In this article, we attempt to summarize the 5-year long involvement of PSI through the CHART MagDev program with R&D on the Canted Cosine Theta (CCT) technology as a candidate for an FCC-hh main ...dipole magnet. We present the test results of the Canted Dipole 1 (CD1) 1-m-long 10-T Nb<inline-formula><tex-math notation="LaTeX">_{3}</tex-math></inline-formula>Sn demonstrator magnet, as well as a subjective list of 'pros and cons' of CCT for the FCC-hh that we compiled along the way. By sharing our conclusions, we hope to contribute to an ongoing discussion, while maintaining our utmost respect to the community of CCT developers. The presented findings and conclusions are not final, and we remain open to arguments and discussions, as well as technical exchanges on the topic.
In the context of high-energy physics, the use of Nb 3 Sn superconducting magnets as a cost-effective and reliable technology depends on improvements in the following areas: long development and ...manufacturing cycles, conductor degradation after thermal cycling, long training, as well as a demonstration in accelerator magnets with a beam aperture of the full potential of modern Nb 3 Sn conductors. In short, performance, robustness, and cost are the three issues to be addressed. The Magnet Development project (MagDev) of the Swiss Accelerator Research and Technology initiative (CHART) at the Paul Scherrer Institute (PSI) aims to contribute to the solutions to each of these issues, re-thinking the manufacturing and design process. In our program, every innovation is to be validated by means of a panoply of fast-turnaround tools: from non-powered and powered samples and coils, tested under background field, to low-field subscale magnets and high field short prototypes. This work presents one element in this panoply of R&D vehicles: a stress-managed Nb 3 Sn coil called BigBOX, impregnated with paraffin wax, and tested, through a collaboration with the Magnet Development Program of the United States (US-MDP), in the background field of Brookhaven National Laboratory (BNL)'s common coils dipole DCC17.
Training of accelerator magnets is a costly and time consuming process. The number of training quenches must therefore be reduced to a minimum. We investigate training of impregnated Nb 3 Sn ...Rutherford cable in a small-scale experiment named BOX (BOnding Experiment). The test involves a Rutherford cable impregnated in a meandering channel simulating the environment of a canted-cosine-theta (CCT) coil. The sample is powered using a transformer and the Lorentz force is generated by an externally applied magnetic field. The low material and helium consumption enable the test of a larger number of samples. In this article, we present training of samples impregnated with alumina-filled epoxy resins, a modified resin with paraffin-like mechanical properties, and a new tough resin in development at ETH Zürich. These new data are compared with previous results published earlier. Compared to samples with unfilled epoxy resin, those with alumina-filled epoxy show favorable training properties with higher initial quench currents and fewer training quenches before reaching 80% of the critical current.
Remifentanil is a highly potent opioid with a rapid onset and a short duration of action due to its rapid hydrolysis by esterases in blood and tissues. The major metabolite of remifentanil, GI90291, ...is much less potent than remifentanil.
The pharmacokinetics of remifentanil and its major metabolite, GI90291, were determined in 24 patients undergoing elective inpatient surgery. Remifentanil was administered as a 1-min infusion (2, 5, 15, and 30 micrograms/kg) after the induction of anesthesia and tracheal intubation. Serial arterial blood samples were collected over 6 h and assayed for remifentanil and GI90291.
The pharmacokinetics of remifentanil were described using a three-compartment model. Total clearance (250-300 l/h) of remifentanil was independent of dose and was approximately three to four times greater than the normal hepatic blood flow. Volume of distribution at steady state (25-40 l) also was independent of dose. The terminal half-life of remifentanil ranged from 10 to 21 min. Covariate analysis of remifentanil clearance and patient demographics showed that patient body weight, age, and gender did not influence total clearance. This suggests that remifentanil may not need to be dosed according to body weight in adult patients. A simulation was conducted to determine the time required for a 50% reduction in effect site concentration after an infusion designed to maintain a constant effect site concentration. The time required for a 50% reduction in the effect site concentration of remifentanil (3.65 min) was considerably less than that for sufentanil (33.9 min), alfentanil (58.5 min), and fentanyl (262 min). The pharmacokinetics of the major metabolite, GI90291, were independent of the dose of remifentanil. The mean terminal half-life of GI90291 ranged from 88 to 137 min.
The pharmacokinetics of remifentanil are consistent with its rapid elimination by blood and tissue esterases; its major metabolite is eliminated more slowly but is not likely to make any significant contribution to the total effect because of its much lower potency. The rapid onset and short duration of action of remifentanil make it well suited for titration of dose (infusion rate) to the desired degree of effect.
Seasonal trends in leaf gas exchange and ozone-induced visible foliar injury were investigated for three ozone sensitive woody plant species. Seedlings of
Populus nigra L.,
Viburnum lantana L., and
...Fraxinus excelsior L. were grown in charcoal-filtered chambers, non-filtered chambers and open plots. Injury assessments and leaf gas exchange measurements were conducted from June to October during 2002. All species developed typical ozone-induced foliar injury. For plants exposed to non-filtered air as compared to the charcoal-filtered air, mean net photosynthesis was reduced by 25%, 21%, and 18% and mean stomatal conductance was reduced by 25%, 16%, and 8% for
P. nigra,
V. lantana, and
F. excelsior, respectively. The timing and severity of the reductions in leaf gas exchange were species specific and corresponded to the onset of visible foliar injury.
Reductions in leaf gas exchange corresponded to the onset of ozone-induced visible foliar injury for seedlings exposed to ambient ozone exposures.
•Swiss healthcare professionals are generally opposed to vaccine mandates.•Swiss federal health authorities have clearly stated that vaccination is voluntary.•Swiss healthcare professionals expressed ...concerns about COVID-19 vaccine mandates.•Consequences of vaccine mandates for HCPs are currently unclear in Switzerland.•Vaccination policy in Switzerland should be clarified for healthcare professionals.
There currently are no mandatory vaccines in Switzerland. However, Swiss federal legislation allows for vaccination mandates in settings where the risk of transmission to vulnerable groups is high, such as healthcare professionals (HCPs) working with vulnerable patients. Since HCPs are trusted information sources, a priority population for COVID-19 vaccination, and potentially subjected to mandates, we investigated HCP perspectives on mandates.
A national online survey was administered to HCPs (October 2020-March 2021), including vaccine mandates questions concerning patients (measles) and HCPs (influenza). We qualitatively investigated HCP mandate perspectives through: (1) 34 interviews with HCPs, HCP professional society representatives, and health authorities; (2) a focus group discussion (FGD) with complementary medicine (CM) and biomedical physicians, and Swiss Federal Vaccination Commission members.
1933 participants (496 physicians, 226 pharmacists, 607 nurses, 604 midwives) responded to the survey. Quantitative results show all professional groups preferred shared parent-HCP measles vaccine decisions (65%, 54%, 50%, 48%, respectively; p for trend < 0.001). Midwives (87%) and nurses (70%) preferred individual influenza vaccination decisions for HCPs, while physicians (49%) and pharmacists (44%) preferred shared employee-employer decisions (p for trend < 0.001). Physicians (p < .001) and pharmacists (p < .01) with CM training favored individual influenza vaccination decisions. Qualitative results show general HCP opposition to vaccine mandates, mainly because participants argued how other approaches, such as HCP training and better information, could encourage uptake. Arguments against COVID-19 mandates included insufficiently documented long-term safety/efficacy data. From participants’ perspectives, mandated vaccination should be used as a last resort. Some participants expressed fear that with mandates, notably for influenza and COVID-19, some HCPs might leave their jobs. HCPs were unsure what vaccine mandates would concretely look like in practice, particularly regarding sanctions for non-compliance and enforcement.
In Switzerland, HCPs generally were opposed to vaccination mandates. Clarity and guidance are needed from health authorities to better inform discussions around vaccine mandates.
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