Quantum multifractality as a probe of phase space in the Dicke model.

We study the multifractal behavior of coherent states projected in the energy eigenbasis of the spin-boson Dicke Hamiltonian, a paradigmatic model describing the collective interaction between a single bosonic mode and a set of two-level systems. By examining the linear approximation and parabolic correction to the mass exponents, we find ergodic and multifractal coherent states and show that they reflect details of the structure of the classical phase space, including chaos, regularity, and features of localization. The analysis of multifractality stands as a sensitive tool to detect changes and structures in phase space, complementary to classical tools to investigate it. We also address the difficulties involved in the multifractal analyses of systems with unbounded Hilbert spaces.

On Thermal and Electrodynamic Aspects of the Superconductive Transition Process.

In a classic paper of 1960, W. H. Cherry and J. I. Gittleman discussed various thermal and electrodynamic aspects of the superconductive transition process relevant to practical applications. In a section of the paper that has remained unnoticed, they proposed a physical model for the Meissner effect. Earlier in 1940-1943, in work that has also remained unnoticed, K. M. Koch had introduced related physical ideas to explain the Meissner effect. Still earlier in 1937, J. C. Slater proposed a model to explain the perfect diamagnetism of superconductors. None of these ideas are part of the conventional London-BCS understanding of superconductivity, yet I will argue that they are essential to understand the Meissner effect, the most fundamental property of superconductors. The unconventional theory of hole superconductivity unifies and extends these ideas. A key missing element in the conventional theory as well as in these early theories is electron-hole asymmetry. A proper understanding of the Meissner effect may help with practical applications of superconductors, as well as to find new superconducting materials with desirable properties.

Quantification of inter-brain coupling: A review of current methods used in haemodynamic and electrophysiological hyperscanning studies.

Hyperscanning is a form of neuroimaging experiment where the brains of two or more participants are imaged simultaneously whilst they interact. Within the domain of social neuroscience, hyperscanning is increasingly used to measure inter-brain coupling (IBC) and explore how brain responses change in tandem during social interaction. In addition to cognitive research, some have suggested that quantification of the interplay between interacting participants can be used as a biomarker for a variety of cognitive mechanisms aswell as to investigate mental health and developmental conditions including schizophrenia, social anxiety and autism. However, many different methods have been used to quantify brain coupling and this can lead to questions about comparability across studies and reduce research reproducibility. Here, we review methods for quantifying IBC, and suggest some ways moving forward. Following the PRISMA guidelines, we reviewed 215 hyperscanning studies, across four different brain imaging modalities: functional near-infrared spectroscopy (fNIRS), functional magnetic resonance (fMRI), electroencephalography (EEG) and magnetoencephalography (MEG). Overall, the review identified a total of 27 different methods used to compute IBC. The most common hyperscanning modality is fNIRS, used by 119 studies, 89 of which adopted wavelet coherence. Based on the results of this literature survey, we first report summary statistics of the hyperscanning field, followed by a brief overview of each signal that is obtained from each neuroimaging modality used in hyperscanning. We then discuss the rationale, assumptions and suitability of each method to different modalities which can be used to investigate IBC. Finally, we discuss issues surrounding the interpretation of each method.

Chronic sacroiliac joint dysfunction and CT-guided percutaneous fixation: a 6-year experience.

PURPOSE: Reporting the clinical outcomes, patient satisfaction, and complications following an imaging-guided percutaneous screw fixation in the treatment of sacroiliac joint dysfunction and evaluating the safety and effectiveness of this method. METHODS: We performed a retrospective study on a prospectively gathered cohort of patients with physiotherapy-resistant pain due to sacroiliac joint incompetence that underwent percutaneous screw fixation, between 2016 and 2022 in our center. A minimum of two screws were used in all patients to obtain fixation of the sacroiliac joint, using percutaneous screw insertion under CT guidance, coupled with a C-arm fluoroscopy unit. RESULTS: The mean visual analog scale significantly improved at 6 months of follow-up (p < 0.05). One hundred percent of the patients reported significant improvement in pain scores at the final follow-up. None of our patients experienced intraoperative or postoperative complications. CONCLUSION: The use of percutaneous sacroiliac screws provides a safe and effective technique for the treatment of sacroiliac joint dysfunction in patients with chronic resistant pain.

Comment on "Carbon content drives high temperature superconductivity in a carbonaceous sulfur hydride below 100 GPa" by G. A. Smith, I. E. Collings, E. Snider, D. Smith, S. Petitgirard, J. S. Smith, M. White, E. Jones, P. Ellison, K. V. Lawler, R. P. Dias and A. Salamat, Chem. Commun., 2022, 58, 9064.

Experimental data supporting the claim that a carbonaceous sulfur hydride (CSH) under pressure is a high temperature superconductor were presented. Here we report results of a mathematical analysis that indicates that with probability larger than 1-10-338 some of those data were not measured in a laboratory, contrary to what the papers claim. This finding undermines confidence in the claim that any of the experimental evidence reported in those papers reflects the properties of real physical samples of CSH.

Correlation of Call Burden and Sleep Deprivation with Physician Burnout, Driving Crashes, and Medical Errors among US Neurointerventionalists.

BACKGROUND AND PURPOSE: High call frequency can lead to inadequate sleep, fatigue, and burnout, resulting in detrimental effects on physicians and patients. We aimed to assess the correlation between the frequency and burden of neurointerventional surgery calls and sleep deprivation with physician burnout, physical and driving safety, and fatigue-related medical errors. MATERIALS AND METHODS: We sent an online questionnaire to the members of the 2 neurointerventional surgery societies comprising 50 questions and spanning 3 main topics: 1) overnight/weekend call burden, 2) sleeping patterns, and 3) Copenhagen Burnout Inventory. RESULTS: One hundred sixty-four surveys were completed. Most (54%) neurointerventional surgeons reported burnout. Call burden of ≥1 every 3 days and being in practice >10 years were independent predictors of burnout. Thirty-nine percent reported falling asleep at the wheel, 23% reported a motor vehicle crash/near-crash, and 34% reported medical errors they considered related to call/work fatigue. On multivariate logistic regression, high call burden (called-in >3 times/week) was an independent predictor of sleeping at the wheel and motor vehicle crashes. Reporting <4 hours of uninterrupted sleep was an independent predictor of motor vehicle crashes and medical errors. Most neurointerventional surgeons recommended a maximum call frequency of once every 3 days. CONCLUSIONS: Call frequency and burden, number of years in practice, and sleep deprivation are associated with burnout of neurointerventional surgeons, sleeping at the wheel, motor vehicle crashes, and fatigue-related medical errors. These findings contribute to the increasing literature on physician burnout and may guide future societal recommendations related to call burden in neurointerventional surgery.

Minimally Invasive Stent Screw-Assisted Internal Fixation Technique Corrects Kyphosis in Osteoporotic Vertebral Fractures with Severe Collapse: A Pilot "Vertebra Plana" Series.

BACKGROUND AND PURPOSE: Fractures with "vertebra plana" morphology are characterized by severe vertebral body collapse and segmental kyphosis; there is no established treatment standard for these fractures. Vertebroplasty and balloon kyphoplasty might represent an undertreatment, but surgical stabilization is challenging in an often elderly osteoporotic population. This study assessed the feasibility, clinical outcome, and radiologic outcome of the stent screw-assisted internal fixation technique using a percutaneous implant of vertebral body stents and cement-augmented pedicle screws in patients with non-neoplastic vertebra plana fractures. MATERIALS AND METHODS: Thirty-seven consecutive patients with vertebra plana fractures were treated with the stent screw-assisted internal fixation technique. Vertebral body height, local and vertebral kyphotic angles, outcome scales (numeric rating scale and the Patient's Global Impression of Change), and complications were assessed. Imaging and clinical follow-up were obtained at 1 and 6 months postprocedure. RESULTS: Median vertebral body height restoration was 7 mm (+74%), 9 mm (+150%), and 3 mm (+17%) at the anterior wall, middle body, and posterior wall, respectively. Median local and vertebral kyphotic angles correction was 8° and 10° and was maintained through the 6-month follow-up. The median numeric rating scale score improved from 8/10 preprocedure to 3/10 at 1 and 6 months (P < .001). No procedural complications occurred. CONCLUSIONS: The stent screw-assisted internal fixation technique was effective in obtaining height restoration, kyphosis correction, and pain relief in patients with severe vertebral collapse.

Impact of myocardial injury after coronary artery bypass grafting on long-term prognosis.

AIMS: The most appropriate definition of perioperative myocardial infarction (pMI) after coronary artery bypass grafting (CABG) and its impact on clinically relevant long-term events is controversial. We aimed to (i) analyse the incidence of pMI depending on various current definitions in a 'real-life' setting of CABG surgery and (ii) determine the long-term prognosis of patients with pMI depending on current definitions. METHODS AND RESULTS: A consecutive cohort of 2829 coronary artery disease patients undergoing CABG from two tertiary university centres with the presence of serial perioperative cardiac biomarker measurements (cardiac troponin and creatine kinase-myocardial band) were retrospectively analysed. The incidence and prognostic impact of pMI were assessed according to (i) the 4th Universal Definition of Myocardial Infarction (4UD), (ii) the definition of the Society for Cardiovascular Angiography and Interventions (SCAI), and (iii) the Academic Research Consortium (ARC). The primary endpoint of this study was a composite of myocardial infarction, all-cause death, and repeat revascularization; secondary endpoints were mortality at 30 days and during 5-year follow-up. There was a significant difference in the occurrence of pMI (49.5% SCAI vs. 2.9% 4UD vs. 2.6% ARC). The 4th Universal Definition of Myocardial Infarction and ARC criteria remained strong independent predictors of all-cause mortality at 30 days [4UD: odds ratio (OR) 12.18; 95% confidence interval (CI) 5.00-29.67; P < 0.001; ARC: OR 13.16; 95% CI 5.41-32.00; P < 0.001] and 5 years [4UD: hazard ratio (HR) 2.13; 95% CI 1.19-3.81; P = 0.011; ARC: HR 2.23; 95% CI 1.21-4.09; P = 0.010]. Moreover, the occurrence of new perioperative electrocardiographic changes was prognostic of both primary and secondary endpoints. CONCLUSION: Incidence and prognosis of pMI differ markedly depending on the underlying definition of myocardial infarction for patients undergoing CABG. Isolated biomarker release-based definitions (such as troponin) were not associated with pMI relevant to prognosis. Additional signs of ischaemia detected by new electrocardiographic abnormalities, regional wall motion abnormalities, or coronary angiography should result in rapid action in everyday clinical practice.

Trends in opioid use following balloon kyphoplasty or vertebroplasty for the treatment of vertebral compression fractures.

This retrospective analysis of insurance claims evaluated real-world trends in prescription fills among patients treated with balloon kyphoplasty (N = 6,656) or vertebroplasty (N = 2,189) following diagnosis of vertebral compression fracture. Among those with evidence of opioid use, nearly half of patients discontinued or reduced prescription fills relative to pre-operative levels. INTRODUCTION: Vertebral compression fractures (VCF) are associated with debilitating pain, spinal misalignment, increased mortality, and increased healthcare-resource utilization in elderly patients. This study evaluated the effect of balloon kyphoplasty (BKP) or vertebroplasty (VP) on post-procedure opioid prescription fills and payer costs in patients with VCF. METHODS: This was a retrospective analysis of a large, nationally representative insurance-claims database. Clinical characteristics, opioid prescription patterns, and payer costs for subjects who underwent either BKP or VP to treat VCF were evaluated beginning 6 months prior to surgery through 7-month follow-up that included a 30-day, postoperative medication washout. Patient demographics, changes in opioid utilization, and payer costs were analyzed. RESULTS: A total of 8,845 patients met eligibility criteria (75.3% BKP and 24.7% VP) with a mean of age 77 and 74% female. Among the 75% of patients who used opioids, 48.7% of patients discontinued opioid medication and 8.4% reduced prescription fills versus preoperative baseline. Patients who reduced or discontinued prescriptions exhibited a decrease in all-cause payer costs relative to pre-intervention levels, which was a significantly greater change relative to patients with no change, increase, or new start of opioids. CONCLUSIONS: Interventional treatment for VCF was associated with decreased or discontinued opioid prescription fills and reduced payer costs in follow-up in a significant proportion of the study population. Reduction of opioid-based harms may represent a previously unrecognized benefit of vertebral augmentation for VCF, especially in this elderly and medically fragile population.

Quantum localization measures in phase space.

Measuring the degree of localization of quantum states in phase space is essential for the description of the dynamics and equilibration of quantum systems, but this topic is far from being understood. There is no unique way to measure localization, and individual measures can reflect different aspects of the same quantum state. Here we present a general scheme to define localization in measure spaces, which is based on what we call Rényi occupations, from which any measure of localization can be derived. We apply this scheme to the four-dimensional unbounded phase space of the interacting spin-boson Dicke model. In particular, we make a detailed comparison of two localization measures based on the Husimi function in the regime where the model is chaotic, namely, one that projects the Husimi function over the finite phase space of the spin and another that uses the Husimi function defined over classical energy shells. We elucidate the origin of their differences, showing that in unbounded spaces the definition of maximal delocalization requires a bounded reference subspace, with different selections leading to contextual answers.

Mycosis fungoides-derived exosomes promote cell motility and are enriched with microRNA-155 and microRNA-1246, and their plasma-cell-free expression may serve as a potential biomarker for disease burden.

BACKGROUND: Literature regarding exosomes as mediators in intercellular communication to promote progression in mycosis fungoides (MF) is lacking. OBJECTIVES: To characterize MF-derived exosomes and their involvement in the disease. METHODS: Exosomes were isolated by ultracentrifugation from cutaneous T-cell lymphoma (CTCL) cell lines, and from plasma of patients with MF and controls (healthy individuals). Exosomes were confirmed by electron microscopy, NanoSight and CD81 staining. Cell-line exosomes were profiled for microRNA array. Exosomal microRNA (exomiRNA) expression and uptake, and plasma-cell-free microRNA (cfmiRNA) were analysed by reverse-transcriptase quantitative polymerase chain reaction. Exosome uptake was monitored by fluorescent labelling and CD81 immunostaining. Migration was analysed by transwell migration assay. RESULTS: MyLa- and MJ-derived exosomes had a distinctive microRNA signature with abundant microRNA (miR)-155 and miR-1246. Both microRNAs were delivered into target cells, but only exomiR-155 was tested, demonstrating a migratory effect on target cells. Plasma levels of cfmiR-1246 were significantly highest in combined plaque/tumour MF, followed by patch MF, and were lowest in controls (plaque/tumour > patch > healthy), while cfmiR-155 was upregulated only in plaque/tumour MF vs. controls. Specifically, exomiR-1246 (and not exomiR-155) was higher in plasma of plaque/tumour MF than in healthy controls. Plasma exosomes from MF but not from controls increased cell migration. CONCLUSIONS: Our findings show that MF-derived exosomes promote cell motility and are enriched with miR-155, a well-known microRNA in MF, and miR-1246, not previously reported in MF. Based on their plasma expression we suggest that they may serve as potential biomarkers for tumour burden.

CTA Protocols in a Telestroke Network Improve Efficiency for Both Spoke and Hub Hospitals.

BACKGROUND AND PURPOSE: Telestroke networks support screening for patients with emergent large-vessel occlusions who are eligible for endovascular thrombectomy. Ideal triage processes within telestroke networks remain uncertain. We characterize the impact of implementing a routine spoke hospital CTA protocol in our integrated telestroke network on transfer and thrombectomy patterns. MATERIALS AND METHODS: A protocol-driven CTA process was introduced at 22 spoke hospitals in November 2017. We retrospectively identified prospectively collected patients who presented to a spoke hospital with National Institutes of Health Stroke Scale scores ≥6 between March 1, 2016 and March 1, 2017 (pre-CTA), and March 1, 2018 and March 1, 2019 (post-CTA). We describe the demographics, CTA utilization, spoke hospital retention rates, emergent large-vessel occlusion identification, and rates of endovascular thrombectomy. RESULTS: There were 167 patients pre-CTA and 207 post-CTA. The rate of CTA at spoke hospitals increased from 15% to 70% (P < .001). Despite increased endovascular thrombectomy screening in the extended window, the overall rates of transfer out of spoke hospitals remained similar (56% versus 54%; P = .83). There was a nonsignificant increase in transfers to our hub hospital for endovascular thrombectomy (26% versus 35%; P = .12), but patients transferred >4.5 hours from last known well increased nearly 5-fold (7% versus 34%; P < .001). The rate of endovascular thrombectomy performed on patients transferred for possible endovascular thrombectomy more than doubled (22% versus 47%; P = .011). CONCLUSIONS: Implementation of CTA at spoke hospitals in our telestroke network was feasible and improved the efficiency of stroke triage. Rates of patients retained at spoke hospitals remained stable despite higher numbers of patients screened. Emergent large-vessel occlusion confirmation at the spoke hospital lead to a more than 2-fold increase in thrombectomy rates among transferred patients at the hub.

Scavenging of Dickkopf-1 by macromer-based biomaterials covalently decorated with sulfated hyaluronan displays pro-osteogenic effects.

Dickkopf-1 (DKK1), a Wnt inhibitor secreted by bone marrow stromal cells (MSC), is known to play an important role in long-term non-union bone fracture defects and glucocorticoid induced osteoporosis. Mitigating its effects in early bone defects could improve osteogenesis and bone defect healing. Here, we applied a biomaterial strategy to deplete a defect environment from DKK1 by scavenging the protein via a macromer-based biomaterial covalently decorated with sulfated hyaluronan (sHA3). The material consisted of cross-copolymerized three-armed macromers with a small anchor molecule. Using the glycidyl anchor, polyetheramine (ED900) could be grafted to the material to which sHA3 was efficiently coupled in a separate step. For thorough investigation of material modification, flat material surfaces were generated by fabricating them on glass discs. The binding capability of sHA3 for DKK1 was demonstrated in this study by surface plasmon resonance measurements. Furthermore, the surfaces demonstrated the ability to scavenge and inactivate pathologic amounts of DKK1 from complex media. In a combinatory approach with Wnt3a, we were able to demonstrate that DKK1 is the preferred binding partner of our sHA3-functionalized surfaces. We validated our findings in a complex in vitro setting of differentiating SaOS-2 cells and primary hMSC. Here, endogenous DKK-1 was scavenged resulting in increased osteogenic differentiation indicating that this is a consistent biological effect irrespective of the model system used. Our study provides insights in the mechanisms and efficiency of sHA3 surface functionalization for DKK1 scavenging, which may be used in a clinical context in the future.