2,016 research outputs found
Value of Information: A Tool to Improve Research Prioritization and Reduce Waste
In a Guest Editorial, Cosetta Minelli and Gianluca Baio explain how VOI analysis can prioritize research projects by identifying uncertainty in existing knowledge and then estimating expected benefits from reducing that uncertainty
Value of Information: A Tool to Improve Research Prioritization and Reduce Waste.
In a Guest Editorial, Cosetta Minelli and Gianluca Baio explain how VOI analysis can prioritize research projects by identifying uncertainty in existing knowledge and then estimating expected benefits from reducing that uncertainty
Modeling mass transport in dense polymer membranes: cooperative synergy among multiple scale approaches
The modeling description of basic transport phenomena of either liquid, gas or vapor molecules in dense polymeric membranes is of tremendous impact for the separation industry, which relies on solid models for the design of optimal process conditions, for the selection of the most suitable membrane materials as well as for the development of novel ones. Such models need to deal with several physical aspects and phenomena, spanning over broad time and length scales, thus requiring multiple approaches. The solid frameworks now available mainly rely on the solution–diffusion theory, in which equation of state models and free volume theories are applied for the description of thermodynamic and kinetic properties, to be coupled in appropriate transport schemes
Systematic review of statistical approaches to quantify, or correct for, measurement error in a continuous exposure in nutritional epidemiology.
BACKGROUND: Several statistical approaches have been proposed to assess and correct for exposure measurement error. We aimed to provide a critical overview of the most common approaches used in nutritional epidemiology. METHODS: MEDLINE, EMBASE, BIOSIS and CINAHL were searched for reports published in English up to May 2016 in order to ascertain studies that described methods aimed to quantify and/or correct for measurement error for a continuous exposure in nutritional epidemiology using a calibration study. RESULTS: We identified 126 studies, 43 of which described statistical methods and 83 that applied any of these methods to a real dataset. The statistical approaches in the eligible studies were grouped into: a) approaches to quantify the relationship between different dietary assessment instruments and "true intake", which were mostly based on correlation analysis and the method of triads; b) approaches to adjust point and interval estimates of diet-disease associations for measurement error, mostly based on regression calibration analysis and its extensions. Two approaches (multiple imputation and moment reconstruction) were identified that can deal with differential measurement error. CONCLUSIONS: For regression calibration, the most common approach to correct for measurement error used in nutritional epidemiology, it is crucial to ensure that its assumptions and requirements are fully met. Analyses that investigate the impact of departures from the classical measurement error model on regression calibration estimates can be helpful to researchers in interpreting their findings. With regard to the possible use of alternative methods when regression calibration is not appropriate, the choice of method should depend on the measurement error model assumed, the availability of suitable calibration study data and the potential for bias due to violation of the classical measurement error model assumptions. On the basis of this review, we provide some practical advice for the use of methods to assess and adjust for measurement error in nutritional epidemiology
Robotic versus laparoscopic approach in colonic resections for cancer and Benign diseases. Systematic review and meta-analysis
Objectives The aim of this systematic review and meta-Analysis is to compare robotic colectomy (RC) with laparoscopic colectomy (LC) in terms of intraoperative and postoperative outcomes. Materials and Methods A systematic literature search was performed to retrieve comparative studies of robotic and laparoscopic colectomy. The databases searched were PubMed, Embase and the Cochrane Central Register of Controlled Trials from January 2000 to October 2014. The Odds ratio, Risk difference and Mean difference were used as the summary statistics. Results A total of 12 studies, which included a total of 4,148 patients who had undergone robotic or laparoscopic colectomy, were included and analyzed. RC demonstrated a longer operative time (MD 41.52, P<0.00001) and higher cost (MD 2.42, P<0.00001) than did LC. The time to first flatus passage (MD-0.51, P = 0.003) and the length of hospital stay (MD-0.68, P = 0.01) were significantly shorter after RC. Additionally, the intraoperative blood loss (MD-16.82, P<0.00001) was significantly less in RC. There was also a significantly lower incidence of overall postoperative complications (OR 0.74, P = 0.02) and wound infections (RD-0.02, P = 0.03) after RC. No differences in the postoperative ileus, in the anastomotic leak, or in the conversion to open surgery rate and in the number of harvested lymph nodes outcomes were found between the approaches. Conclusions The present meta-Analysis, mainly based on observational studies, suggests that RC is more time-consuming and expensive than laparoscopy but that it results in faster recovery of bowel function, a shorter hospital stay, less blood loss and lower rates of both overall postoperative complications and wound infections. Copyright: © 2015 Trastulli et al.OBJECTIVES:
The aim of this systematic review and meta-analysis is to compare robotic colectomy (RC) with laparoscopic colectomy (LC) in terms of intraoperative and postoperative outcomes.
MATERIALS AND METHODS:
A systematic literature search was performed to retrieve comparative studies of robotic and laparoscopic colectomy. The databases searched were PubMed, Embase and the Cochrane Central Register of Controlled Trials from January 2000 to October 2014. The Odds ratio, Risk difference and Mean difference were used as the summary statistics.
RESULTS:
A total of 12 studies, which included a total of 4,148 patients who had undergone robotic or laparoscopic colectomy, were included and analyzed. RC demonstrated a longer operative time (MD 41.52, P<0.00001) and higher cost (MD 2.42, P<0.00001) than did LC. The time to first flatus passage (MD -0.51, P = 0.003) and the length of hospital stay (MD -0.68, P = 0.01) were significantly shorter after RC. Additionally, the intraoperative blood loss (MD -16.82, P<0.00001) was significantly less in RC. There was also a significantly lower incidence of overall postoperative complications (OR 0.74, P = 0.02) and wound infections (RD -0.02, P = 0.03) after RC. No differences in the postoperative ileus, in the anastomotic leak, or in the conversion to open surgery rate and in the number of harvested lymph nodes outcomes were found between the approaches.
CONCLUSIONS:
The present meta-analysis, mainly based on observational studies, suggests that RC is more time-consuming and expensive than laparoscopy but that it results in faster recovery of bowel function, a shorter hospital stay, less blood loss and lower rates of both overall postoperative complications and wound infections
Neogene to Quaternary evolution of the Calabrian Subduction System, (Central Mediterranean)
We construct an ESE striking to WNW geological cross-section across the Calabrian Subduction System (Central
Mediterranean) using seismic near vertical profiles and field data. The interpreted profiles were time-to-depth
converted, merged and translated in a geological section stretching from the Marsili Oceanic Basin (Southern
Tyrrhenian Sea) to the Ionian accretionary complex . Moving toward the east, the resulting section through the
Paola, Amantea, and Crati basins, the Coastal Chain and Sila Massif and Crotone basin. The maximum elongation
of these basins change progressively moving toward the east: from NNW in the Paola to NS in the Crati to the NNE
in the Crotone basins. Data we present suggest that: Across the Calabria Tyrrhenian Continental Margin (CTCM),
top of Kabilian-Calabrian Unit (KCU) is laterally variable in depth forming basins, which are separated by major
structures with contractional or transcurrent kinematics, filled by Oligo-Miocene clastic to evaporitic deposits up to
1500m thick. Plio-Quaternary deposits display a remarkable variation in thickness from 4.5 km in the Paola Basin
to less than 400m in the central sector of the margin. Plio-Quaternary sediments are internally sub-divisible into
four sub-units (namely D1-D4) separated by tectonics enhanced angular unconformities. W-ward vergent reverse
faults with limited vertical displacement offset the top of KCU as well as the Oligo-Miocene sedimentary and evaporitic
units in the eastern side of the Paola basin. On land (Amantea \u2013 Crati) and farther to the east (Crotone basin)
below a Messinian-Pleistocene deposits the top of KCU is variable structured and covered by a Oligo-Miocene
clastic deposits with different thickness. The Plio-Quaternary deposits, unconformably overlay the Messinian and
older deposits, show the maximum thickness in the Crotone basin. Two main tectonic unconformities within the
Plio-Quaternary deposits have been recognised allowing the separation of this unit into three sub-units. In the
offshore portion of the Crotone basin, SE-ward reverse faults dissect the KCU and the Oligo-Miocene up to the
Messinian deposits. While the pre-Messinian tectonic history across the Calabrian Subduction System seems to
be quite similar, a main reorganization of the system occurring during the (?) early and (?) middle-Pliocene. Geometrical
and stratigraphic relationship show that several W-ward and E-ward vergent reverse faults in the Paola
and Crotone basins, respectively, cut and offset Messinian evaporites and older sedimentary units, controlling the
geometry of the basins. In the Paola Basin the amount of subsidence gradually increase during deposition of subunits
D2 and D3, which are probably Pliocene in age. On land, the evidence of the unconformities in the Crotone
basin indicate that Pliocene deposition occurring during the uplift of the Sila Massif. Therefore uplift of the Sila
range occurred during the strong subsidence of the Paola and Crotone basins.
The evolution of the overall structure can be then divided in two different steps: 1)the onset of subsidence started
in the Late Miocene and covered a large areas presently occupied by the Paola and Crotone basins. This basin, was
probably already separated into sub-basins but evolved in a slowly subsiding and poorly deformed area located
between the active accretionary prism and the volcanic arc. Therefore in the Middle-Upper Miocene this basin
could be defined as forearc basin. 2)In the Pliocene the structure of this large basin was fragmented due to the uplift
of a central range (Sila Massif) with an overall pop-up like structure. 3)Uplift of the belt producing subsidence
along the flanks and simultaneously formation of two distinct basins: the Paola and Crotone basins. This process
probably occurred during episodes of fast roll-back of the subducting slab, as attested by the opening of two ocean
floor basins in the back-arc region
How to describe and predict plasticization in glassy polymeric membranes for gas separations
In glassy polymeric membranes, gas permeability shows different trends as upstream pressure increases, including the monotonous decline, a monotonous increase, as well as an initial decline followed by a subsequent increase after a minimum permeability value is reached. The minimum value, whenever present, occurs at a pressure conventionally indicated as the plasticization pressure. It is currently accepted that permeability behavior can be conveniently well described by a transport model only below plasticization pressure, while above that value the onset of additional phenomena at higher pressures are responsible of the observed increase in permeability and decrease in selectivity. On the other hand, the plasticization phenomenon has not been further inspected thus far, in terms of material property variations.
With the aim to reach to a deeper understanding of the phenomenon, we have experimentally inspected the behavior of Matrimid polyimide membranes, by analyzing both transport and mechanical properties. The permeability behavior and the “plasticization” effects induced by CO2 have been studied by increasing the upstream pressure at different fixed values of downstream pressure. The mechanical properties studied include elastic modulus and viscoelastic response of samples saturated at different CO2 pressures up to and above plasticization pressure. The trends obtained are rather interesting and actually not fully in line with what expected based on the current qualitative interpretation.
We also show that the observed gas permeability behavior can be described by considering only a solution-diffusion model in which the penetrant mobility varies with its concentration in the polymer matrix through an exponential law, with two adjustable parameters only. Diffusivity is thus taken as the product of molecular mobility and a thermodynamic factor, calculated by using the NELF model for thermodynamic properties of the glassy phase. It is observed that by fitting the only two adjustable parameters to the initial branch of the permeability isotherm, the above solubility diffusivity model allows the prediction of the plasticization pressure, at all values of downstream pressures used, without introducing any additional physical phenomenon.
The agreement observed between model calculations and experimental data of CO2 permeability in Matrimid, as well as in various glassy polymers, is very satisfactory. That allows us to offer a deeper insight on the so-called plasticization phenomenon. The analysis of the permeability and the solubility isotherms, and the evaluation of concentration and swelling profiles in the membrane, show that in some cases the plasticization phenomena take place after part of the membrane has turned into rubbery phase. However, in other relevant cases as in Matrimid, the minimum in permeability is observed when the entire membrane is still glassy (and characterized by mechanical behavior comparable to the pure “dry” material), but with a polymer swelling sufficient for a permeability increase.
Finally, it is observed that all parameters used have a defined independent physical meaning, which might lead to the development of general correlations with both polymer and penetrant properties, based on which permeability predictions can be obtained
Mental flexibility in Parkinson's disease with central fatigue: Data from the frontal assessment battery
Background and aims
Central fatigue is defined as a reduced energy level or an
increased perception of effort, often associated to a failure in
initiating and maintaining tasks that require self-motivation. It is
common in Parkinson's disease population and it has been
hypothesized to be related to a dysfunction in the striato-talamo-
prefrontal loop. The aim of the present study was to explore the
association between fatigue and executive functions as index of
integrity of the striato-thalamo-prefrontal loop.
Methods
Twenty-nine non-demented PD patients without fatigue - PDnF,
28 non-demented PD patients with fatigue - PDF and 26 age and sex-
matched controls underwent an evaluation with the Frontal
Assessment Battery (FAB), MMSE, PSQI, BDI, STAI Y1-2, PDQ-39.
Differences between groups in FAB scores (total and subitems) were
analyzed by means of Kruskal-Wallis test. Moreover, a correlation
between fatigue and FAB was also analyzed.
Results
Overall parkinsonian population displayed worse performance
than controls in frontal scores especially inhibitory control (p =
0.008) and sensitivity to interference (p = 0.014). PDF displayed
significantly worse than PDnF in verbal fluency (p = 0.05). Fatigue
severity inversely correlated with executive performance (p b 0.001).
Conclusions
Phonemic fluency tasks are thought to reflect the simultaneous
engagement of several executive functions such as attention,
working memory, retrieval, information processing. The association
of central fatigue with a deficit in mental flexibility, could support
the hypothesis that central fatigue is a reliable index of the
impairment of higher executive functions needed in order to
effectively assess costs and benefits related to adaptive decision-
making behavior
Assessing the Integrated Impact of Sustainable Innovation on Organisational Performance: An Empirical Evidence From Manufacturing Firms
Sustainable Development Goals (SDGs) have gained importance and the world is moving on a sustainability trajectory, which requires organisations to balance financial, environmental, and social dimensions of management. Companies are encouraged to adopt sustainable innovations that include resource efficiency, waste reduction, energy use, responsible behavior etc., to overcome environmental issues and incorporate societal aspects. However, the types of innovations that embrace the so-called triple bottom line philosophy have been tenuously investigated in relation to organisational performance of firms. Through an empirical study, this work investigates the relationship between sustainable innovation in its three dimensions and organisational performance, including stakeholder management, human resource management and process measures, in the context of Italian manufacturing companies. The results show that a greater emphasis on sustainable innovations has a positive impact on the organisational performance and competitive advantage of firms, revealing the key role of human capital and portraying important avenues for future research
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