Induction and measurement of minute flow rates through nanopipes

A simple technique to simultaneously induce fluid flow through an individual nanopipe and measure the flow rate and the pressure difference across the pipe is described. Two liquid drops of different sizes are positioned at the two ends of the nanopipe. Due to the higher capillary pressure of the smaller drop, flow is driven from the smaller drop to the bigger drop. The instantaneous pressures of the two drops are estimated from the drops\u27 shapes and sizes. The flow rate is estimated by monitoring the sizes of the drops as functions of time with a microscope and a video camera. A theory that correlates the drops\u27 sizes and the flow rate is derived. Measurements are carried out with an ionic salt and glycerin to estimate the effective tube radius of the nanopipes with diameters ranging from 200 to 300 nm. The tubes\u27 diameters are independently measured with a scanning electron microscope. The method is also verified by tracking the motion of fluorescent particles through the nanopipe. The paper provides a simple technique for studying extremely low flow rates in nanofluidic systems. When working with low-evaporation fluids such as ionic salts, the measurements can be carried out with an electron microscope

One-to-one relationships between Industry 4.0 technologies and Lean Production techniques: a multiple case study

Production research literature and industry practice have started to pay increasing attention to the Industry 4.0 (I4.0) phenomenon. Scholars and practitioners identified a strong link between this paradigm and the well-known Lean Production (LP) paradigm. Most studies consider LP as a prerequisite of I4.0 and I4.0 as a tool to overcome LP limits and boost its practices. However, so far, these effects have been studied only at a high level, without an in-depth and comprehensive pairwise analysis at a practice-technology level. Moreover, few empirical studies have been carried out on this topic. Our paper attempts to fill these gaps by conducting a multiple case studies research to explain the one-to-one relationships between LP techniques and I4.0 technologies, and vice versa. More specifically, the one-to-one analysis examines the enabling effect of LP on I4.0 and the empowering effect of I4.0 on LP. Based on the empirical analyses, we propose a framework on the relationships between the two paradigms structured into six areas drawn from previous research (i.e., manufacturing equipment and processes, shop-floor management, workforce management, new product development, supplier relationships, customer relationships). Such representation clarifies the interdependence of the two paradigms in the whole supply chain

Digital twin-enabled smart industrial systems: a bibliometric review

The aim of this study is to investigate the body of literature on digital twins, exploring, in particular, their role in enabling smart industrial systems. This review adopts a dynamic and quantitative bibliometric method including works citations, keywords co-occurrence networks and keywords burst detection with the aim of clarifying the main contributions to this research area and highlighting prevalent topics and trends over time. The analysis performed on citations traces the backbone of contributions to the topic, visible within the main path. Keywords co-occurrence networks depict the prevalent issues addressed, tools implemented and application areas. The burst detection completes the analysis identifying the trends and most recent research areas characterizing research on the digital twin topic. Decision-making, process design and life cycle as well as the enabling role in the adoption of the latest industrial paradigms emerge as the prevalent issues addressed by the body of literature on digital twins. In particular, the up-to-date issues of real-time systems and industry 4.0 technologies, closely related to the concept of smart industrial systems, characterize the latest research trajectories identified in the literature on digital twins. In this context, the digital twin can find new opportunities for application in manufacturing, control and services

The Contribution of Case Mix, Skill Mix and Care Processes to the Outcomes of Community Hospitals: A Population-Based Observational Study

Introduction: Community hospitals (CHs) could address the emerging complex care needs of patients. We investigated which characteristics of patients' and CHs affect patient outcomes, in order to identify who could benefit the most from CH care and the best skill mix to deliver this care.Methods: We analysed all elderly patients discharged from the CHs of Emilia-Romagna, Italy. CH skill mix and care processes were collected with an ad hoc survey. The primary outcome was improvement in the Barthel index (BI) on discharge. Hierarchical regression analysis was performed to test the associations under study.Results: 53% of the patients had a BI improvement >= 10. After adjusting for the diverse case mix of the patients, no significant association was found between CH characteristics and BI improvement. Patient characteristics explained only a portion of the variability in CH performance.Discussion: Heterogeneity in case mix reflects the nature of CHs, which play context-specific roles as integrators between primary care services and hospitals. Residual variability in BI improvement rates across CHs might be attributed to aspects of care not detected in our survey.Conclusions: More research is needed to study the impact of CH skill mix and care processes on patient outcomes

Pronounced structural and functional damage in early adult pediatric-onset multiple sclerosis with no or minimal clinical disability

Pediatric-onset multiple sclerosis (POMS) may represent a model of vulnerability to damage occurring during a period of active maturation of the human brain. Whereas adaptive mechanisms seem to take place in the POMS brain in the short-medium term, natural history studies have shown that these patients reach irreversible disability, despite slower progression, at a significantly younger age than adult-onset MS (AOMS) patients. We tested for the first time whether significant brain alterations already occurred in POMS patients in their early adulthood and with no or minimal disability (n = 15) in comparison with age- and disability-matched AOMS patients (n = 14) and to normal controls (NC, n = 20). We used a multimodal MRI approach by modeling, using FSL, voxelwise measures of microstructural integrity of white matter tracts and gray matter volumes with those of intra- and internetwork functional connectivity (FC) (analysis of variance, p â\u89¤ 0.01, corrected for multiple comparisons across space). POMS patients showed, when compared with both NC and AOMS patients, altered measures of diffusion tensor imaging (reduced fractional anisotropy and/or increased diffusivities) and higher probability of lesion occurrence in a clinically eloquent region for physical disability such as the posterior corona radiata. In addition, POMS patients showed, compared with the other two groups, reduced long-range FC, assessed from resting functional MRI, between default mode network and secondary visual network, whose interaction subserves important cognitive functions such as spatial attention and visual learning. Overall, this pattern of structural damage and brain connectivity disruption in early adult POMS patients with no or minimal clinical disability might explain their unfavorable clinical outcome in the long term

Infermieristica Nefrologica: Competenze Assistenziali Generali e Specifiche

L'articolo esprime la posizione attuale dell'associazione EDTNA/ERCA Filiale Italiana rispetto al dibattito sulle competenze infermieristiche avanzate – o specialistiche - in atto nella comunità medico-sanitaria nazionale. Facendo riferimento al modello ISFOL, come strumento della definizione delle competenze nel mondo del lavoro, nel territorio europeo ed oltre, il modello viene declinato per il mondo sanitario ed ulteriomente capillarizzato per le aree di assistenza infermieristica nefrologica. Il modello riconosce competenze di base, competenze di settore, trasversali e specifiche. Attraverso questo percorso, da generico e a specifico, vengono riconosciute 6 aree specifiche di assistenza nefrologica (ambulatorio, degenza, dialisi peritoneale, emodialisi, area critica, trapianti) ed in ognuna di esse vengono elencate le competenze di pertinenza infermieristica (sapere e saper fare, saper essere). L'elaborato si propone come strumento di riferimento, di confronto e di stimolo per le varie realtà operative nazionale dell'assistenza nefrologica

Guiding water into carbon nanopipes with the aid of bipolar electrochemistry

Microfluidics and Nanofluidics, 1(3): pp. 284-288. Retrieved September 19, 2006 from http://nano.materials.drexel.edu/publications.html.The targeted bipolar electrodeposition of polypyrrole was carried out onto the tips of hydrophilic carbon nanopipes. By aligning an external electric field relative to the nanopipes, the deposition of polypyrrole onto selected ends could be achieved without physically contacting the nanopipes. After deposition, carbon nanopipes with both partially open and fully blocked tips were found. Experiments conducted in an environmental scanning electron microscope showed that water enters the nanopipes through the tip with polypyrrole due to the higher hydrophilicity of the polymer compared to the tube walls. As a result, it was possible to guide the entry of water from a specific end of the tube and fill the tube from the selected side. Condensation experiments conducted on nanopipes with polypyrrole on both tips shows the difference in hydrophilicity of the nanopipes compared to the polypyrrole. The ability to selectively control the site of condensation and uptake of fluid by carbon nanotubes or nanopipes is very important for the development of nanotube-based nanofluidic devices

Imaging of liquid crystals confined in carbon nanopipes

Applied Physics Letters, 89(4), 3. http://dx.doi.org/10.1063/1.2240739This letter investigates the unexplored phenomenon of the wetting of liquid crystals inside carbon nanopipes. Carbon nanopipes are similar to carbon nanotubes but are open ended with straight walls. Using environmental scanning electron microscopy, the authors have observed liquid crystal menisci inside the nanopipes. Raman spectroscopy was used to confirm the presence of liquid crystals confined in the nanopipes and verify the physical interaction between the two materials. In addition, observations from reflection polarized optical microscopy experiments suggest the use of liquid crystals inside carbon nanotubes to develop electro-optic switches

Relevance of brain lesion location to cognition in relapsing multiple sclerosis

OBJECTIVE: To assess the relationship between cognition and brain white matter (WM) lesion distribution and frequency in patients with relapsing-remitting multiple sclerosis (RR MS). METHODS: MRI-based T2 lesion probability map (LPM) was used to assess the relevance of brain lesion location for cognitive impairment in a group of 142 consecutive patients with RRMS. Significance of voxelwise analyses was p<0.05, cluster-corrected for multiple comparisons. The Rao Brief Repeatable Battery was administered at the time of brain MRI to categorize the MS population into cognitively preserved (CP) and cognitively impaired (CI). RESULTS: Out of 142 RRMS, 106 were classified as CP and 36 as CI. Although the CI group had greater WM lesion volume than the CP group (p = 0.001), T2 lesions tended to be less widespread across the WM. The peak of lesion frequency was almost twice higher in CI (61% in the forceps major) than in CP patients (37% in the posterior corona radiata). The voxelwise analysis confirmed that lesion frequency was higher in CI than in CP patients with significant bilateral clusters in the forceps major and in the splenium of the corpus callosum (p<0.05, corrected). Low scores of the Symbol Digit Modalities Test correlated with higher lesion frequency in these WM regions. CONCLUSIONS: Overall these results suggest that in MS patients, areas relevant for cognition lie mostly in the commissural fiber tracts. This supports the notion of a functional (multiple) disconnection between grey matter structures, secondary to damage located in specific WM areas, as one of the most important mechanisms leading to cognitive impairment in MS