Approaching Maximal Precision of Hong-Ou-Mandel Interferometry with Nonperfect Visibility.

In quantum mechanics, the precision achieved in parameter estimation using a quantum state as a probe is determined by the measurement strategy employed. The quantum limit of precision is bounded by a value set by the state and its dynamics. Theoretical results have revealed that in interference measurements with two possible outcomes, this limit can be reached under ideal conditions of perfect visibility and zero losses. However, in practice, these conditions cannot be achieved, so precision never reaches the quantum limit. But how do experimental setups approach precision limits under realistic circumstances? In this Letter, we provide a model for precision limits in two-photon Hong-Ou-Mandel interferometry using coincidence statistics for nonperfect visibility and temporally unresolved measurements. We show that the scaling of precision with visibility depends on the effective area in time-frequency phase space occupied by the state used as a probe, and we find that an optimal scaling exists. We demonstrate our results experimentally for different states in a setup where the visibility can be controlled and reaches up to 99.5%. In the optimal scenario, a ratio of 0.97 is observed between the experimental precision and the quantum limit, establishing a new benchmark in the field.

The effectiveness and safety of non-pharmacological intervention for pain management in Parkinson's disease: A systematic review.

Chronic pain is a non-motor symptom affecting from 60 to 80% of patients with Parkinson's disease (PD). PD patients can suffer from different types of pain, either specific or not specific of the disease, and depending on various pathophysiological mechanisms (nociceptive, nociplastic or neuropathic), which can be present at any stage of the disease. Non-pharmacological interventions (NPIs) are essential to complement routine care interventions in PD pain management. Moreover, in the literature, it has been shown that 42% of PD patients are already using complementary therapies. Hence, our aim was to investigate the effectiveness and safety of NPIs for pain management in PD. A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Eighteen published randomized control trials (RCTs) were included between 2004 and 2021 leading to a total of 976 PD patients. From them, we reported fifteen different NPIs classified in seven categories: physical exercises, balneotherapy, manual therapy, acupuncture, botanical preparation, body-psychological practice and multiprotection care. Our results have shown that NPIs for PD pain management had a low-to-moderate level of evidence showing mainly favourable results, even if some NPIs presented inconclusive results. Moreover, our review highlighted the clinical relevance of some specific NPIs in PD pain management: NPIs consisting of active physical activities, opposed to passive activities. The safety of NPIs was also confirmed since only few minor transient adverse events were reported. Nevertheless, even if some interesting results were found, the methodology of future studies needs to be more robust and to include comprehensive descriptions in order to offer reliable and sound recommendations to clinicians.

Laparoscopic Colposacropexy Mesh Excision Secondary to Severe Spondylodiscitis.

STUDY OBJECTIVE: To describe laparoscopic mesh excision for severe spondylodiscitis secondary to colposacropexy mesh infection and demonstrate its feasibility. DESIGN: Step-by-step description of the surgical procedure using an educational video. SETTING: Spondylodiscitis is an uncommon and severe complication after sacrocolpopexy [1], with only 34 cases published to date [2]. Symptoms usually appear weeks after surgery, the most common being back pain irradiating toward the lower extremities and fever [3,4]. Treatment consists of intravenous antibiotic therapy for a minimum of 6 weeks, and approximately 70% require a surgical treatment [2] including mesh removal and debridement of the necrotic material [5]. INTERVENTIONS: A 55-year-old woman received an intervention for colposacropexy 2 months before owing to severe hysterocele and cystocele and consulted for fever and intense lumbar pain. She was diagnosed as having L5 to S1 spondylodiscitis secondary to colposacropexy mesh infection. She received endovenous antibiotic treatment for 6 weeks and underwent a laparoscopic mesh excision to facilitate resolution of infection. Laparoscopic approach with a standard 4-port placement configuration was used, enabling the identification of the colposacropexy mesh. Surgical strategy initially consisted of dissection of the promontory, vesicovaginal, and pararectal spaces, having previously identified the main anatomic landmarks to preserve them. Suspension of the promontory peritoneum and the bladder to the abdominal wall enabled a better exposure of the surgical field, facilitating the dissection and excision of the mesh. Postoperative course was uneventful, and the patient was discharged 4 days later. CONCLUSION: Owing to minimal morbidity and good results, laparoscopic mesh excision should be considered an effective treatment for spondylodiscitis secondary to mesh infection.

Parylene-based flexible neural probes with PEDOT coated surface for brain stimulation and recording.

Implantable neural prosthetics devices offer a promising opportunity for the restoration of lost functions in patients affected by brain or spinal cord injury, by providing the brain with a non-muscular channel able to link machines to the nervous system. Nevertheless current neural microelectrodes suffer from high initial impedance and low charge-transfer capacity because of their small-feature geometry (Abidian et al., 2010; Cui and Zhou, 2007). In this work we have developed PEDOT-modified neural probes based on flexible substrate capable to answer to the three critical requirements for neuroprosthetic device: efficiency, lifetime and biocompatibility. We propose a simple procedure for the fabrication of neural electrodes fully made of Parylene-C, followed by an electropolymerization of the active area with the conductive polymer PEDOT that is shown to greatly enhance the electrical performances of the device. In addition, the biocompatibility and the very high SNR exhibited during signal recording make our device suitable for long-term implantation.

[Localized giant pseudo polyposis of the colon. Apropos of a case]. / Pseudo-polypose colique géante localisée. A propos d'un cas.

A giant pseudo-polyposis lesion was diagnosed clinically and radiologically as cancer of right side of colon. The etiopathology of this lesion can probably be explained by the hemorrhagic rectocolitis that developed three years after its excision.