1,721,065 research outputs found
PCR amplification of GC-rich templates containing palindromic sequences using initial alkali denaturation
No full textRadiation dose in nuclear medicine: the hybrid imaging
Full text linkHybrid imaging procedures such as single-photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography/computed tomography (PET/CT) showed a rapid diffusion in recent years because of their high sensitivity, specificity, and accuracy, due to a more accurate localization and definition of scintigraphic findings. However, hybrid systems inevitably lead to an increase in patient radiation exposure because of the added CT component. Effective doses due to the radiopharmaceuticals can be estimated by multiplying the administered activities by the effective dose coefficients, while for the CT component the dose-length product can be multiplied by a conversion coefficient k. However, the effective dose value is subject to a high degree of uncertainty and must be interpreted as a broad, generic estimate of biologic risk. Although the effective dose can be used to estimate and compare the risk of radiation exposure across multiple imaging techniques, clinicians should be aware that it represents a generic evaluation of the risk derived from a given procedure to a generic model of the human body. It cannot be applied to a single individual and should not be used for epidemiologic studies or the estimation of population risks due to the inherent uncertainties and oversimplifications involved. Practical ways to reduce radiation dose to patients eligible for hybrid imaging involve adjustments to both the planning phase and throughout the execution of the study. These methods include individual justification of radiation exposure, radiopharmaceutical choice, adherence to diagnostic reference levels (DLR), patient hydration and bladder voiding, adoption of new technical devices (sensitive detectors or collimators) with new reconstruction algorithms, and implementation of appropriate CT protocols and exposure parameters
A simple analysis of the Dick effect in terms of Phase Noise spectral density,
No full textIEEE TRANS. UFF
Effect of Abelson murine leukemia virus on granulocytic differentiation and interleukin-3 dependence of a murine progenitor cell line
No full textThe murine diploid hematopoietic cell line 32D C13 strictly requires interleukin-3 (IL-3) for proliferation. When 32D C13 cells are transferred to IL-3-free medium which contains recombinant human granulocyte colony stimulating factor (rhG-CSF), the cell number increases four- to five-fold, and after 14 days the whole cell population is differentiated into morphologically normal and myeloperoxidase- and lactoferrin-positive metamyelocytes and granulocytes. Infection with Abelson murine leukemia virus (A-MuLV) of 32D C13 cells growing in the presence of IL-3 induces, within 2 weeks, the appearance of cells that are IL-3-independent for growth. The latter cells lack myeloid, T and B cell markers, and are unable to differentiate, even in the presence of very high doses of rhG-CSF. However, once the 32D C13 cells have been exposed to G-CSF, they become resistant to the transforming effects of A-MuLV as judged by the appearance of the IL-3-independent clones. These findings suggest that the ability of Abelson virus to transform immature progenitor cells is due to interference of the v-abl gene product with the mechanism that control the commitment of the cells to differentiate
20 anni al fronte: indagini archeologiche della e attraverso la Grande Guerra sugli Altopiani Veneto-Trentini
No full textNegli ultimi decenni, si è assistito a uno sviluppo nel modo di percepire e studiare gli eventi correlati alla Prima Guerra Mondiale, e nuovi slanci e prospettive sono stati forniti anche dall’archeologia. Il filone di ricerche dell’archeologia della Grande Guerra mira infatti ad analizzare le dinamiche di formazione del warscape (cioè il paesaggio di guerra) e il suo impatto sul territorio attraverso metodologie proprie della ricerca archeologica. L’attività di ricerca svolta in questo ambito dall’Università degli Studi di Padova negli ultimi vent’anni ha interessato il fronte prealpino italiano.
Nello specifico, questo contributo presenta i risultati ottenuti nell’indagine multidisciplinare della linea difensiva austro-ungarica Winterstellung sull’Altopiano dei Sette Comuni (VI). Il passaggio di questa linea trincerata impattò significativamente sulle preesistenze archeologiche, sconvolgendone i depositi. Verranno qui presentanti i dati dello scavo stratigrafico di un tratto di linea trincerata e dell’emiscavo di due buche di bomba che hanno permesso di mettere in luce le dinamiche post-deposizionali obliterative naturali e le bonifiche antropiche che hanno interessato le evidenze belliche a partire dalla fine del conflitto
Retroviral vector-mediated transfer of the tumor necrosis factor a gene into human cancer cells restores an apoptotic cell death program and induces a bystander-killing effect.
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