149 research outputs found
A generalization of the Entropy Power Inequality to Bosonic Quantum Systems
In most communication schemes information is transmitted via travelling modes
of electromagnetic radiation. These modes are unavoidably subject to
environmental noise along any physical transmission medium and the quality of
the communication channel strongly depends on the minimum noise achievable at
the output. For classical signals such noise can be rigorously quantified in
terms of the associated Shannon entropy and it is subject to a fundamental
lower bound called entropy power inequality. Electromagnetic fields are however
quantum mechanical systems and then, especially in low intensity signals, the
quantum nature of the information carrier cannot be neglected and many
important results derived within classical information theory require
non-trivial extensions to the quantum regime. Here we prove one possible
generalization of the Entropy Power Inequality to quantum bosonic systems. The
impact of this inequality in quantum information theory is potentially large
and some relevant implications are considered in this work
Large-scale multiconfiguration Hartree-Fock calculations of hyperfine-interaction constants for low-lying states in beryllium, boron, and carbon
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Is Sexual Function Impacted After Minimally Invasive Surgery for Benign Prostatic Obstruction?
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Are all procedures for benign prostatic hyperplasia created equal? A systematic review on post-procedural PSA dynamics and its correlation with relief of bladder outlet obstruction
Purpose To evaluate and provide a comprehensive literature review of Prostate specific antigen (PSA) dynamics after various surgical procedures for benign prostatic hyperplasia (BPH). Methods A thorough PubMed database search was performed over last 30 years including terms "PSA" and various surgical procedures for BPH. PSA nadir after various procedure was evaluated. The post-operative improvement in International Prostate Symptom Score, maximum void rates and post-void residue after surgeries were recorded. An indirect correlation was made between PSA nadir and outcome of various BPH surgical procedures. Results Enucleation procedures like simple prostatectomy and endoscopic enucleation of prostate (EEP) produced maximum drop in PSA level after surgery and were associated with the highest improvement in post-operative parameters. The PSA nadir following resection techniques like transurethral resection of prostate and Holmium laser resection of prostate and vaporization technique was variable and less robust when compared to EEP. Newer techniques like Aquablation, Rezum, Urolift, Prostate artery embolization and Temporary implantable nitinol devices (iTIND) produce relatively less reduction in PSA and lesser percentile improvement in post-operative parameters. Conclusions Various surgical procedures for BPH result in varying PSA nadirs level. Enucleation procedures and simple prostatectomy produce the most drastic and sustained decrease in PSA. There is a possible indirect evidence suggesting that the level of PSA nadir corresponds closely with the degree of post-operative improvement and durability of the procedure. Establishing the new PSA nadir at 3-6 months after the procedure is recommended as a part of routine surveillance for prostate cancer in eligible patients
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