The role of dexmedetomidine in neurosurgery

Dexmedetomidine can be used for sedation and analgesia and has been approved for this use by the European Medicines Agency since 2017. It causes an arousable state of sedation, which is beneficial during neurosurgical procedures that require the patient to cooperate with neurological tests (i.e. tumor surgery or implantation of deep brain stimulators). During procedures where monitoring of somatosensory evoked potentials and/or motor evoked potentials is required, dexmedetomidine can be used as an adjunct to general anesthesia with GABAergic drugs to decrease the dose of the latter when these drugs impair the monitoring signals. The use of dexmedetomidine has also been associated with neuroprotective effects and a decreased incidence of delirium, but studies confirming these effects in the peri-operative (neuro-) surgical setting are lacking. Although dexmedetomidine does not cause respiratory depression, its hemodynamic effects are complex and careful patient selection, choice of dose, and monitoring must be performed. (c) 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/)

Quasiparticle relaxation in optically excited high-Q superconducting resonators

The quasiparticle relaxation time in superconducting films has been measured as a function of temperature using the response of the complex conductivity to photon flux. For tantalum and aluminium, chosen for their difference in electron-phonon coupling strength, we find that at high temperatures the relaxation time increases with decreasing temperature, as expected for electron-phonon interaction. At low temperatures we find in both superconducting materials a saturation of the relaxation time, suggesting the presence of a second relaxation channel not due to electron-phonon interaction.Comment: 4 pages, 3 figure

Enhancement of quasiparticle recombination in Ta and Al superconductors by implantation of magnetic and nonmagnetic atoms

The quasiparticle recombination time in superconducting films, consisting of the standard electron-phonon interaction and a yet to be identified low temperature process, is studied for different densities of magnetic and nonmagnetic atoms. For both Ta and Al, implanted with Mn, Ta and Al, we observe an increase of the recombination rate. We conclude that the enhancement of recombination is not due to the magnetic moment, but arises from an enhancement of disorder.Comment: 4 pages, 4 figure

Compressed sensing quantum process tomography for superconducting quantum gates

We apply the method of compressed sensing (CS) quantum process tomography (QPT) to characterize quantum gates based on superconducting Xmon and phase qubits. Using experimental data for a two-qubit controlled-Z gate, we obtain an estimate for the process matrix $\chi$ with reasonably high fidelity compared to full QPT, but using a significantly reduced set of initial states and measurement configurations. We show that the CS method still works when the amount of used data is so small that the standard QPT would have an underdetermined system of equations. We also apply the CS method to the analysis of the three-qubit Toffoli gate with numerically added noise, and similarly show that the method works well for a substantially reduced set of data. For the CS calculations we use two different bases in which the process matrix $\chi$ is approximately sparse, and show that the resulting estimates of the process matrices match each ther with reasonably high fidelity. For both two-qubit and three-qubit gates, we characterize the quantum process by not only its process matrix and fidelity, but also by the corresponding standard deviation, defined via variation of the state fidelity for different initial states.Comment: 16 pages, 11 figure

Hypotension during propofol sedation for colonoscopy:an exploratory analysis

BACKGROUND: Intraoperative and postoperative hypotension occur commonly and are associated with organ injury and poor outcomes. Changes in arterial blood pressure (BP) during procedural sedation are not well described. METHODS: Individual patient data from five trials of propofol sedation for colonoscopy and a clinical database were pooled and explored with logistic and linear regression. A literature search and focused meta-analysis compared the incidence of hypotension with propofol and alternative forms of procedural sedation. Hypotensive episodes were characterised by the original authors' definitions (typically systolic BP 5 min, and in 89 (23%) the episodes exceeded 10 min. Meta-analysis of 18 RCTs identified an increased risk ratio for the development of hypotension in procedures where propofol was used compared with the use of etomidate (two studies; n=260; risk ratio [RR] 2.0 [95% confidence interval: 1.37–2.92]; P=0.0003), remimazolam (one study; n=384; RR 2.15 [1.61–2.87]; P=0.0001), midazolam (14 studies; n=2218; RR 1.46 [1.18–1.79]; P=0.0004), or all benzodiazepines (15 studies; n=2602; 1.67 [1.41–1.98]; P<0.00001). Hypotension was less likely with propofol than with dexmedetomidine (one study; n=60; RR 0.24 [0.09–0.62]; P=0.003). CONCLUSIONS: Hypotension is common during propofol sedation for colonoscopy and of a magnitude and duration associated with harm in surgical patients

Food neophobia and mealtime food consumption in 4-5 year old children.

Background: Previous research has documented a negative association between maternal report of child food neophobia and reported frequency of consumption of fruit, vegetables, and meat. This study aimed to establish whether neophobia is associated with lower intake of these food types in naturalistic mealtime situations. Methods: One hundred and nine parents of 4–5 year olds completed questionnaires which included a six-item version of the Child Food Neophobia Scale (CFNS). The children took part in a series of 3 test lunch meals at weekly intervals at school at which they were presented with: chicken, cheese, bread, cheese crackers, chocolate biscuits, grapes and tomatoes or carrot sticks. Food items served to each child were weighed before and after the meal to assess total intake of items in four categories: Fruit and vegetables, Protein foods, Starchy foods and Snack foods. Pearson Product Moment Correlations and independent t tests were performed to examine associations between scores on the CFNS and consumption during lunches. Results: Neophobia was associated with lower consumption of fruit and vegetables, protein foods and total calories, but there was no association with intake of starch or snack foods. Conclusion: These results support previous research that has suggested that neophobia impacts differentially on consumption of different food types. Specifically it appears that children who score highly on the CFNS eat less fruit, vegetables and protein foods than their less neophobic peers. Attempts to increase intake of fruit, vegetables and protein might usefully incorporate strategies known to reduce the neophobic response

What's New in Intravenous Anaesthesia?:New Hypnotics, New Models and New Applications

New anaesthetic drugs and new methods to administer anaesthetic drugs are continually becoming available, and the development of new PK-PD models furthers the possibilities of using arget controlled infusion (TCI) for anaesthesia. Additionally, new applications of existing anaesthetic drugs are being investigated. This review describes the current situation of anaesthetic drug development and methods of administration, and what can be expected in the near future