Exponential protection of zero modes in Majorana islands.

Majorana zero modes are quasiparticle excitations in condensed matter systems that have been proposed as building blocks of fault-tolerant quantum computers. They are expected to exhibit non-Abelian particle statistics, in contrast to the usual statistics of fermions and bosons, enabling quantum operations to be performed by braiding isolated modes around one another. Quantum braiding operations are topologically protected insofar as these modes are pinned near zero energy, with the departure from zero expected to be exponentially small as the modes become spatially separated. Following theoretical proposals, several experiments have identified signatures of Majorana modes in nanowires with proximity-induced superconductivity and atomic chains, with small amounts of mode splitting potentially explained by hybridization of Majorana modes. Here, we use Coulomb-blockade spectroscopy in an InAs nanowire segment with epitaxial aluminium, which forms a proximity-induced superconducting Coulomb island (a 'Majorana island') that is isolated from normal-metal leads by tunnel barriers, to measure the splitting of near-zero-energy Majorana modes. We observe exponential suppression of energy splitting with increasing wire length. For short devices of a few hundred nanometres, sub-gap state energies oscillate as the magnetic field is varied, as is expected for hybridized Majorana modes. Splitting decreases by a factor of about ten for each half a micrometre of increased wire length. For devices longer than about one micrometre, transport in strong magnetic fields occurs through a zero-energy state that is energetically isolated from a continuum, yielding uniformly spaced Coulomb-blockade conductance peaks, consistent with teleportation via Majorana modes. Our results help to explain the trivial-to-topological transition in finite systems and to quantify the scaling of topological protection with end-mode separation.

Association between glycaemic outcome and BMI in Danish children with type 1 diabetes in 2000-2018: a nationwide population-based study.

AIM: To describe the development of HbA1c and BMI over time in Danish children with type 1 diabetes; and to investigate the association between HbA1c and BMI including influence of age, gender, diabetes duration, severe hypoglycaemia and treatment method. METHODS: We used the nationwide Danish Registry of Childhood and Adolescent Diabetes, DanDiabKids, including annual registrations of all children with diabetes treated at Danish hospitals. With linear mixed-effects models and splines we analyzed the HbA1c and BMI development over time as well as the association between HbA1c and BMI including effects of gender, age, disease duration, hypoglycaemia and treatment method. BMI z-scores were calculated for these analyses. RESULTS: For the period from 2000 to 2018, 6097 children with type 1 diabetes were identified from the DanDiabKids database. The median (interquartile range) HbA1c level was 65 (57-74) mmol/mol (8.1%) and the median BMI z-score was 0.85 in girls and 0.67 in boys. A non-linear association was found between HbA1c and BMI z-score, with the highest BMI z-score observed for HbA1c values in the range of approximately 60-70 mmol/mol (7.6-6.8%). The association was modified by gender, age and diabetes duration. Severe hypoglycaemia and insulin pump treatment had a small positive impact on BMI z-score. CONCLUSION: The association between HbA1c and BMI z-score was non-linear, with the highest BMI z-score being observed for intermediate HbA1c levels; however, specific patterns depended on gender, age and diabetes duration.

Evening aspirin intake results in higher levels of platelet inhibition and a reduction in reticulated platelets - a window of opportunity for patients with cardiovascular disease?

Cardiovascular events occur most frequently in the early morning. Similarly, the release of reticulated platelets (RP) by megakaryocytes has a peak in the late night and early morning. Which aspirin regimen most effectively inhibits platelets during these critical hours is unknown. Hence, the primary objective of this trial was to assess platelet function and RP levels at 8.00 AM, in stable cardiovascular (CVD) patients, during three different aspirin regimens. In this open-label randomized cross-over study subjects were allocated to three sequential aspirin regimens: once-daily (OD) 80 mg morning; OD-evening, and twice-daily (BID) 40 mg. Platelet function was measured at 8.00 AM & 8.00 PM by serum Thromboxane B2 (sTxB2) levels, the Platelet Function Analyzer (PFA)-200® Closure Time (CT), Aspirin Reaction Units (ARU, VerifyNow®), and RP levels. In total, 22 patients were included. At 8.00 AM, sTxB2 levels were the lowest after OD-evening in comparison with OD-morning (p = <0.01), but not in comparison with BID. Furthermore, RP levels were similar at 8.00 AM, but statistically significantly reduced at 8.00 PM after OD-evening (p = .01) and BID (p = .02) in comparison with OD-morning. OD-evening aspirin intake results in higher levels of platelet inhibition during early morning hours and results in a reduction of RP levels in the evening. These findings may, if confirmed by larger studies, be relevant to large groups of patients taking aspirin to reduce cardiovascular risk.

Thyroid hormone treatment in the management of treatment-resistant unipolar depression: a systematic review and meta-analysis.

BACKGROUND: Treatment with thyroid hormones is occasionally used in the management of treatment-resistant depression. However, the evidence supporting this treatment is not fully established. The aim of this study was to systematically review the literature on the effect of adjunctive thyroid hormone in the management of treatment-resistant unipolar depression and to provide a pooled estimate of its efficacy. METHODS: The study is registered with PROSPERO (reg. no. CRD42018108088) and followed the PRISMA guidelines. Searches were carried out on June 24, 2019, in PubMed, EMBASE, and PsycINFO. Each record was screened independently by at least two reviewers. In instances of discrepancies, consensus was reached upon discussion. Pooled efficacy estimates were calculated based on response rates (decrease of ≥50% on the primary outcome measure) using random effect statistics. RESULTS: The search yielded 1355 records. Based on the screening of these records, we identified 10 studies that met the inclusion criteria (total number of patients = 663). The comparison of response to thyroid hormones vs. placebo resulted in an odds ratio of 1.56 (95% CI: 0.50-4.84). Similarly, the comparison of response to thyroid hormones vs. lithium resulted in an odds ratio of 1.91 (95% CI: 0.85-4.26). Thus, adjunctive therapy with thyroid hormones was not superior to placebo or lithium in the management of treatment-resistant unipolar depression. CONCLUSION: According to this review and meta-analysis, there is not sufficient evidence to support the use of adjunctive thyroid hormones for treatment-resistant unipolar depression.

Systems genetics analysis of pharmacogenomics variation during antidepressant treatment.

Selective serotonin reuptake inhibitors (SSRIs) are the most widely used antidepressants, but the efficacy of the treatment varies significantly among individuals. It is believed that complex genetic mechanisms play a part in this variation. We have used a network based approach to unravel the involved genetic components. Moreover, we investigated the potential difference in the genetic interaction networks underlying SSRI treatment response over time. We found four hub genes (ASCC3, PPARGC1B, SCHIP1 and TMTC2) with different connectivity in the initial SSRI treatment period (baseline to week 4) compared with the subsequent period (4-8 weeks after initiation), suggesting that different genetic networks are important at different times during SSRI treatment. The strongest interactions in the initial SSRI treatment period involved genes encoding transcriptional factors, and in the subsequent period genes involved in calcium homeostasis. In conclusion, we suggest a difference in genetic interaction networks between initial and subsequent SSRI response.

Prediction of bleeding and thrombosis by standard biochemical coagulation variables in haematological intensive care patients.

PURPOSE: We assessed the value of standard biochemical coagulation parameters in predicting bleeding, thrombosis and mortality in adult Intensive Care Unit (ICU) patients with haematological malignancies. METHODS: We screened all patients with acute leukaemia and myelodysplastic syndrome admitted to a university hospital ICU during 2008-2012. Data were obtained from the clinical chemistry laboratory database and patient files. We graded bleeding according to the World Health Organisation (WHO)-system within 24-h, within 5-days and during the whole ICU stay. We analysed the predictive values of laboratory parameters using multiple logistic regression and receiver operator characteristics (ROC) curves. As we previously have established that platelet count at admission was associated with bleeding, we focused on International Normalised Ratio (INR), activated pro-thrombin time (APTT), anti-thrombin, D-dimer and fibrinogen, and markers of infection (C-reactive protein, pro-calcitonin), kidney function (creatinine) and tissue damage (lactate dehydrogenase (LDH)). RESULTS: We included 116 patients; 66 (57%) had at least one bleeding episode and 11 (9%) patients had at least one thrombotic event. The differences in coagulation values when bleeding compared to baseline values were minor. INR was the only variable we found associated with subsequent bleeding within 24 h from admission to ICU (odds ratio 2.91, 95% CI: 1.01-8.43, P = 0.048). ROC analyses did not show predictive value of any of the other variables with regards to bleeding and none of the variables were associated with thrombosis in adjusted analyses. Increased levels of LDH at admission were associated with increased 7-day and 30-day mortality. CONCLUSIONS: Increased INR at admission was associated with a higher rate of bleeding in ICU patients with haematological malignancies. No other biochemical coagulation or other parameter had any association with bleeding, thrombosis or mortality except increased LDH, which at ICU admission was associated with increased 30-day mortality.

Diabetes and necrotizing soft tissue infections-A prospective observational cohort study: Statistical analysis plan.

BACKGROUND: Necrotizing soft tissue infections (NSTIs) are rare but carry a high morbidity and mortality. The multicenter INFECT project aims to improve the understanding of the pathogenesis, clinical characteristics, diagnosis, and prognosis of NSTIs. This article describes the study outline and statistical analyses that will be used. METHODS: Within the framework of INFECT project, patients with NSTI at 5 Scandinavian hospitals are enrolled in a prospective observational cohort study. The goal is to evaluate outcome and characteristics for patients with NSTI and diabetes compared to patients with NSTI without diabetes. The primary outcome is mortality at 90 days after inclusion. Secondary outcomes include days alive and out of ICU and hospital, SAPS II, SOFA score, infectious etiology, amputation, affected body area, and renal replacement therapy. Comparison in mortality between patients with diabetes type 1 and 2 as well as between insulin-treated and non-insulin-treated diabetes patients will be made. Clinical data for diabetic patients with NSTI will be reported. CONCLUSION: The study will provide important data on patients with NSTI and diabetes.

Necrotizing soft tissue infections - a multicentre, prospective observational study (INFECT): protocol and statistical analysis plan.

BACKGROUND: The INFECT project aims to advance our understanding of the pathophysiological mechanisms in necrotizing soft tissue infections (NSTIs). The INFECT observational study is part of the INFECT project with the aim of studying the clinical profile of patients with NSTIs and correlating these to patient-important outcomes. With this protocol and statistical analysis plan we describe the methods used to obtain data and the details of the planned analyses. METHODS: The INFECT study is a multicentre, prospective observational cohort study. Patients with NSTIs are enrolled in five Scandinavian hospitals, which are all referral centres for NSTIs. The primary outcomes are the descriptive variables of the patients. Secondary outcomes include identification of factors associated with 90-day mortality and amputation; associations between affected body part, maximum skin defect and Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score and 90-day mortality; 90-day mortality in patients with and without acute kidney injury (AKI) and LRINEC score of six and above or below six; and association between affected body part at arrival and microbiological findings. Exploratory outcomes include univariate analyses of baseline characteristics associations with 90-day mortality. The statistical analyses will be conducted in accordance with the predefined statistical analysis plan. CONCLUSION: Necrotizing soft tissue infections result in severe morbidity and mortality. The INFECT study will be the largest prospective study in patients with NSTIs to date and will provide important data for clinicians, researchers and policy makers on the characteristics and outcomes of these patients.

Volume of ropivacaine 0.2% and common peroneal nerve block duration: a randomised, double-blind cohort trial in healthy volunteers.

The volume-duration relationship using low concentrations of ropivacaine for peripheral nerve blocks is unknown, even though low concentrations of ropivacaine are increasingly used clinically. We investigated the effect of ropivacaine 0.2% on common peroneal nerve block duration. With ethical committee approval, 60 consenting, healthy volunteers were randomly allocated to receive one of five volumes of ropivacaine 0.2% (2.5, 5.0, 10, 15 or 20 ml) administered by ultrasound-guided, catheter-based injection (at 10 ml.min-1 ) near the common peroneal nerve. Our primary outcome was duration of sensory block, defined by insensitivity to a cold stimulus. Our secondary outcome was duration of motor block. Outcomes were assessed every hour from onset of block to complete remission. Intergroup differences were tested using one-way ANOVA followed by regression analyses using the 20 ml intervention group as reference. Block durations varied significantly (p < 0.0001) between groups. Mean (SD) sensory block durations were 9.2 (3.3), 12.5 (3.0), 15.5 (4.4), 17.3 (3.5) and 17.3 (4.6) h. Mean (SD) motor block durations were 3.3 (2.1), 7.2 (2.5), 9.2 (2.2), 12.7 (2.5) and 12.5 (2.5) h. Regression analysis showed that the effect of volume on block duration was progressively smaller with increasing volume, reaching a threshold volume above which there was no effect on nerve block duration (10 ml for sensory block and 15 ml for motor block). We conclude that there is a ceiling effect of increasing volume of ropivacaine 0.2% on both sensory and motor block duration of the common peroneal nerve.

Ischemic stroke subtype is associated with outcome in thrombolyzed patients.

OBJECTIVES: The impact of ischemic stroke subtype on clinical outcome in patients treated with intravenous tissue-type plasminogen activator (IV-tPA) is sparsely examined. We studied the association between stroke subtype and clinical outcome in magnetic resonance imaging (MRI)-evaluated patients treated with IV-tPA. MATERIAL AND METHODS: We conducted a single-center retrospective analysis of MRI-selected stroke patients treated with IV-tPA between 2004 and 2010. The Trial of ORG 10172 in Acute Stroke Treatment criteria were used to establish the stroke subtype by 3 months. The outcomes of interest were a 3-month modified Rankin Scale score of 0-1 (favorable outcome), and early neurological improvement defined as complete remission of neurological deficit or improvement of ≥4 on the National Institute of Health Stroke Scale at 24 h. The outcomes among stroke subtypes were compared with multivariable logistic regression. RESULTS: Among 557 patients, 202 (36%) had large vessel disease (LVD), 153 (27%) cardioembolic stroke (CE), 109 (20%) small vessel disease, and 93 (17%) were of other or undetermined etiology. Early neurological improvement was present in 313 (56.4%) patients, and 361 (64.8%) patients achieved a favorable outcome. Early neurological improvement and favorable outcome were more likely in CE patients compared with LVD patients (odds ratio (OR), 2.1 (95% confidence interval, 1.4-3.3), and 2.0 (95% confidence interval, 1.2-3.3), respectively). CONCLUSIONS: Cardioembolic stroke patients were more likely to achieve early neurological improvement and favorable outcome compared with LVD stroke following MRI-based IV-tPA treatment. This finding may reflect a difference in the effect of IV-tPA among stroke subtypes.

Influence of deep neuromuscular block on the surgeons assessment of surgical conditions during laparotomy: a randomized controlled double blinded trial with rocuronium and sugammadex.

BACKGROUND: During laparotomy, surgeons may experience difficult surgical conditions if the patient's abdominal wall or diaphragm is tense. Deep neuromuscular block (NMB), defined as a post-tetanic-count (PTC) between 0-1, paralyses the abdominal wall muscles and the diaphragm. We hypothesized that deep NMB (PTC 0-1) would improve subjective ratings of surgical conditions during upper laparotomy as compared with standard NMB. METHODS: This was a double blinded, randomized study. A total of 128 patients undergoing elective upper laparotomy were randomized to either continuous deep NMB (infusion of rocuronium 2 mg ml -1 ) or standard NMB (bolus of rocuronium 10 mg or increased depth of anaesthesia). Surgical conditions were evaluated using a 5-point subjective rating scale (1: extremely poor, 5: optimal) every 30 min. Primary outcome was the average of scores for a patient's surgical conditions. Other outcomes were surgical rating score during fascial closure, episodes of a need to optimize surgical conditions, occurrence of wound dehiscence, and wound infection. RESULTS: Deep compared with standard NMB resulted in better ratings of surgical conditions; median 4.75 (range 3-5) compared with 4.00 (range 1-5) ( P <0.001), respectively. Deep compared with standard NMB resulted in better ratings of surgical conditions during fascial closure ( P <0.001), fewer episodes of need to optimize surgical conditions ( P <0.001), and fewer incidents with sudden movements ( P <0.001). No differences in operating time, occurrence of wound infection, and wound dehiscence were found. CONCLUSIONS: Deep NMB compared with standard NMB resulted in better subjective ratings of surgical conditions during laparotomy. CLINICAL TRIAL REGISTRATION: NCT02140593.

Effects of red blood cell storage time on transfused patients in the ICU-protocol for a systematic review.

BACKGROUND: Patients in the intensive care unit (ICU) are often anaemic due to blood loss, impaired red blood cell (RBC) production and increased RBC destruction. In some studies, more than half of the patients were treated with RBC transfusion. During storage, the RBC and the storage medium undergo changes, which lead to impaired transportation and delivery of oxygen and may also promote an inflammatory response. Divergent results on the clinical consequences of storage have been reported in both observational studies and randomised trials. Therefore, we aim to gather and review the present evidence to assess the effects of shorter vs. longer storage time of transfused RBCs for ICU patients. METHODS: We will conduct a systematic review with meta-analyses and trial sequential analyses of randomised clinical trials, and also include results of severe adverse events from large observational studies. Participants will be adult patients admitted to an ICU and treated with shorter vs. longer stored RBC units. We will systematically search the Cochrane Library, MEDLINE, Embase, BIOSIS, CINAHL and Science Citation Index for relevant literature, and we will follow the recommendation by the Cochrane Collaboration and the Preferred Reporting Items for Systemtic Review and Meta-Analysis (PRISMA)-statement. We will assess the risk of bias and random errors, and we will use the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to evaluate the overall quality of evidence. CONCLUSION: We need a high-quality systematic review to summarise the clinical consequences of RBC storage time among ICU patients.

Validation of subjective rating scales for assessment of surgical workspace during laparoscopy.

BACKGROUND: Recently, studies have focused on how to optimize laparoscopic surgical workspace by changes in intra-abdominal pressure, level of muscle relaxation or body position, typically evaluated by surgeons using subjective rating scales. We aimed to validate two rating scales by having surgeons assess surgical workspace in video sequences recorded during laparoscopic surgery. METHOD: Video sequences were obtained from laparoscopic procedures. Eight experienced surgeons assessed the video sequences on a categorical 5-point scale and a numerical 10-point rating scale. Intraclass correlations coefficients (ICC) and 95% confidence intervals (CI) were calculated for intra- and inter-rater reliability. RESULTS: The 5-point rating scale had an intra-rater ICC of 0.76 (0.69; 0.83) and an inter-rater ICC of 0.57 (0.45; 0.68), corresponding to excellent and fair reliability, respectively. The 10-point scale had an intra-rater ICC of 0.86 (0.82; 0.89) and an inter-rater ICC of 0.54 (0.39; 0.68), corresponding to excellent and fair as well. All surgeons used the full range of the 5-point scale, but only one surgeon used the full range of the 10-point scale. CONCLUSION: In conclusion, both scales showed excellent intra-rater and fair inter-rater reliability for assessing surgical workspace in laparoscopy. The 5-point surgical rating scale had all categories employed by all surgeons.

Acute exercise and motor memory consolidation: Does exercise type play a role?

A single bout of high-intensity exercise can augment off-line gains in skills acquired during motor practice. It is currently unknown if the type of physical exercise influences the effect on motor skill consolidation. This study investigated the effect of three types of high-intensity exercise following visuomotor skill acquisition on the retention of motor memory in 40 young (25.3 ±3.6 years), able-bodied male participants randomly assigned to one of four groups either performing strength training (STR), circuit training (CT), indoor hockey (HOC) or rest (CON). Retention tests of the motor skill were performed 1 (R1h) and 24 h (R1d) post acquisition. For all exercise groups, mean motor performance scores decreased at R1h compared to post acquisition (POST) level; STR (P = 0.018), CT (P = 0.02), HOC (P = 0.014) and performance scores decreased for CT compared to CON (P = 0.049). Mean performance scores increased from POST to R1d for all exercise groups; STR (P = 0.010), CT (P = 0.020), HOC (P = 0.007) while performance scores for CON decreased (P = 0.043). Changes in motor performance were thus greater for STR (P = 0.006), CT (P < 0.001) and HOC (P < 0.001) compared to CON from POST to R1d. The results demonstrate that high-intensity, acute exercise can lead to a decrease in motor performance assessed shortly after motor skill practice (R1h), but enhances offline effects promoting long-term retention (R1d). Given that different exercise modalities produced similar positive off-line effects on motor memory, we conclude that exercise-induced effects beneficial to consolidation appear to depend primarily on the physiological stimulus rather than type of exercise and movements employed.

Initial placement and secondary displacement of a new suture-method catheter for sciatic nerve block in healthy volunteers: a randomised, double-blind pilot study.

We performed a randomised double-blind pilot study in 16 healthy volunteers to investigate the success rate for placing a new suture-method catheter for sciatic nerve block. A catheter was inserted into both legs of volunteers and each was randomly allocated to receive 15 ml lidocaine 2% through the catheter in one leg and 15 ml saline in the other leg. Successful placement of the catheter was defined as a 20% decrease in maximum voluntary isometric contraction for dorsiflexion of the ankle. Secondary outcomes were maximum voluntary isometric contraction for plantar flexion at the ankle, surface electromyography and cold sensation. After return of motor and sensory function, volunteers performed standardised physical exercises; injection of the same study medication was repeated in the same leg and followed by motor and sensory assessments. Fifteen of 16 (94%; 95%CI 72-99%) initial catheter placements were successful. The reduction in maximum voluntary isometric contraction and surface electromyography affected the peroneal nerve more often than the tibial nerve. Eleven of 15 (73%; 95%CI 54-96%) catheters remained functional with motor and sensory block after physical exercise, and the maximal displacement was 5 mm. Catheters with secondary block failure were displaced between 6 and 10 mm. One catheter was displaced 1.8 mm that resulted in a decrease in maximum voluntary isometric contraction of less than 20%. After repeat test injection, 14 of the 16 volunteers had loss of cold sensation. Neither motor nor sensory functions were affected in the legs injected with placebo. We conclude that the suture-method catheter can be placed with a high success rate, but that physical exercise may cause displacement.

Epitaxy of semiconductor-superconductor nanowires.

Controlling the properties of semiconductor/metal interfaces is a powerful method for designing functionality and improving the performance of electrical devices. Recently semiconductor/superconductor hybrids have appeared as an important example where the atomic scale uniformity of the interface plays a key role in determining the quality of the induced superconducting gap. Here we present epitaxial growth of semiconductor-metal core-shell nanowires by molecular beam epitaxy, a method that provides a conceptually new route to controlled electrical contacting of nanostructures and the design of devices for specialized applications such as topological and gate-controlled superconducting electronics. Our materials of choice, InAs/Al grown with epitaxially matched single-plane interfaces, and alternative semiconductor/metal combinations allowing epitaxial interface matching in nanowires are discussed. We formulate the grain growth kinetics of the metal phase in general terms of continuum parameters and bicrystal symmetries. The method realizes the ultimate limit of uniform interfaces and seems to solve the soft-gap problem in superconducting hybrid structures.

Effects of using the simplified airway risk index vs usual airway assessment on unanticipated difficult tracheal intubation - a cluster randomized trial with 64,273 participants.

BACKGROUND: Unanticipated difficult intubation remains a challenge in anaesthesia. The Simplified Airway Risk Index (SARI) is a multivariable risk model consisting of seven independent risk factors for difficult intubation. Our aim was to compare preoperative airway assessment based on the SARI with usual airway assessment. METHODS: From 01.10.2012 to 31.12.2013, 28 departments were cluster-randomized to apply the SARI model or usual airway assessment. The SARI group implemented the SARI model. The Non-SARI group continued usual airway assessment, thus reflecting a group of anaesthetists' heterogeneous individual airway assessments. Preoperative prediction of difficult intubation and actual intubation difficulties were registered in the Danish Anaesthesia Database for both groups. Patients who were preoperatively scheduled for intubation by advanced techniques (e.g. video laryngoscopy; flexible optic scope) were excluded from the primary analysis. Primary outcomes were the proportions of unanticipated difficult and unanticipated easy intubation. RESULTS: A total of 26 departments (15 SARI and 11 Non-SARI) and 64 273 participants were included. In the primary analyses 29 209 SARI and 30 305 Non-SARI participants were included.In SARI departments 2.4% (696) of the participants had an unanticipated difficult intubation vs 2.4% (723) in Non-SARI departments. Odds ratio (OR) adjusted for design variables was 1.03 (95% CI: 0.77-1.38). The proportion of unanticipated easy intubation was 1.42% (415) in SARI departments vs 1.00% (302) in Non-SARI departments. Adjusted OR was 1.26 (0.68-2.34). CONCLUSIONS: Using the SARI compared with usual airway assessment we detected no statistical significant changes in unanticipated difficult- or easy intubations. CLINICAL TRIAL REGISTRATION: NCT01718561.

Is deep neuromuscular blockade beneficial in laparoscopic surgery? Yes, probably.

BACKGROUND: Deep neuromuscular blockade during laparoscopic surgery may provide some clinical benefit. We present the 'Pro-' argument in this paired position paper. METHODS: We reviewed recent evidence from a basic database of references which we agreed on with the 'Con-' side, and present this in narrative form. We have shared our analysis and text with the authors of the 'Con-' side of these paired position papers during the preparation of the manuscripts. RESULTS: There are a few low risk of bias studies indicating that use of deep neuromuscular blockade improve surgical conditions and improve patient outcomes such as post-operative pain in laparoscopic surgery. CONCLUSION: Our interpretation of recent findings is that there is reason to believe that there may be some patient benefit of deep neuromuscular blockade in this context, and more detailed study is needed.

Collecting Validity Evidence for the Assessment of Mastery Learning in Simulation-Based Ultrasound Training.

PURPOSE: To collect validity evidence for the assessment of mastery learning on a virtual reality transabdominal ultrasound simulator. MATERIALS AND METHODS: We assessed the validity evidence using Messick's framework for validity. The study included 20 novices and 9 ultrasound experts who all completed 10 obstetric training modules on a transabdominal ultrasound simulator that provided automated measures of performance for each completed module (i. e., simulator metrics). Differences in the performance of the two groups were used to identify simulator metrics with validity evidence for the assessment of mastery learning. The novices continued to practice until they had attained mastery learning level. RESULTS: One-third of the simulator metrics discriminated between the two groups. The median simulator scores from a maximum of 40 metrics were 17.5 percent (range 0 - 45.0 percent) for novices and 90.0 percent (range 85.0 - 97.5) for experts, p < 0.001. Internal consistency was high, with a Cronbach's alpha value of 0.98. The test/retest reliability gave an intra-class correlation coefficient (ICC) of 0.62 for novices who reached the mastery learning level twice. Novices reached the mastery learning level within a median of 4 attempts (range 3 - 8) corresponding to a median of 252 minutes of simulator training (range 211 - 394 minutes). CONCLUSION: This study found that validity evidence for the assessment of mastery learning in simulation-based ultrasound training can be demonstrated and that ultrasound novices can attain mastery learning levels with less than 5 hours of training. Only one-third of the standard simulator metrics discriminated between different levels of competence.

Gigahertz Quantized Charge Pumping in Bottom-Gate-Defined InAs Nanowire Quantum Dots.

Semiconducting nanowires (NWs) are a versatile, highly tunable material platform at the heart of many new developments in nanoscale and quantum physics. Here, we demonstrate charge pumping, that is, the controlled transport of individual electrons through an InAs NW quantum dot (QD) device at frequencies up to 1.3 GHz. The QD is induced electrostatically in the NW by a series of local bottom gates in a state of the art device geometry. A periodic modulation of a single gate is enough to obtain a dc current proportional to the frequency of the modulation. The dc bias, the modulation amplitude and the gate voltages on the local gates can be used to control the number of charges conveyed per cycle. Charge pumping in InAs NWs is relevant not only in metrology as a current standard, but also opens up the opportunity to investigate a variety of exotic states of matter, for example, Majorana modes, by single electron spectroscopy and correlation experiments.