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This paper examines the possibility of controlling the outcome of measured (flat space-time) relativistic effects, such as time dilation or length contractions, using pure rotations and their nontrivial interactions with Lorentz boosts in the isometry group SO + (3 , 1) . In particular, boost contributions may annihilate leaving only a geometric phase (Wigner rotation), which we see in the complex solutions of the generalized Euler decomposition problem in R 3 . We consider numerical examples involving specific matrix factorizations, along with possible applications in special relativity, electrodynamics and quantum scattering. For clearer interpretation and simplified calculations we use a convenient projective biquaternion parametrization which emphasizes the geometric phases and for a large class of problems allows for closed-form solutions in terms of only rational functions. [ABSTRACT FROM AUTHOR]

Background: Postoperative anal dilations (PAD) are the standard of care for patients after a posterior sagittal anorectoplasty (PSARP) for anorectal malformation (ARM) or a transanal pull-through (TP) procedure for Hirschsprung disease (HD). This study assessed the psychosocial impact of PAD among caregivers of children with ARM or HD, which may inform postoperative care strategies. Methods: Caregivers of patients with ARM and HD who underwent PSARP or TP within five years participated in the online survey. Questions included demographics, patient and caregiver experiences with PAD, and baseline psychosocial functioning. Quantitative results were reported descriptively, while qualitative responses were summarized as major themes. Results: The survey indicated a response rate of 26% caregivers, with most being female (91%) and biological mothers (85%). Patients were mostly male (65%), born with ARM (74%), and were five months old on average when PAD began. Caregivers reported that during PAD, children experienced distress (56%), pain (44%), and fear (41%), while a third noted no negative reactions. Over time, their child's ability to cope with PAD got easier (38%) or stayed the same (41%). Caregivers reported worry/anxiety (88%), guilt (71%), stress (62%), and frustration (35%), noting that additional coping strategies to manage the emotional and logistical challenges of daily PAD would be helpful. Conclusion: Although PAD is necessary, it can be highly stressful for the patients and their caregivers. Key findings emphasized the need for additional coping strategies and highlighted the importance of integrating psychosocial support into the postoperative care regimen. [ABSTRACT FROM AUTHOR]

The objective of this work is to derive the structure of Minkowski spacetime using a Hermitian spin basis. This Hermitian spin basis is analogous to the Pauli spin basis. The derived Minkowski metric is then employed to obtain the corresponding Lorentz factors, potential Lie algebra, effects on gamma matrices and complex representations of relativistic time dilation and length contraction. The main results, a discussion of the potential applications and future research directions are provided. [ABSTRACT FROM AUTHOR]

Background: VDD (atrial sensing, ventricular sensing/pacing) leads are relatively rarely implanted; therefore, experience in their extraction is very limited. We aimed to investigate whether VDD lead removal may be a risk factor for the increased complexity of transvenous lead extraction (TLE) or major complications. Methods: We retrospectively analyzed 3808 TLE procedures (including 103 patients with VDD leads). Results: If TLE included VDD lead removal, procedure duration (lead dilation time) was prolonged, complicated extractions were slightly more common, and more advanced tools were required. This is partly due to longer implant duration (in patients with VDD systems—135.2 months; systems without VDD leads—109.3 months; p < 0.001), more frequent presence of abandoned leads (all systems containing VDD leads—22.33% and all systems without VDD leads—10.77%), and partly to the younger age of patients with VDD leads (51.74 vs. 57.72 years; p < 0.001, in the remaining patients) at the time of system implantation. VDD lead extraction does not increase the risk of major complications (1.94 vs. 2.34%; p = 0.905). Conclusions: The extraction of VDD leads may be considered a risk factor for increased procedure complexity, but not for major complications. However, this is not a direct result of VDD lead extraction but specific characteristics of the patients with VDD leads. Operator skill and team experience combined with special custom maneuvers can enable favorable results to be achieved despite the specific design of VDD leads, even with older VDD lead models. [ABSTRACT FROM AUTHOR]