Search results for "Tact"
showing 10 items of 1313 documents
Lateral force microscopy of multiwalled carbon nanotubes
2009
Carbon nanotubes are usually imaged with the atomic force microscope (AFM) in non-contact mode. However, in many applications, such as mechanical manipulation or elasticity measurements, contact mode is used. The forces affecting the nanotube are then considerable and not fully understood. In this work lateral forces were measured during contact mode imaging with an AFM across a carbon nanotube. We found that, qualitatively, both magnitude and sign of the lateral forces to the AFM tip were independent of scan direction and can be concluded to arise from the tip slipping on the round edges of the nanotube. The dependence on the normal force applied to the tip and on the ratio between nanotub…
Depletion of carbon nanotube depositions and tube realignment in the spreading of sessile drops
2015
Abstract We studied spreading of drops of water and dilute alcohol on multiwall carbon nanotube (MWNT) depositions. These deposits consisted of individual arc-discharge synthesized MWNTs and irregular amorphous carbon nanoparticles on hydrophilically rendered silicon substrates. The mobile circular contact line of a spreading drop created an annular shape on the deposit, where some of the MWNTs and the amorphous nanoparticles in particular were largely depleted. The effect was strongly dependent on the hydrophilicity of the substrate. Most of the MWNTs were not only left within the annuli, but were also apparently reoriented by their interaction with the passing contact line. Our results im…
Determination of the electroactive area of graphite+polyethylene composite electrodes. Uncompensated resistance effects and convolution analysis of c…
1998
In this work, it is shown how the convolution analysis of chronoamperograms permits the observation of the uncompensated resistance and the natural convection effects on the electrochemical response of potassium ferrocyanide. The uncompensated resistance causes the current intensity to follow the Cottrell equation only after a certain critical time. The convolution of chronoamperograms worked out at different integration times shows a maximum when this time is long enough. The classical diffusion equations cannot explain this phenomenon themselves. The development of this maximum associated with the natural convection is discussed. If both these factors, the ohmic drop and the natural conve…
Sanitizing food contact surfaces by the use of essential oils
2018
Chemical sanitizers continue to be widely used by the food industry to disinfect food contact surfaces. However, as some chemical disinfectants have been reported to produce unhealthy by-products, alternative and natural compounds need to be investigated. To this end, nine essential oils (EOs) were screened to develop a natural sanitizing solution (SAN) for disinfecting food contact surfaces. Once extracted, their antimicrobial activity and chemical composition were determined. An exploratory multivariate approach was used to investigate the relationships between the chemical and microbiological data sets. Among the tested EOs, Thymbra capitata EO, containing up to 93.31% oxygenated monoter…
Intravesical bleomycin in bladder tumour prophylaxis.
1986
The authors have evaluated the efficacy, tolerability and systemic absorption of bleomycin administered by intravesical route in the prophylaxis of recurrences of superficial vesical tumours after endoscopic resection (TUR). Thirty mg of bleomycin dissolved in 30 ml of saline solution were instilled in the bladder once a week for the first month and then once a month for 12 months. The instilled fluid was held in the bladder for 1 hour. The systemic absorption of the drug was evaluated by a microbiological assay of bleomycin in plasma and in the perfusion liquid recovered from the bladder. Fifteen patients were treated; most had a long history of multiple recurrent tumours despite previous …
Neuronavigation-guided biopsy for differential diagnosis of pseudotumoral demyelinating brain lesions
2014
Abstract Marburg's disease (MD) is an extremely rare and aggressive form of multiple sclerosis (MS). In some cases, MD presents with tumefactive demyelinating lesions with a “tumor-like” appearance in MRI images, for which it may be difficult to achieve a form of differential diagnosis between definitive tumors or abscesses. Here we report a case of MD histopathologically confirmed after neuronavigationguided biopsy. Postoperative course was uneventful and following discharge, the patient attended outpatient follow-up appointments and received i.v. cyclophopsphamide, achieving progressive clinical remission. A nine-month follow-up brain MRI scan with gadolinium showed no signs of progressin…
Phospholipase A2 and arachidonic acid: a common link in the generation of the eosinophil chemotactic factor (ECF) from human PMN by various stimuli.
1980
An eosinophil chemotactic factor (ECF) of low molecular weight can be generated and released from human polymorphonuclear neutrophils by the calcium ionophore, phagocytosis of zymosan particles, arachidonic acid, and phospholipase A2. Since the activation of cells by the ionophore and during the phagocytic event leads to phospholipid turnover, with the subsequent generation of arachidonic acid, it is reasonable that phospholipase A2 represents the common link for ECF production. The kinetics of ECF release by phospholipase A2 is similar to the pattern observed with the various stimuli. After a rapid rise in activity a decline occurred at later times of secretion, suggesting a mechanism of i…
Survey of Italian pediatricians’ perspectives and knowledge about neonatal screening
2015
Background The goal of newborn screening is early identification of babies with a high risk for disorders that may not be clinically evident at birth, but have severe consequences if untreated. New insight into inherited diseases and the ability to test for numerous diseases using new technique such as tandem mass spectrometry have made it practical to greatly expand the number of conditions tested. The expanded neonatal screening is now available and relatively simple, but this represents only a part of the picture. Positive results require follow-up confirmation. Most disorders screened require confirmatory biochemical or genetic tests and specialist visits. An efficient system is needed …
Ni-Cr based dental alloys; Ni release, corrosion and biological evaluation.
2011
Abstract In the last years the dental alloy market has undergone dramatic changes for reasons of economy and biocompatibility. Nickel based alloys have become widely used substitute for the much more expensive precious metal alloys. In Europe the prevalence of nickel allergy is 10–15% for female adults and 1–3% for male adults. Despite the restrictions imposed by the EU for the protection of the general population in contact dermatitis, the use of Ni–Cr dental alloys is on the increase. Some questions have to be faced regarding the safety risk of nickel contained in dental alloys. We have collected based on many EU markets, 8 Ni–Cr dental alloys. Microstructure characterization, corrosion r…
Economic analysis of the scale-up and implantation of a hollow fibre membrane contactor plant for nitrogen recovery in a full-scale wastewater treatm…
2021
[EN] Nitrogen recovery technologies such as the hollow fibre membrane contactor are now being developed. However, an economic analysis is needed prior to their full-scale application in wastewater treatment plants. The aim of this study was to analyse the economic and environmental aspects of scaling-up this method. To achieve it, a full-scale 40,000 m3·day¿1-wastewater treatment plant influent flow rate was simulated jointly with a membrane contactor plant to evaluate the minimum costs of optimum operating conditions of membrane contactors (pH, feed flow rate and membrane surface). The optimum conditions for treating 600 m3·day¿1 of reject water was found to be 10 pH, 0.08 m3·s¿1 feed flow…