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2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Yorgo Pano ◽  
Sabrina Pasterski ◽  
Andrea Puhm

Abstract Celestial diamonds encode the global conformal multiplets of the conformally soft sector, elucidating the role of soft theorems, symmetry generators and Goldstone modes. Upon adding supersymmetry they stack into a pyramid. Here we treat the soft charges associated to the fermionic layers that tie this structure together. This extends the analysis of conformally soft currents for photons and gravitons which have been shown to generate asymptotic symmetries in gauge theory and gravity to infinite-dimensional fermionic symmetries. We construct fermionic charge operators in 2D celestial CFT from a suitable inner product between 4D bulk field operators and spin s = $$ \frac{1}{2} $$ 1 2 and $$ \frac{3}{2} $$ 3 2 conformal primary wavefunctions with definite SL(2, ℂ) conformal dimension ∆ and spin J where |J| ≤ s. The generator for large supersymmetry transformations is identified as the conformally soft gravitino primary operator with ∆ = $$ \frac{1}{2} $$ 1 2 and its shadow with ∆ = $$ \frac{3}{2} $$ 3 2 which form the left and right corners of the celestial gravitino diamond. We continue this analysis to the subleading soft gravitino and soft photino which are captured by degenerate celestial diamonds. Despite the absence of a gauge symmetry in these cases, they give rise to conformally soft factorization theorems in celestial amplitudes and complete the celestial pyramid.


2021 ◽  
Vol 10 (22) ◽  
pp. 5350
Author(s):  
Maximilian Olschewski ◽  
Helen Ullrich ◽  
Moritz Brandt ◽  
Sebastian Steven ◽  
Majid Ahoopai ◽  
...  

Background—Several methods to reduce radiation exposure in the setting of coronary procedures are available on the market, and we previously showed that additional radiation shields reduce operator exposure during radial interventions. We set out to examine the efficacy of real-time personal dosimetry monitoring in a real-world setting of radial artery catheterization. Methods and Results—In an all-comer prospective, parallel study, consecutive coronary diagnostic and intervention procedures were performed with the use of standard radiation shield alone (control group) or with the addition of a real-time dosimetry monitoring system (Raysafe, Billdal, Sweden, monitoring group). The primary outcome was the difference in exposure of the primary operator among groups. Additional endpoints included patient, nurse, second operator exposure and fluoroscopy time. A total of 700 procedures were included in the analysis (n = 369 in the monitoring group). There were no differences among groups in patients’ body mass index (p = 0.232), type of procedure (intervention vs. diagnostic, p = 0.172), and patient sex (p = 0.784). Fluoroscopy time was shorter in the monitoring group (5.6 (5.1–6.2) min vs. 7.0 (6.1–7.7) min, p = 0.023). Radiation exposure was significantly lower in the monitoring group for the patient (135 (115–151) µSv vs. 208 (176–245) µSv, p < 0.0001) but not for the first operator (9 (7–11) µSv vs. 10 (8–11), p = 0.70) and the assistant (2 (1–2) µSv vs. 2 (1–2) µSv, p = 0.121). Conclusions—In clinical daily practice, the use of a real-time dosimetry monitoring device reduces patient radiation exposure and fluoroscopy time without an effect on operator radiation exposure.


2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Hidehiko Shimada ◽  
Hirohiko Shimada

Abstract We identify a nontrivial yet tractable quantum field theory model with space/time anisotropic scale invariance, for which one can exactly compute certain four-point correlation functions and their decompositions via the operator-product expansion(OPE). The model is the Calogero model, non-relativistic particles interacting with a pair potential $$ \frac{g}{{\left|x-y\right|}^2} $$ g x − y 2 in one dimension, considered as a quantum field theory in one space and one time dimension via the second quantisation. This model has the anisotropic scale symmetry with the anisotropy exponent z = 2. The symmetry is also enhanced to the Schrödinger symmetry. The model has one coupling constant g and thus provides an example of a fixed line in the renormalisation group flow of anisotropic theories.We exactly compute a nontrivial four-point function of the fundamental fields of the theory. We decompose the four-point function via OPE in two different ways, thereby explicitly verifying the associativity of OPE for the first time for an interacting quantum field theory with anisotropic scale invariance. From the decompositions, one can read off the OPE coefficients and the scaling dimensions of the operators appearing in the intermediate channels. One of the decompositions is given by a convergent series, and only one primary operator and its descendants appear in the OPE. The scaling dimension of the primary operator we computed depends on the coupling constant. The dimension correctly reproduces the value expected from the well-known spectrum of the Calogero model combined with the so-called state-operator map which is valid for theories with the Schrödinger symmetry. The other decomposition is given by an asymptotic series. The asymptotic series comes with exponentially small correction terms, which also have a natural interpretation in terms of OPE.


2021 ◽  
Vol 108 (Supplement_6) ◽  
Author(s):  
A Nessa ◽  
S Aspinall

Abstract Introduction Impact of trainee surgeons performing thyroid procedure on patient safety Aim The primary aim was to evaluate the impact of trainee as the principal operator on patient safety in thyroid surgery. Method The data was extracted from a single consultant’s data from 2009 to 2020 in the British Association of Endocrine and Thyroid Surgeons (BAETS) National audit. Multivariable analysis of predictive factors (including trainee primary operator) for temporary and permanent hypocalcaemia was performed. Results There were 507 thyroid cases. After excluding cases with missing data in variables analysed 378 (74.5%) cases were analysed. Vocal cord palsy occurred in 5/378 (1.3%), postoperative bleeding 3/378 (0.8%), temporary hypocalcaemia 68/378 (18.0%) and permanent hypocalcaemia 20/378 (5.3%). Predictive factors analysed included hyperthyroidism 117/378 (31%), retrosternal goitre 33/378 (8%), reoperation, 43/378 (11%), total thyroidectomy 184/378 (49%), nodal dissection 21/378 (6%) and trainee principal operator 15/378 (4%). Multivariable analyses of temporary and permanent hypocalcaemia found only two variables significantly affected incidence of temporary hypocalcaemia were total thyroidectomy (OR 7.82, 95% CI 3.41-17.92, p &lt; 0.001) and nodal dissection (OR 3.53, 95% CI 1.20-10.38, p = 0.02), and for permanent hypocalcaemia these were reoperation (OR 5.05, 95% CI 1.09-23.25, p = 0.04) and total thyroidectomy (OR 5.76, 95% CI 1.35-24.54, p = 0.018). Conclusions There was no evidence that trainee principal operator adversely affected the outcome of thyroidectomy; it is worth noting that only 4% of operations were done by trainees and so this study would support trainees undertaking more thyroidectomies as principal surgeon.


Author(s):  
Javier Ferrari Ayarragaray ◽  
Ricardo Speranza ◽  
Hector Mazzetti ◽  
Alejandro Girela ◽  
Claudio De Zuloaga ◽  
...  

Background and aim: RENEDI (“Registro Nacional de Extracción de Dispositivos”) is the first registry on Transvenous Lead Extraction (TLE) designed in Argentina with the objective of providing data on lead extraction real-world practice. Methods: An online database platform was designed. Data referred to patients, leads and extraction procedures were compiled and reviewed by a Committee. Results: A total of 621 leads were extracted from 325 patients (average age of 59 years; 71% male). The targeted leads included 374 pacemaker leads (61%), 176 implantable cardioverter-defibrillator leads (28%) and 71 cardiac resynchronization therapy devices (11%). Two hundred and thirty-three (38%) atrial, 367 (59%) ventricular and 21 (3%) coronary sinus leads placement. The average lead dwell time was 105. 9 months. The commonest indication for removal was infection (68%-Local 71%). Cardiovascular surgeons were usually the primary operator (81%). The presence of cardiovascular stand-by was reported in 72% of cases. Percutaneous approach (98%) was predominant. A total of 158 (25%) leads with a median dwell time of 33.3 months were extracted using simple traction. Overall complication rate was 4%. Only one major complication and no deaths were informed. Minor complications occurred in 3.6% of procedures. Complete procedural success was 96.2%. Incomplete extraction was obtained in 23 leads. No permanent disabling complications or procedure-related deaths were reported. Conclusions: Current Argentinian practice has demonstrated that TLE is a safe and effective procedure associated with a low incidence of complications and high success rate when it is performed in well-trained hands.


2021 ◽  
pp. neurintsurg-2021-017460
Author(s):  
Michael K Tso ◽  
Gary B Rajah ◽  
Rimal H Dossani ◽  
Michael J Meyer ◽  
Matthew J McPheeters ◽  
...  

BackgroundThe perception of a steep learning curve associated with transradial access has resulted in its limited adoption in neurointervention despite the demonstrated benefits, including decreased access-site complications.ObjectiveTo compare learning curves of transradial versus transfemoral diagnostic cerebral angiograms obtained by five neurovascular fellows as primary operator.MethodsThe first 100–150 consecutive transradial and transfemoral angiographic scans performed by each fellow between July 2017 and March 2020 were identified. Mean fluoroscopy time per artery injected (angiographic efficiency) was calculated as a marker of technical proficiency and compared for every 25 consecutive procedures performed (eg, 1–25, 26–50, 51–75).ResultsWe identified 1242 diagnostic angiograms, 607 transradial and 635 transfemoral. The radial cohort was older (64.3 years vs 62.3 years, p=0.01) and demonstrated better angiographic efficiency (3.4 min/vessel vs 3.7 min/vessel, p=0.03). For three fellows without previous endovascular experience, proficiency was obtained between 25 and 50 transfemoral angiograms. One fellow achieved proficiency after performing 25–50 transradial angiograms; and the two other fellows, in <25 transradial angiograms. The two fellows with previous experience had flattened learning curves for both access types. Two patients experienced transient neurologic symptoms postprocedure. Transradial angiograms were associated with significantly fewer access-site complications (3/607, 0.5% vs 22/635, 3.5%, p<0.01). Radial-to-femoral conversion occurred in 1.2% (7/607); femoral-to-radial conversion occurred in 0.3% (2/635). Over time, the proportion of transradial angiographic procedures increased.ConclusionTechnical proficiency improved significantly over time for both access types, typically requiring between 25 and 50 diagnostic angiograms to achieve asymptomatic improvement in efficiency. Reduced access-site complications and decreased fluoroscopy time were benefits associated with transradial angiography.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Dario Benedetti

Abstract We prove the instability of d-dimensional conformal field theories (CFTs) having in the operator-product expansion of two fundamental fields a primary operator of scaling dimension h = $$ \frac{d}{2} $$ d 2 + i r, with non-vanishing r ∈ ℝ. From an AdS/CFT point of view, this corresponds to a well-known tachyonic instability, associated to a violation of the Breitenlohner-Freedman bound in AdSd+1; we derive it here directly for generic d-dimensional CFTs that can be obtained as limits of multiscalar quantum field theories, by applying the harmonic analysis for the Euclidean conformal group to perturbations of the conformal solution in the two-particle irreducible (2PI) effective action. Some explicit examples are discussed, such as melonic tensor models and the biscalar fishnet model.


2021 ◽  
Vol 64 (3) ◽  
pp. E298-E306
Author(s):  
Michael T. Meschino ◽  
Andrew E. Giles ◽  
Paul T. Engels ◽  
Timothy J. Rice ◽  
Rahima Nenshi ◽  
...  

Background: The acute care surgery (ACS) model has been shown to improve patient, hospital and surgeon-specific outcomes. To date, however, little has been published on its impact on residency training. Our study compared the emergency general surgery (EGS) operative experiences of residents assigned to ACS versus elective surgical rotations. Methods: Resident-reported EGS case logs were prospectively collected over a 9-month period across 3 teaching hospitals. Descriptive statistics were tabulated and group comparisons were made using χ2 statistics for categorical data and t tests for continuous data. Results: Overall, 1061 cases were reported. Resident participation exceeded 90%). Appendiceal and biliary disease accounted for 49.7% of EGS cases. Residents on ACS rotations reported participating in twice as many EGS cases per block as residents on elective rotations (12.64 v. 6.30 cases, p < 0.01). Most cases occurred after hours while residents were on call rather than during daytime ACS hours (78.8% v. 21.1%, p < 0.01). Senior residents were more likely than junior residents to report having a primary operator role (71.3% v. 32.0%, p < 0.01). Although the timing of cases made no difference in the operative role of senior residents, junior residents assumed the primary operator role more often during the daytime than after hours (50.0% v. 33.1%, p = 0.01). Conclusion: Despite implementation of the ACS model, residents in our program obtained most of their EGS operative experience after hours while on call. Although further research is needed, our study suggests that improved daytime access to the operating room may represent an opportunity to improve the quantity and quality of the EGS operative experience at our academic network.


EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
M Hudec ◽  
J Chovancik ◽  
O Jiravsky ◽  
J Hecko ◽  
R Miklik ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background occlusion of the left atrial appendage (LAA) is an established method in the prevention of thromboembolic complications in patients with atrial fibrillation and high bleeding risk. There is a huge anatomical variability of LAA and choosing the right type and size of the occluder may be challenging and result in a time-consuming procedure with repeated repositioning of the selected device, or a need to use another device. These aspects may lead to a prolonged or more aggressive manipulation resulting in periprocedural complications and a suboptimal result. The current technology of 3D printing allows us to obtain a real model of the LAA and to simulate the course of implantation. Purpose in a post-hoc analysis to compare occluder sizes predicted as optimal by simulation on a 3D-printed LAA model to actually implanted LAA occluders, and analyse potential benefits of such simulations. Methods We analysed 32 consecutive patients after a TEE-guided implantation of the Amulet occluder in whom a CT cardiac scan had been performed prior to the procedure. Based on the CT, an LAA 3D model was printed out post-hoc for each patient. Two experienced operators blinded to the procedural results simulated the implantation ex-vivo and agreed on the most appropriate size of the occluder to fit in the LAA. If the simulation-based size matched the size of the primary operator`s choice and this occluder was actually implanted („intention-to-implant and implanted"), the match was considered positive; otherwise it was negative. The number of positive and negative matches and corresponding procedural characteristics were analysed. Results The positive match was found in 9 (28.1%) cases. Out of 23 (71.9%) negative matches, there were 11 (47.8%) implantations using a bigger-than-simulated and 12 (52.2%) smaller-than-simulated occluder; in 2 (8.7%) cases the actually implanted occluder matched the simulated size but was a 2nd -choice occluder. In positive-match cases compared to negative-match cases, there was a statistically significant less need for an occluder reposition (median 0.0 vs 1.0, p = 0,02), and a trend to a shorter procedural time (average 66.7+ 13.3 min vs 85.2 + 32.8 min, p = 0.112) and less contrast agent consumption (average 188.9 + 67.9ml vs 220.9 + 112.4ml, p = 0.43). Conclusion  The preliminary results of our study suggest that a CT-based 3D modelling of the LAA shape and simulating the LAA occlusion procedure ex-vivo have a potential to become useful tools to reduce procedural time and complications. Our results might serve as a rational for a prospective study. Abstract Figure. Occluder in the 3D model


2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
S Gysling ◽  
G Maresca ◽  
A Brooks ◽  
A Patel ◽  
E Caruana

Abstract Introduction Delivery of surgical services during the Covid-19 pandemic has required the use of enhanced PPE in the operating theatre. We sought to evaluate the impact of this change on surgeon workload and intraoperative patient outcomes. Method Surgeons performing as primary operator completed an online procedure-specific questionnaire on workload ratings for each operative case, using an extension of the validated Surgeon Task Load Index (SURG-TLX) tool (reported on a 20-point scale), together with operative details. Local approval was obtained at individual sites. Data was analysed in Stata SE v16. Results 118 responses (17 surgeons, 7 specialties) were collected from June to September 2020. 77.1% used enhanced PPE. There was no association between enhanced PPE use and overall workload (p = 0.151) as measured with SURG-TLX, although surgeons wearing enhanced PPE commonly reported finding individual procedures harder than expected (37% vs 0%, p &lt; 0.001). Communication was rated worse when using enhanced PPE use (MD -4.38, 95%CI -6.74 to 02.03; p &lt; 0.001). There was no association between enhanced PPE use and intraoperative complications (p = 0.745). Conclusions The use of enhanced PPE is not associated with complications or increased surgeon workload assessed by SURG-TLX. It is, however, associated with difficulty in communicating, and subjectively experiencing more procedural challenge than anticipated.


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