Electrostatic potential in a superconductor

The electrostatic potential in a superconductor is studied. To this end Bardeen's extension of the Ginzburg-Landau theory to low temperatures is used to derive three Ginzburg-Landau equations - the Maxwell equation for the vector potential, the Schroedinger equation for the wave function and the Poisson equation for the electrostatic potential. The electrostatic and the thermodynamic potential compensate each other to a great extent resulting into an effective potential acting on the superconducting condensate. For the Abrikosov vortex lattice in Niobium, numerical solutions are presented and the different contributions to the electrostatic potential and the related charge distribution are discussed.Comment: 19 pages, 11 figure

Family physicians’ questions about the COVID-19 pandemic: a content analysis of 2,272 helpline calls

Abstract Background During the COVID-19 pandemic, family physicians faced challenges including travel restrictions for patients, lockdowns, diagnostic testing delays, and changing public health guidelines. Given that 95% of Canadian physicians are members of the Canadian Medical Protective Association (CMPA), the CMPA’s telephone helpline — which offers peer-to-peer support — provides valuable insights into family physicians’ experiences during the pandemic. Methods We used a content analysis approach to identify and understand family physicians’ questions and concerns related to the COVID-19 pandemic expressed during calls to the Canadian Medical Protective Association (CMPA) telephone helpline. Calls were classified with preliminary codes and subsequently organized into themes. We collected aggregated data on calls, including province, call date, and whether the physician self-identified having hospital-based activities as part of their practice. Findings from the analysis were explored alongside family physician calls per month (call volume). Results Between 01 and 2020 and 31 December 2021, 2,272 family physician calls related to the pandemic were included for content analysis. We identified six major themes across these calls: challenging patient interactions; COVID-related care; the impact of the pandemic on the healthcare system; virtual care; physician obligations and rights; and public health matters. COVID-related call volumes were highest early in the pandemic especially among physicians without major hospital affiliation when family physicians practiced with little guidance on how to balance patient care and scarce resources in the face of a novel pandemic. Conclusions This research provides unique insight on the effects the COVID-19 pandemic had on family medicine in Canada. These results provide insights on the needs and information gaps of family physicians in a public health crisis and can inform preparedness efforts by public health agencies, professional organizations, educators, and practitioners

Influence of solvents and detergents on matrix-assisted laser desorption/ionization mass spectrometry measurements of proteins and oligonucleotides.

The effect of solvents was found to be critical for sample preparation in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). For proteins and oligonucleotides the use of 2-propanol/water as a solvent for different matrices can significantly improve the quality of spectra. This effect is demonstrated with proteins ranging in molecular weight from 12 to 150 kDa and with a special 19-mer oligonucleotide. A comparison of MALDI-MS using of 2-propanol as matrix solvent and high-performance capillary electrophoresis resulted in identical relative peak intensities for a p(dT)12-18 oligonucleotide mixture. Additionally, the effect of detergents for characterization of high molecular weight proteins in very dilute solutions was studied with this solvent. It was found that Triton X-100, up to a concentration of 1%, was highly compatible with MALDI measurements and even could improve the quality of spectra. Use of detergents for cell profiling has extended the detectable mass range to about m/z 75,000

Additional file 2 of Family physicians’ questions about the COVID-19 pandemic: a content analysis of 2,272 helpline calls

Supplementary Material

Additional file 1 of Family physicians’ questions about the COVID-19 pandemic: a content analysis of 2,272 helpline calls

Supplementary Material