WTC2005-64215 MULTI SCALE STUDY OF ABRASION SIGNATURE BY 2D WAVELET DECOMPOSITION

Abstract The high performance of industrial applications, requires increasingly technical functional surfaces, particulary from the point of view of topography and microtexture. To study the effect of abrasive finishing in a wide range of wavelengths of surface topography, we developed a multi-scale approach, based on the decomposition of surface topography by 2D continuous wavelet transform. This new approach made it possible to determine the multi-scale transfer function of machining by abrasion for each stage of finishing. The methodology can be extended to characterize abrasive wear in a wide range of scales. Introduction The use of hard turning as a finishing process is often limited by surface quality requirements in the case of component surfaces designed to support high stress. Low roughness can be achieved only at low feed rates. Moreover, tool wear leads to a deterioration in the surface after the tool has been in use for some time. A subsequent finishing operation can both increase the range of permissible feed rates towards higher values and prolong the life of the tool's cutting edge. One finishing operation whose working principle suits especially well for combination with hard turning is the belt grinding. This abrasive operation makes it possible to create surfaces of high quality, with specific functions like mechanical bearing pressure, sealing of metal joints, friction and noise of friction. Abrasive finishing modifies the surface topography in a wide range of scales of roughness and waviness, and consequently modifies the functionality of the surface in terms of bearing area, local plasticity and durability. This paper introduces a new approach based on a multi-scale decomposition of the surface topography before and after finishing by using a 2D continuous wavelet decomposition. This approach makes it possible to follow the effect of the various stages of finishing on a wide range of wavelengths, and makes it possible to determine th

Preliminary Investigation of the Frictional Response of Reptilian Shed Skin

Developing deterministic surfaces relies on controlling the structure of the rubbing interface so that not only the surface is of optimized topography, but also is able to self-adjust its tribological behaviour according to the evolution of sliding conditions. In seeking inspirations for such designs, many engineers are turning toward the biological world to correlate surface structure to functional behavior of bio-analogues. From a tribological point of view, squamate reptiles offer diverse examples where surface texturing, submicron and nano-scale features, achieve frictional regulation. In this paper, we study the frictional response of shed skin obtained from a snake (Python regius). The study employed a specially designed tribo-acoustic probe capable of measuring the coefficient of friction and detecting the acoustical behavior of the skin in vivo. The results confirm the anisotropy of the frictional response of snakes. The coefficient of friction depends on the direction of sliding: the value in forward motion is lower than that in the backward direction. In addition it is shown that the anisotropy of the frictional response may stem from profile asymmetry of the individual fibril structures present within the ventral scales of the reptil

Trajectories of early secondary insults correlate to outcomes of traumatic brain injury: results from a large, single centre, observational study

Background: Secondary insults (SI), such as hypotension, hypoxia, and intracranial hypertension frequently occur after traumatic brain injury (TBI), and have a strong impact on patients\u2019 clinical outcomes. The aim of this study is to examine the trajectories of SI from the early phase of injury in the prehospital setting to hospital admission in a cohort of TBI patients. Methods: This is a retrospective, observational, single centre study on consecutive patients admitted from 1997 to 2016 to the Neuro Intensive Care Unit (NICU) at San Gerardo Hospital, in Monza, Italy. Trajectories of SI from the prehospital to hospital settings were defined as \u201csustained\u201d, \u201cresolved\u201d, \u201cnew event\u201d, and \u201cnone\u201d. Univariate and multivariate logistic regression analyses were performed to correlate SI trajectories to a 6-months outcome. Results: Nine hundred sixty-seven patients were enrolled in the final analysis. About 20% had hypoxic or hypotensive events and 30.7% of patients had pupillary abnormalities. Hypotension and hypoxia were associated with an unfavourable outcome when \u201csustained\u201d and \u201cresolved\u201d, while pupillary abnormalities were associated with a poor outcome when \u201csustained\u201d and as \u201cnew events\u201d. After adjusting for confounding factors, 6-month mortality strongly correlated with \u201csustained\u201d hypotension (OR 11.25, 95% CI, 3.52\u201335.99), \u201csustained\u201d pupillary abnormalities (OR 2.8, 95% CI, 1.51\u20135.2) and \u201cnew event\u201d pupillary abnormalities (OR 2.8, 95% CI, 1.16\u20136.76). Conclusions: After TBI, sustained hypotension and pupillary abnormalities are important determinants for patients\u2019 outcomes. Early trajectories define the dynamics of SI and contribute to a better understanding of how early recognition and treatments in emergency settings could impact on 6-month outcomes and mortality

Modificazioni dei livelli di acido arachidonico e vitamina A in relazione alla attività anticancerogena attribuita all'apporto alimentare di burro naturalmente arricchito in acido linoleico a dieni coniugati (CLA)

Considerable attention has recently been directed to the naturally occurring trace fatty acid conjugated linoleic acid (CLA), based on its dual ability to act both as a preventive and therapeutic agent in a number of rodent and human tumor model systems. CLA, which is synthesized by rumen bacteria, is found in meat and dairy products, and is of particular interest since it is effective at low levels in the diet. Our research interest is to explore whether the mechanism of the anticarcinogenic activity of CLA may be reconductible to its metabolism and influence on tissue lipid metabolism. CLA is a polyunsaturated fatty acid (PUFA) with two singular properties: 1) Its metabolism is alike that of linoleic acid and thus competes with the latter for the elongation and desaturation enzyme systems, leading on one hand to a decreased generation of eicosatrienoic and arachidonic acids for eicosanoid synthesis, and on the other to a replacement of the natural substrates with CLA metabolites known to inhibit the cyclooxigenase (COX) and lipooxygenase (LPOX) pathways; and 2) It increases the retinol content of different tissues, an effect that may be due to β-oxidation of CLA by peroxisomes with consequent activation of peroxisome proliferator activated receptor a (PPARα). The effects of CLA on eicosanoid synthesis may be the key factor of a common mechanism underlying its pleiotropic activities, and our current working hypothesis is that this factor along with tissue retinol increase, mediate the anticarcinogenic action of CLA

Ensuring editorial continuity and quality of science during the COVID-19 storm: the ICM experience

We analyzed the manuscript submissions to ICM and the responses of the invited reviewers from January to April 2020, and compared the findings of peer-review activity with the same time span in 2019. From January 1st to April 30th 2020, there was a considerable increase in submissions (1201 total submissions, 617 of which were COVID-related) over the comparable time in 2019 (554 total submissions). In both cases, the average percentage of advanced rejections was around 60.In 2019, 180 manuscripts were sent to 1.271 reviewers. In the comparable period of 2020, 296 manuscripts were sent out to 1.741 reviewers. Despite the rapid and massive increase in workload for intensive care health professionals due to the ‘Corona crisis’ our findings suggest that, overall, the peer-review activity in high-quality intensive care journals has not suffered a crisis and does guarantee the continuity of one of the columns of quality in science

Changes in upper airways microbiota in ventilator-associated pneumonia

Background: The role of upper airways microbiota and its association with ventilator-associated pneumonia (VAP) development in mechanically ventilated (MV) patients is unclear. Taking advantage of data collected in a prospective study aimed to assess the composition and over-time variation of upper airway microbiota in patients MV for non-pulmonary reasons, we describe upper airway microbiota characteristics among VAP and NO-VAP patients. Methods: Exploratory analysis of data collected in a prospective observational study on patients intubated for non-pulmonary conditions. Microbiota analysis (trough 16S-rRNA gene profiling) was performed on endotracheal aspirates (at intubation, T0, and after 72 h, T3) of patients with VAP (cases cohort) and a subgroup of NO-VAP patients (control cohort, matched according to total intubation time). Results: Samples from 13 VAP patients and 22 NO-VAP matched controls were analyzed. At intubation (T0), patients with VAP revealed a significantly lower microbial complexity of the microbiota of the upper airways compared to NO-VAP controls (alpha diversity index of 84 ± 37 and 160 ± 102, in VAP and NO_VAP group, respectively, p-value < 0.012). Furthermore, an overall decrease in microbial diversity was observed in both groups at T3 as compared to T0. At T3, a loss of some genera (Prevotella 7, Fusobacterium, Neisseria, Escherichia-Shigella and Haemophilus) was found in VAP patients. In contrast, eight genera belonging to the Bacteroidetes, Firmicutes and Fusobacteria phyla was predominant in this group. However, it is unclear whether VAP caused dysbiosis or dysbiosis caused VAP. Conclusions: In a small sample size of intubated patients, microbial diversity at intubation was less in patients with VAP compared to patients without VAP

International prospective observational study on intracranial pressure in intensive care (ICU): the SYNAPSE-ICU study protocol.

Intracranial pressure (ICP) monitoring is commonly used in neurocritical care patients with acute brain injury (ABI). Practice about indications and use of ICP monitoring in patients with ABI remains, however, highly variable in high-income countries, while data on ICP monitoring in low and middle-income countries are scarce or inconsistent. The aim of the SYNAPSE-ICU study is to describe current practices of ICP monitoring using a worldwide sample and to quantify practice variations in ICP monitoring and management in neurocritical care ABI patients. The SYNAPSE-ICU study is a large international, prospective, observational cohort study. From March 2018 to March 2019, all patients fulfilling the following inclusion criteria will be recruited: age >18 years; diagnosis of ABI due to primary haemorrhagic stroke (subarachnoid haemorrhage or intracranial haemorrhage) or traumatic brain injury; Glasgow Coma Score (GCS) with no eye opening (Eyes response=1) and Motor score ≤5 (not following commands) at ICU admission, or neuro-worsening within the first 48 hours with no eye opening and a Motor score decreased to ≤5. Data related to clinical examination (GCS, pupil size and reactivity, Richmond Agitation-Sedation Scale score, neuroimaging) and to ICP interventions (Therapy Intensity Levels) will be recorded on admission, and at day 1, 3 and 7. The Glasgow Outcome Scale Extended (GOSE) will be collected at discharge from ICU and from hospital and at 6-month follow-up. The impact of ICP monitoring and ICP-driven therapy on GOSE will be analysed at both patient and ICU level. The study has been approved by the Ethics Committee 'Brianza' at the Azienda Socio Sanitaria Territoriale (ASST)-Monza (approval date: 21 November 2017). Each National Coordinator will notify the relevant ethics committee, in compliance with the local legislation and rules. Data will be made available to the scientific community by means of abstracts submitted to the European Society of Intensive Care Medicine annual conference and by scientific reports and original articles submitted to peer-reviewed journals. NCT03257904