A CubeSat-class micropropulsion system is being developed at the Aerospace Plasma Laboratory, Technion-Israel Institute of Technology, called the inline-screw-feeding vacuumarc thruster (ISF-VAT). ...The ISF-VAT couples a conventional VAT triggerless ignition geometry with an active feeding system that mechanically drives the cathode propellant in a periodic helical motion. The thruster performance is found to be highly regular for at least 700000 pulses, ≈12 h of continuous operation, with good pulse to pulse repeatability. The measured average thrust-to-power ratio is ≈3 μN/W. Observations of the cathode and insulator erosion patterns show that while the cathode electrode geometry is maintained by the feeding system, the ceramic insulator is also being consumed. The maximum insulator erosion rate was determined to be ≈1/7 of the cathode consumption rate. The thruster lifetime is, therefore, determined by the length of the insulator.
BackgroundOur production unit realises more than 35 000 cytotoxic drug preparations per year in an isolator chamber (IC). The control method is done by in-process gravimetric analysis coupled with ...scan identification, led by software with interactive instructions. The balances are certified once a year, yet outside the IC. Indeed, turbulent airflow could impact the scales’ measurements. The accepted errors percentages are a function of the volumes weighted.PurposeAfter software development and setup, we need to validate this control method with the two components: the weighing scales and the software.Material and methodsFor the weighting scales, a qualification was made inside and outside the IC with standard weights. For the validation the tests performed were fidelity, accuracy and eccentricity. Then, a comparison to visual control was performed to evaluate the bias of the balance. Six syringes with different volumes were made and then verified by a third person. Next, they were weighed 15 times to obtain the total error. For the software, a method is being developed to analyse the specificity and the sensitivity. For the specificity, an extraction of the software was done to study the forced steps (the steps refused by the software but accepted by the pharmacist because of the correct volume read) over a period of 6 months.ResultsThe metrological tests enable to qualify the balances. The bias of the weighing scales fluctuates between 0.94% and 4.40%. Over 6 months, 15 227 preparations were realised with a total of 1 89 334 steps including 49 180 weighing steps. Among those, there were 2023 forced steps (4.1%). The most forced cytotoxic molecules were identified. The two most forced stages were the weighing of the syringe with cytotoxic (41%) and of the final pouch (23%). The 50 ml syringe is responsible for 41% of this forced stage and, in 85% of the cases, it is because the volume to collect has a decimal value.ConclusionConcerning the sensitivity, a method is elaborated to determine the rate of the false negatives with a fake cytotoxic preparations plan and calculated weighing errors. Our method validation plan is complete with the validation of the two components: precision scale and software.References and/or acknowledgementsNo conflict of interest.
1ISG-014 Iso 9001 certification: customer focus Cayre, F; Baillet, L; Fercocq, C ...
European journal of hospital pharmacy. Science and practice,
03/2018, Letnik:
25, Številka:
Suppl 1
Journal Article
Recenzirano
Odprti dostop
BackgroundAs part of the ISO 9001 certification process of our hospital’s centralised cytotoxic preparation unit, customer focus is essential for monitoring and continuously improving quality. An ...annual satisfaction survey was carried out among the physicians and nurses of our hospital (14 000 annual preparations) and the pharmacists of the five health institutions which subcontracted the preparation of their cytotoxic drugs to our unit (22 500 annual preparations).PurposeTo evaluate the adequacy of the satisfaction survey methodology for the annual monitoring of quality and customer satisfaction.Material and methodsThree separate questionnaires (physicians, nurses, pharmacists) were sent to the concerned staff to assess the past year. The items addressed were overall satisfaction, communication, overall circuit quality, clinical pharmacy activities, preparations’ quality, transport and delivery, billing and management of customer claims. For each item, a score or a rate of satisfaction was calculated and each centre’s specific problems were identified. A personalised report detailing the causes and remedial actions was then sent to each health institution.ResultsThirty-seven people participated to the survey (including 75% of the pharmacists surveyed and 47% of the physicians surveyed). The overall satisfaction grade was 17.4/20 and the satisfaction rates were: 99.5% (communication); 94.6% (circuit); 94.3% (clinical pharmacy); 98.3% (preparations); 89.5% (transport/delivery); 100% (billing) and 99.1% (customer claims). The remedial actions implemented in our hospital were the preparation in advance of standardised doses of rituximab to limit patients’ wait and the creation of several quality indicators, including the time between the demand and the delivery of a preparation. For the health institutions in subcontracts for their preparations, a quality indicator has been set up to monitor the conformity of the departure times of deliveries and the carrier company has been replaced for one of them.ConclusionThe methodology used (format of the questionnaires, items addressed, staff surveyed, rating modalities) allows the standardisation of answers and their exploitation. Repeated annually, this satisfaction survey will permit an objective comparison of the results and a follow-up of the evolution of quality and customer satisfaction.No conflict of interest
The development of antifouling strategies in seawater requires knowledge of the physico-chemical properties of the cell surfaces of early adherent bacteria. The hydrophilic, electrostatic and the ...Lewis acid-base cell surface properties of eleven marine bacteria were characterized. Although these bacteria adhered to a hydrophilic support immersed for 3 and 6 h, they presented various physico-chemical properties. Eleven strains possessed a hydrophilic surface and five a hydrophobic surface. Although the majority of the bacteria presented an electron-donating character, some could not generate Lewis acid-base interactions with the support. On the other hand, all strains possessed an isoelectric point ranging from 2.2 to 3.4 and were negatively charged at the pH of seawater. Hydrophilicity was a preponderant property among these bacteria, but other properties should not be ignored. The development of new antifouling paints must take account all the possible interaction levels used by the bacteria to adhere to an immersed surface.
•A novel in silico model of Organophosphorus (OP)-induced neuronal toxicity is set up.•This model enables predicting effect of drugs on OP-induced neuronal hyperexcitability.•The predicted effects of ...atropine, memantine, their combination are validated in vivo.•The use of the in silico modeling early in the antidote screening process is proposed.
Exposure to organophosphorus (OP) compounds, either pesticides or chemical warfare agents, represents a major health problem. As potent irreversible inhibitors of cholinesterase, OP may induce seizures, as in status epilepticus, and occasionally brain lesions. Although these compounds are extremely toxic agents, the search for novel antidotes remains extremely limited. In silico modeling constitutes a useful tool to identify pharmacological targets and to develop efficient therapeutic strategies. In the present work, we developed a new in silico simulator in order to predict the neurotoxicity of irreversible inhibitors of acetyl- and/or butyrylcholinesterase (ChE) as well as the potential neuroprotection provided by antagonists of cholinergic muscarinic and glutamate N-methyl-d-aspartate (NMDA) receptors. The simulator reproduced firing of CA1 hippocampal neurons triggered by exposure to paraoxon (POX), as found in patch-clamp recordings in in vitro mouse hippocampal slices. In the case of POX intoxication, it predicted a preventing action of the muscarinic receptor antagonist atropine sulfate, as well as a synergistic action with the non-competitive NMDA receptor antagonist memantine. These in silico predictions relative to beneficial effects of atropine sulfate combined with memantine were recapitulated experimentally in an in vivo model of POX in adult male Swiss mice using electroencephalic (EEG) recordings. Thus, our simulator is a new powerful tool to identify protective therapeutic strategies against OP central effects, by screening various combinations of muscarinic and NMDA receptor antagonists.
To determine whether power-velocity relationships obtained on a nonisokinetic cycle ergometer could be related to muscle fibre type composition, ten healthy specifically trained subjects (eight men ...and two women) performed brief periods of maximal cycling on a friction loaded cycle ergometer. Frictional force and flywheel velocity were recorded at a sampling frequency of 200 Hz. Power output was computed as the product of velocity and inertial plus frictional forces. Force, velocity and power were averaged over each down stroke. Muscle fibre content was determined by biopsy of the vastus lateralis muscle. Maximal down stroke power 14.36 (SD 2.37)W.kg-1 and velocity at maximal power 120 (SD 8) rpm were in accordance with previous results obtained on an isokinetic cycle ergometer. The proportion of fast twitch fibres expressed in terms of cross sectional area was related to optimal velocity (r = 0.88, P < 0.001), to squat jump performance (r = 0.78, P < 0.01) and tended to be related to maximal power expressed per kilogram of body mass (r = 0.60, P = 0.06). Squat jump performance was also related to cycling maximal power. expressed per kilogram of body mass (r = 0.87, P < 0.01) and to optimal velocity (r = 0.86, P < 0.01). All these data suggest that the nonisokinetic cycle ergometer is a good tool with which to evaluate the relative contribution of type II fibres to maximal power output. Furthermore, the strong correlation obtained demonstrated that optimal velocity, when related to training status, would appear to be the most accurate parameter to explore the fibre composition of the knee extensor muscle.
The effects of 4 weeks of endurance training in conditions of normoxia or hypoxia on muscle characteristics and blood lactate responses after a 5-min constant-load exercise (CLE) at 90% of the power ...corresponding to the maximal oxygen uptake were examined at sea-level in 13 sedentary subjects. Five subjects trained in normobaric hypoxia (HT group, fraction of oxygen in inspired gas = 13.2%), and eight subjects trained in normoxia at the same relative work rates (NT group). The blood lactate recovery curves from the CLE were fitted to a biexponential time function: La(t) = La(0) + A1(1 - e- gamma 1.t) + A2(1 - e- gamma 2.t), where the velocity constants gamma 1 and gamma 2 denote the lactate exchange and removal abilities, respectively, A1 and A2 are concentration parameters that describe the amplitudes of concentration variations in the space represented by the arterial blood, La(t) is the lactate concentration at time t, and La(0) is the lactate concentration at the beginning of recovery from CLE. Before training, the two groups displayed the same muscle characteristics, blood lactate kinetics after CLE, and gamma 1 and gamma 2 values. Training modified their muscle characteristics, blood lactate kinetics and the parameters of the fits in the same direction, and proportions among the HT and the NT subjects. Endurance training increased significantly the capillary density (by 31%), citrate synthase activity (by 48%) and H isozyme proportion of lactate dehydrogenase (by 24%), and gamma 1 (by 68%) and gamma 2 (by 47%) values. It was concluded that (1) endurance training improves the lactate exchange and removal abilities estimated during recovery from exercises performed at the same relative work rate, and (2) training in normobaric hypoxia results in similar effects on lactate exchange and removal abilities to training in normoxia performed at the same relative work rates. These results, which were obtained non-invasively in vivo in humans during recovery from CLE, are comparable to those obtained in vitro or by invasive methods during exercise and subsequent recovery.
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