1,721,184 research outputs found
Valori di riferimento per gli esami di funzionalità respiratoria
No full textThe spirometric reference values used in Occupational
Medicine are generally derived from the tables ECSC 71 or from the
“summary equations” ECSC/ERS 83-93. To identify the most
appropriate ones for the laboratory of Cagliari we have calculated the
sum of the residuals (_R) between the individual observed and predicted
value relatively to the Vital Capacity (VC), the FEV1 and the Residual
Volume (RV) on a sample of 163 healthy males. While the ΣR for the VC
is very near to the zero (-0.022 litres) using the ECSC 71 reference
values, the observed values are in average 323 ml higher than the
CECA/ERS 83-93 predictions. Similar results are observed for the FEV1
(ΣR +0.041 using the CECA71 values and +0.187 using the CECA/ERS
83-93 equations). Also as it regards the RV the CECA71 reference values
are more appropriate for our normal subjects (ΣR +0.038 litres) in
comparison to those derived from the CECA/ERS 83-93 equations
resulting too elevated (ΣR –0.445 litres). In conclusion, the reference
values drawn from the ECSC 71 tables result more appropriate for our
laboratory both for the dynamic and static volumes, being the
CECA/ERS 83-93 reference values too low for the dynamic volumes and
too high for the static volumesThe spirometric reference values used in Occupational
Medicine are generally derived from the tables ECSC 71 or from the
“summary equations” ECSC/ERS 83-93. To identify the most
appropriate ones for the laboratory of Cagliari we have calculated the
sum of the residuals (_R) between the individual observed and predicted
value relatively to the Vital Capacity (VC), the FEV1 and the Residual
Volume (RV) on a sample of 163 healthy males. While the ΣR for the VC
is very near to the zero (-0.022 litres) using the ECSC 71 reference
values, the observed values are in average 323 ml higher than the
CECA/ERS 83-93 predictions. Similar results are observed for the FEV1
(ΣR +0.041 using the CECA71 values and +0.187 using the CECA/ERS
83-93 equations). Also as it regards the RV the CECA71 reference values
are more appropriate for our normal subjects (ΣR +0.038 litres) in
comparison to those derived from the CECA/ERS 83-93 equations
resulting too elevated (ΣR –0.445 litres). In conclusion, the reference
values drawn from the ECSC 71 tables result more appropriate for our
laboratory both for the dynamic and static volumes, being the
CECA/ERS 83-93 reference values too low for the dynamic volumes and
too high for the static volumes
Surface Heterogeneity Affects Adsorption Selectivity for CO2 Over CH4 in Bare Mesostructured Silica with 2D Hexagonal Symmetry and Different Pore Size
Full text linkMesoporous silica-based materials are used as sorbents and supports in many fields. The ordered pore architecture of MCM-41, and the absence of interconnections, make it suitable as a model system. The surface is natively functionalized by many silanol groups, endowing the material with a polar surface to directly interact with the target species or to mount additional functional groups. Either bare or functionalized, surface silanol arrangement is crucial to material performance. In the case of CO2 capture with amine-functionalized silica, silanol groups are responsible for fundamental H-bonds during chemisorption, but they also modulate the effect and weight of humidity on the material performance. In addition, the silanol groups can also tune the weight of physisorption over chemisorption. The relationship between these aspects and the textural features of mesostructured silica has not been addressed in detail. In this study, computer models are employed to investigate the adsorption capacity and selectivity of bare mesostructured silica with three different pore sizes. Results are rationalized in terms of silanol surface density and pore curvature. The importance of the energetic inequivalence between Q3 and Q2 sites on the silica surface is emphasized, as this causes adsorption behavior to deviate from ideality
Monitoring CP usage in dairy cattle rations by using milk urea as indicator in a nitrate vulnerable area
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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