Implications of the Babinet Principle for Casimir Interactions

We formulate the Babinet Principle (BP) as a relation between the scattering amplitudes for electromagnetic waves, and combine it with multiple scattering techniques to derive new properties of Casimir forces. We show that the Casimir force exerted by a planar conductor or dielectric on a self- complementary perforated planar mirror is approximately half that on a uniform mirror independent of the distance between them. The BP suggests that Casimir edge effects are anomalously small, supporting results obtained earlier in special cases. Finally, we illustrate how the BP can be used to estimate Casimir forces between perforated planar mirrors

Lymphopenia and mortality among patients undergoing coronary angiography: Long-term follow-up study

Background: Lymphopenia is associated with adverse prognosis in chronic disease states that are related to immune dysregulation. We aimed to determine the association between lymphopenia and mortality in patients presenting to coronary angiography and investigate whether elevated red blood cell distribution width (RDW), an established cardiovascular prognostic marker, further refines risk stratification. Methods: Retrospective analysis of patients undergoing coronary angiography for evaluation or treatment of coronary artery disease between 2003 and 2018. Mortality risk associated with relative (1000–1500/μL) or severe (< 1000/μL) lymphopenia was analyzed using adjusted Cox proportional hazards regression models. Results: Overall, 15,179 patients aged 65 ± 12 years underwent coronary angiography. During a median follow-up of 8 years, 4253 patients died. Compared to normal lymphocyte count, the adjusted hazard ratio (HR) for mortality was 1.31 (95% confidence interval [CI] 1.21–1.41) and 1.97 (95% CI 1.75–2.22) for relative and severe lymphopenia, respectively. The increase in mortality associated with severe lymphopenia was significant in patients presenting in the non-acute setting (HR 2.18, 95% CI 1.74–2.73), ST-segment elevation myocardial infarction (STEMI) (HR 1.59, 95% CI 1.15–2.21), or unstable angina/non-STEMI (HR 2.00, 95% CI 1.70–2.34); p-value for interaction 0.626. The association of lymphopenia with mortality remained significant after additional adjustment to RDW. High RDW (> 14.5%) was associated with reduced survival, and it improved the predictive accuracy of lymphocytes count with an increase in Harrell’s Concordance statistic from 0.634 (SE = 0.005) to 0.672 (SE = 0.005), p < 0.001. Conclusions: lymphopenia is associated with increased risk of mortality during long-term follow-up in patients undergoing coronary angiography, regardless of the coronary presentation. High RDW may enhance the predictive ability of lymphopenia

Specific Recognition of p53 Tetramers by Peptides Derived from p53 Interacting Proteins

Oligomerization plays a major role in regulating the activity of many proteins, and in modulating their interactions. p53 is a homotetrameric transcription factor that has a pivotal role in tumor suppression. Its tetramerization domain is contained within its C-terminal domain, which is a site for numerous protein-protein interactions. Those can either depend on or regulate p53 oligomerization. Here we screened an array of peptides derived from proteins known to bind the tetrameric p53 C-terminal domain (p53CTD) and identified ten binding peptides. We quantitatively characterized their binding to p53CTD using fluorescence anisotropy. The peptides bound tetrameric p53CTD with micromolar affinities. Despite the high charge of the binding peptides, electrostatics contributed only mildly to the interactions. NMR studies indicated that the peptides bound p53CTD at defined sites. The most significant chemical shift deviations were observed for the peptides WS100B(81–92), which bound directly to the p53 tetramerization domain, and PKCα(281–295), which stabilized p53CTD in circular dichroism thermal denaturation studies. Using analytical ultracentrifugation, we found that several of the peptides bound preferentially to p53 tetramers. Our results indicate that the protein-protein interactions of p53 are dependent on the oligomerization state of p53. We conclude that peptides may be used to regulate the oligomerization of p53

Strategies for Facilitating Totally Percutaneous Transfemoral TAVR Procedures

Transcatheter aortic valve replacement (TAVR) has transformed the treatment of aortic stenosis and should ideally be performed as a totally percutaneous procedure via the transfemoral (TF) approach. Peripheral vascular disease may impede valve delivery, and vascular access site complications are associated with adverse clinical outcome and increased mortality. We review strategies aimed to facilitate TF valve delivery in patients with hostile vascular anatomy and achieve percutaneous management of vascular complications