleaves.Fil: Ruiz, O. M.. Universidad Nacional de San Luis; Argentina;Fil: Luna, H. R.. Universidad Nacional de San Luis; Argentina;Fil: Bacha, Emmanuel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - San Luis; Argentina; Universidad Nacional de San Luis; Argentina;Fil: Pedranzani, H.. Universidad Nacional de San Luis; Argentina;Fil: Gabutti, E.G.. Universidad Nacional de San Luis; Argentina
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