A realistic quantum many-body system, characterized by a generic microscopic Hamiltonian, is accessible only through approximation methods. The mean field theories, as the simplest practices of approximation methods, commonly serve as a powerful tool, but unfortunately often violate the symmetry of the Hamiltonian. The conventional BCS theory, as an excellent mean field approach, violates the particle number conservation and completely erases quantumness characterized by concurrence and quantum discord between different modes. We restore the symmetry by using the projected BCS theory and the exact numerical solution and find that the lost quantumness is synchronously reestablished. We show that while entanglement remains unchanged with the particle numbers, quantum discord behaves as an extensive quantity with respect to the system size. Surprisingly, discord is hardly dependent on the interaction strengths. The new feature of discord offers promising applications in modern quantum technologies.
Aberration correction is critical for obtaining sharp images but remains a challenging task. Owing to its ability to record both spatial and angular information of light rays, light field imaging is a powerful method to measure and correct optical aberrations. However, current methods need extensive calibrations to obtain prior information about the camera, which is restrictive in real-world applications.
High-harmonic generation (HHG) is a nonlinear process in which a material sample is irradiated by intense laser pulses, causing the emission of high harmonics of incident light. HHG has historically been explained by theories employing a classical electromagnetic field, successfully capturing its spectral and temporal characteristics. However, recent research indicates that quantum-optical effects naturally exist or can be artificially induced in HHG, such as entanglement between emitted harmonics.
Objective: Many review articles have explored data regarding the coexistence of specific types of pituitary adenomas (PAs) and polycystic ovary syndrome (PCOS), particularly focusing on the potential pathogenesis of this intersection and overlapping features. However, a comprehensive evaluation encompassing the full spectrum of PAs and their association with PCOS remains lacking. This review aims to provide a broad assessment of the interactions between these entities, emphasizing pathophysiological mechanisms, clinical presentations, diagnostic challenges and therapeutic implications.
Objective: To investigate retinal vascular permeability mapping as a potential biomarker for diabetic retinopathy in subjects with diabetes with no signs of retinopathy and with mild nonproliferative retinopathy.
Design: This is a case-control study.
Subjects: Participants included 7 healthy controls, 22 subjects with diabetes mellitus and no clinical signs of retinopathy (DMnoDR), and 7 subjects with mild nonproliferative diabetic retinopathy (NPDR).
Background: The possible nonlinear association with therapeutic outcomes in ulcerative colitis may contribute to the inconclusive cutoff values of fecal calprotectin (FC). We aimed to explore the nonlinear association between FC levels and long-term therapeutic outcomes in patients with ulcerative colitis and establish a clinically applicable FC index.
Methods: We included patients treated with vedolizumab or adalimumab from the VARSITY (n=661) and GEMINI 1 (n=620) studies as discovery and validation cohorts, respectively.
