Tag: pubmed

Opt Lett. 2023 Jul 15;48(14):3793-3796. doi: 10.1364/OL.488848.

ABSTRACT

We demonstrate an extended Kalman filtering-enhanced linewidth measurement in short-delay self-heterodyne interferometry (SDSHI). We found that a modified SDSHI trace closely resembles a biased cosine wave, which would enable convenient linewidth estimation by its uniform envelope contrast without any correction factor. Experimentally, we adopted this approach for kHz laser linewidth measurement, taking advantages of extended Kalman filtering (EKF) to adaptively track the cosine wave. Apart from the measurement noise suppression, this approach could use as many data points as possible in the noisy trace to make a linewidth estimation at each tracked data point, from which we can deduce valuable statistical parameters such as the mean and standard deviation. This approach involves no more equipment than conventional SDSHI and sophisticated EKF so that it can be easily implemented. Therefore, we believe it will find wide applications in ultra-narrow laser linewidth measurement.

PMID:37450752 | DOI:10.1364/OL.488848

Opt Lett. 2023 Jul 15;48(14):3741-3744. doi: 10.1364/OL.493731.

ABSTRACT

We demonstrate an all-optical random number generator based on spontaneous symmetry breaking in a coherently driven Kerr resonator. Random bit sequences are generated by repeatedly tuning a control parameter across a symmetry-breaking bifurcation that enacts random selection between two possible steady-states of the system. Experiments are performed in a fiber ring resonator, where the two symmetry-broken steady-states are associated with orthogonal polarization modes. Detrimental biases due to system asymmetries are suppressed by leveraging a recently discovered self-symmetrization phenomenon that ensures the symmetry-breaking dynamics act as an unbiased coin toss, with a genuinely random selection between the two available steady-states. We optically generate bits at a rate of 3 MHz without post-processing and verify their randomness using the National Institute of Standards and Technology and Dieharder statistical test suites.

PMID:37450739 | DOI:10.1364/OL.493731

Opt Lett. 2023 Jul 15;48(14):3677-3680. doi: 10.1364/OL.494543.

ABSTRACT

Spatial beam self-cleaning, a manifestation of the Kerr effect in graded-index multimode fibers, involves a nonlinear transfer of power among modes, which leads to robust bell-shaped output beams. The resulting mode power distribution can be described by statistical mechanics arguments. Although the spatial coherence of the output beam was experimentally demonstrated, there is no direct study of modal phase evolutions. Based on a holographic mode decomposition method, we reveal that nonlinear spatial phase-locking occurs between the fundamental and its neighboring low-order modes, in agreement with theoretical predictions. As such, our results dispel the current belief that the spatial beam self-cleaning effect is the mere result of a wave thermalization process.

PMID:37450723 | DOI:10.1364/OL.494543

Opt Lett. 2023 Jul 15;48(14):3645-3648. doi: 10.1364/OL.494609.

ABSTRACT

In this Letter, we present a simple and versatile scheme for enhancing the nonclassical properties of light states using only linear optics and photodetectors. By combining a coherent state |α〉 and an arbitrary pure state of light |ϕ〉 (excluding coherent states) at two beam splitters, we show that the amplitude α of the coherent state can be tuned to filter out specific Fock components and generate states of light with increased nonclassical features. We provide two examples of input states and demonstrate the effectiveness of our scheme in enhancing the sub-Poissonian statistics or the quadrature squeezing of the output states.

PMID:37450715 | DOI:10.1364/OL.494609

Ann Surg. 2023 Jul 14. doi: 10.1097/SLA.0000000000006006. Online ahead of print.

ABSTRACT

OBJECTIVE: To develop and update evidence- and consensus-based guidelines on laparoscopic and robotic pancreatic surgery.

SUMMARY BACKGROUND DATA: Minimally invasive pancreatic surgery (MIPS), including laparoscopic and robotic surgery, is complex and technically demanding. Minimizing the risk for patients requires stringent, evidence-based guidelines. Since the International Miami Guidelines on MIPS in 2019, new developments and key publications have been reported, necessitating an update.

METHODS: Evidence-based guidelines on 22 topics in 8 domains were proposed: terminology, indications, patients, procedures, surgical techniques and instrumentation, assessment tools, implementation and training, and artificial intelligence. The Brescia Internationally Validated European Guidelines on Minimally Invasive Pancreatic Surgery (EGUMIPS, September 2022) used the Scottish Intercollegiate Guidelines Network (SIGN) methodology to assess the evidence and develop guideline recommendations, the Delphi method to establish consensus on the recommendations among the Expert Committee, the AGREE II-GRS tool for methodological guideline quality assessment, and external validation by a Validation Committee.

RESULTS: Overall, 27 European experts, 6 international experts, 22 international Validation Committee members, 11 Jury Committee members, 18 Research Committee members, and 121 registered attendees of the two-day meeting were involved in the development and validation of the guidelines. In total, 98 recommendations were developed, including 33 on laparoscopic, 34 on robotic and 31 on general MIPS covering 22 topics in 8 domains. Out of 98 recommendations, 97 reached at least 80% consensus among the experts and congress attendees, and all recommendations were externally validated by the Validation Committee.

CONCLUSIONS: The EGUMIPS evidence-based guidelines on laparoscopic and robotic MIPS can be applied in current clinical practice to provide guidance to patients, surgeons, policy-makers and medical societies.

PMID:37450702 | DOI:10.1097/SLA.0000000000006006

Ann Surg. 2023 Jul 17. doi: 10.1097/SLA.0000000000005948. Online ahead of print.

ABSTRACT

OBJECTIVES: To report the results of a rigorous quality control (QC) process in the grading of total mesorectal excision (TME) specimens during a multicenter prospective phase II trial of transanal TME.

SUMMARY BACKGROUND DATA: Grading of TME specimens is based on macroscopic assessment of the mesorectum and standardized through synoptic pathology reporting. TME grade is a strong predictor of outcomes with incomplete (IC) TME associated with increased rates of local recurrence relative to complete or near complete (C/NC) TME. Although TME grade serves as an endpoint in most rectal cancer trials, in protocols incorporating centralized review of TME specimens for quality assurance, discordance in grading and the management thereof has not been previously described.

METHODS: A phase II prospective taTME trial was conducted from 2017-2022 across 11 North American centers with TME quality as primary study endpoint. QC measures included training of site pathologists in TME protocols, (2) blinded grading of de-identified TME specimen photographs by central pathologists, and (3) reconciliation of major discordance prior to trial reporting. Cohen’s Kappa statistic was used to assess agreement in grading.

RESULTS: Overall agreement in grading of 100 TME specimens between site and central reviewer was rated as fair, (κ=0.35 (95% CI, 0.10-0.61, P<0.0001). Concordance was noted in 54%, with minor and major discordance in 32% and 14% of cases respectively. Upon reconciliation, 13/14 (93%) major discordances were resolved. Pre- versus post-reconciliation rates of C/NC and IC TME are 77%/16% and 7% versus 69%/21% and 10%. Reconciliation resulted in a major upgrade (IC to NC, N=1) or major downgrade (NC/C to IC, N=4) in 5 cases overall (5%).

CONCLUSIONS: A 14% rate of major discordance was observed in TME grading between site and central reviewers. Resolution resulted in a major change in final TME grade in 5% of cases, which suggests that reported rates or TME completeness are likely overestimated in trials. QC through central review of TME photographs and reconciliation of major discordances is strongly recommended.

PMID:37450694 | DOI:10.1097/SLA.0000000000005948

Compend Contin Educ Dent. 2023 Jul-Aug;44(7):392-401.

ABSTRACT

An intact extraction socket has been considered a prerequisite for an immediate implant placement and provisionalization (IIPP) procedure. Recent studies, however, have shown successful outcomes when IIPP was performed in sockets with a facial bone wall defect. This retrospective study evaluated the facial implant mucosal stability following IIPP in extraction sockets with a facial bone wall defect in the esthetic zone. The study included 16 cases in 16 patients who received maxillary anterior single IIPP with contour bone graft (C-BG) and contour connective tissue graft (C-CTG) in compromised extraction sockets (V- or U-shaped defect). After a mean follow-up of 6 years, the implant success rate was 100% (16/16). Minimal and non-statistically significant changes were noted in the facial implant mucosal and marginal bone level. Statistically significant changes were observed in facial implant mucosal thickness gain (2.5 mm [1.8 mm to 3.5 mm]) and midfacial bone sounding reduction (6 mm). Within the confines of this study, IIPP with simultaneous C-BG and C-CTG in fresh extraction sockets exhibiting a V- or U-shaped facial bone wall defect can lead to long-term successful outcomes in terms of mucosal stability, contour bone gain, and marginal bone level stability.

PMID:37450677

Urogynecology (Phila). 2023 Jul 13. doi: 10.1097/SPV.0000000000001397. Online ahead of print.

ABSTRACT

IMPORTANCE: Pudendal nerve block has been frequently used as a pain management modality for vaginal prolapse surgery. However, studies investigating its efficacy and the type of anesthetic used have had conflicting results.

OBJECTIVE: This study aimed to evaluate the effect of intraoperative pudendal nerve block with liposomal bupivacaine on postoperative pain after sacrospinous ligament suspension surgery.

STUDY DESIGN: In this single-blinded randomized controlled trial, 83 women undergoing sacrospinous ligament suspension were randomized to receive either intraoperative pudendal nerve block with liposomal bupivacaine or no block. Participants recorded their pain level on postoperative days (PODs) 1-3 and 7, the number of pain medication pills consumed, and the quality of their recovery using a validated questionnaire.

RESULTS: There were no significant differences in pain scores between the groups on POD 1 and POD 3: 5 (2-6.25) versus 5.5 (4-8; P = 0.058) and 4 (1-6) versus 5 (2-7; P = 0.146), respectively. On POD 2, the overall pain score was statistically different between the groups, with the block group having lower interquartile ranges. This difference, however, was not clinically significant: 5 (1.75-5) versus 5 (3.25-7.75; P = 0.023). In the subset of participants who underwent a concomitant midurethral sling procedure, POD 2 and POD3 pain scores were significantly lower in those who received the block: 3 (1-5) versus 6 (5-8; P = 0.006) for POD 2 and 3 (1-5) versus 5 (3.250-7; P = 0.042) for POD 3. There were no significant differences in pain medication consumption or the quality of recovery scores.

CONCLUSION: Pudendal nerve block with liposomal bupivacaine did not result in significant differences in postoperative pain after sacrospinous ligament suspension, except in those participants who underwent a concomitant midurethral sling procedure.

PMID:37450670 | DOI:10.1097/SPV.0000000000001397

Liver Transpl. 2023 Jul 17. doi: 10.1097/LVT.0000000000000219. Online ahead of print.

ABSTRACT

BACKGROUND: In Italy, 20 minutes of continuous, flat-line electrocardiogram are required for death declaration, which significantly increase the risks of DCD LT. Despite prolonged warm ischemia time, Italian centers reported good outcomes in controlled DCD (cDCD) LT by combining normothermic regional and end-ischemic machine perfusion. However, data on uncontrolled DCD (uDCD) LT performed by this approach are lacking.

PATIENTS AND METHODS: This was a multicenter, retrospective study performed at three large volume centers comparing clinical outcomes of uncontrolled versus controlled DCD LT. The aim of the study was to assess outcomes of sequential normothermic regional perfusion (NRP) and end-ischemic machine perfusion in uncontrolled DCD liver transplantation (LT) Results: Of 153 DCD donors evaluated during study period, 40 uDCD and 59 cDCD grafts were transplanted (utilization rate 52% vs. 78%, p = 0.004). Recipients of uDCD grafts had higher MEAF (4.9 vs. 3.5, p < 0.001) and CCI score at discharge (24.4 vs. 8.7, p = 0.026), longer ICU stay (5 vs. 4 d, p = 0.047) and a trend towards more severe AKI. At multivariate analysis, 90-days graft loss was associated with recipient BMI and lactate downtrend during NRP. One-year graft survival was lower in uDCD (75% vs. 90%, p = 0.007) but became comparable when non-liver-related graft losses were treated as censors (77% vs. 90%, p = 0.100). Incidence of ischemic cholangiopathy was 10% in uDCD versus 3% in cDCD, p = 0.356.

CONCLUSIONS: uDCD LT with prolonged warm ischemia is feasible by the sequential use of NRP and end-ischemic machine perfusion. Proper donor and recipient selection are key in achieving good outcomes in this setting.

PMID:37450659 | DOI:10.1097/LVT.0000000000000219

Hum Vaccin Immunother. 2023 Aug 1;19(2):2235963. doi: 10.1080/21645515.2023.2235963.

ABSTRACT

The intranasal spray COVID-19 vaccine was made available for the first time in China, it is necessary to understand receivers’ satisfaction and experience toward the vaccine to help optimize vaccination service. A self-administered multicenter cross-sectional questionnaire survey was conducted in Beijing, China, in December 2022. The vaccination experience was evaluated through three dimensions: immediate tolerance, smooth progress, and time-saving. Vaccine acceptability was measured by receivers’ preference for the intranasal spray over intramuscular injection after vaccination and their recommendation willingness. Stepwise multinomial and binary logistic regression models were applied to investigate factors associated with vaccine acceptability. Among 10,452 participants included in the analysis, 92.6% felt no discomfort during the inoculation, 99.8% thought the vaccination process went well, and 89.4% deemed it a time-saving option. For vaccine acceptability, 5566 (53.3%) participants were willing to recommend the vaccine to others, 534 (5.1%) refused, and 4352 (41.6%) had not decided yet; 6142 (58.8%) participants preferred the intranasal spray, 873 (8.4%) preferred the intramuscular injection, and 3437 (32.9%) had no preferences. The most concerned aspects of the intranasal spray vaccine were vaccine effectiveness and safety. Receivers who perceived higher vaccine effectiveness or safety were more likely to recommend it to others (OR, 95%CI: 4.41, 3.24-6.00; 6.11, 4.52-8.27) or prefer it over intramuscular injection after vaccination (OR, 95%CI: 5.94, 4.62-7.65; 8.50, 6.70-10.78). Receivers showed good acceptability and experience toward the intranasal spray COVID-19 vaccine. Vaccine effectiveness and safety were the most concerned aspects, and corresponding publicity and education efforts may help improve vaccine acceptability.

PMID:37450312 | DOI:10.1080/21645515.2023.2235963