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Spins of electrons in silicon MOS quantum dots combine exquisite quantum properties and scalable fabrication. In the age of quantum technology, however, the metrics that crowned Si/SiO 2 as the microelectronics standard need to be reassessed with respect to their impact upon qubit performance. We chart spin qubit variability due to the unavoidable atomic-scale roughness of the Si/SiO 2 interface, compiling experiments across 12 devices, and develop theoretical tools to analyse these results. Atomistic tight binding and path integral Monte Carlo methods are adapted to describe fluctuations in devices with millions of atoms by directly analysing their wavefunctions and electron paths instead of their energy spectra. We correlate the effect of roughness with the variability in qubit position, deformation, valley splitting, valley phase, spin-orbit coupling and exchange coupling. These variabilities are found to be bounded, and they lie within the tolerances for scalable architectures for quantum computing as long as robust control methods are incorporated., (© 2024. The Author(s).)

The encoding of qubits in semiconductor spin carriers has been recognized as a promising approach to a commercial quantum computer that can be lithographically produced and integrated at scale 1-10 . However, the operation of the large number of qubits required for advantageous quantum applications 11-13 will produce a thermal load exceeding the available cooling power of cryostats at millikelvin temperatures. As the scale-up accelerates, it becomes imperative to establish fault-tolerant operation above 1 K, at which the cooling power is orders of magnitude higher 14-18 . Here we tune up and operate spin qubits in silicon above 1 K, with fidelities in the range required for fault-tolerant operations at these temperatures 19-21 . We design an algorithmic initialization protocol to prepare a pure two-qubit state even when the thermal energy is substantially above the qubit energies and incorporate radiofrequency readout to achieve fidelities up to 99.34% for both readout and initialization. We also demonstrate single-qubit Clifford gate fidelities up to 99.85% and a two-qubit gate fidelity of 98.92%. These advances overcome the fundamental limitation that the thermal energy must be well below the qubit energies for the high-fidelity operation to be possible, surmounting a main obstacle in the pathway to scalable and fault-tolerant quantum computation., (© 2024. The Author(s).)

Background: Polyp recurrence is common after endoscopic mucosal resection (EMR) of non-pedunculated colonic polyps ≥ 20 mm. Two models haven been published for polyp recurrence prediction: Sydney EMR recurrence tool (SERT) and the size, morphology, colonic site, and access to target (SMSA) score. None of these models have been evaluated in a real-world United States (U.S.) cohort. We aimed to evaluate the external validity of these two models and develop a new model., Methods: Retrospective cohort study of patients with non-pedunculated polyps ≥ 20 mm that underwent EMR between 1/1/2012 and 6/30/2020. Univariate and multivariate analysis were performed to identify predictors of polyp recurrence to build a new model. Receiver Operating Characteristic (ROC) curves for the new model, SERT and a modified version of SMSA were derived and compared., Results: A total of 461 polyps from 461 unique patients were included for analysis. The average polyp size was 29.1 ± 12.4 mm. Recurrence rate at first or second surveillance colonoscopy was 29.0% at a 15.6 months median follow up (IQR 12.3-17.4). A model was created with 4 variables from index colonoscopy: size > 40 mm, tubulovillous adenoma histology, right colon location and piecemeal resection. ROC curves showed that the Area Under the ROC (AUC) for the new model was 0.618, for SERT 0.538 and for mSMSA 0.550., Conclusion: SERT score and mSMSA have poor external validity to predict polyp recurrence after EMR of non-pedunculated polyps > 20 mm. Our new model is simpler and performs better in this multiethnic, non-referral cohort from the U.S., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Video 1Closure of a refractory gastrocutaneous fistula with endoscopically guided percutaneous suturing with the use of miniature biopsy forceps., (© 2023 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc.)

Background: Endoscopic mucosal resection (EMR) is an effective method for removing non-pedunculated polyps ≥ 20 mm. We aimed to examine changes in EMR techniques over a 9-year period and evaluate frequency of histologic-confirmed recurrence., Methods: We identified patients who underwent EMR of non-pedunculated polyps ≥ 20 mm at a safety net and the Veteran's Affairs (VA) hospital in Houston, Texas between 2012 and 2020. Odds ratios (ORs) and 95% confidence intervals (CI) for associations with recurrence risk were estimated using multivariable logistic regression., Results: 461 unique patients were included. The histologic-confirmed recurrence was 29.0% at 15.6 months median follow up (IQR 12.3 - 17.4). Polyps removed between 2018 and 2020 had a 0.43 decreased odds of recurrence vs. polyps removed between 2012 and 2014. The use of viscous lifting agents increased over time (from 0 to 54%), and the use of saline was associated with increased risk of recurrence (OR 2.28 [CI 1.33 - 3.31])., Conclusions: Histologic-confirmed recurrence after EMR for non-pedunculated polyps ≥ 20 mm decreased over the seven year-period. Saline was associated with a higher risk of recurrence and the use of more viscous agents increased over time.

Once called a 'classically non-describable two-valuedness' by Pauli, the electron spin forms a qubit that is naturally robust to electric fluctuations. Paradoxically, a common control strategy is the integration of micromagnets to enhance the coupling between spins and electric fields, which, in turn, hampers noise immunity and adds architectural complexity. Here we exploit a switchable interaction between spins and orbital motion of electrons in silicon quantum dots, without a micromagnet. The weak effects of relativistic spin-orbit interaction in silicon are enhanced, leading to a speed up in Rabi frequency by a factor of up to 650 by controlling the energy quantization of electrons in the nanostructure. Fast electrical control is demonstrated in multiple devices and electronic configurations. Using the electrical drive, we achieve a coherence time T 2,Hahn  ≈ 50 μs, fast single-qubit gates with T π/2  = 3 ns and gate fidelities of 99.93%, probed by randomized benchmarking. High-performance all-electrical control improves the prospects for scalable silicon quantum computing., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Video 1Xxx., (© 2022 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc.)

Purpose of Review: Autoimmune gastritis is characterized by atrophy of acid secreting parietal cells resulting in achlorhydria. Upper gastrointestinal symptoms are common in autoimmune gastritis and frequently result in prescriptions for acid suppressant medications despite the inability of the stomach to secrete acid. Evidence-based recommendations for management of gastrointestinal symptoms in autoimmune gastritis are lacking., Recent Findings: The most common symptoms in patients with autoimmune gastritis are dyspepsia, heartburn, and regurgitation. Gastroesophageal reflux should be confirmed by pH-impedance testing and is typically weakly acid or alkaline. Therapy for reflux focuses on mechanical prevention of reflux (i.e., elevation of the head of the bed and alginates) or when severe, antireflux surgery. The etiology of dyspepsia in autoimmune gastritis is unclear and largely unstudied. In the first half of the 20th century, oral administration of acid to "aid digestion" was widely used with reported success. However, randomized, placebo-controlled trials are lacking. Here, we provide suggestions for attempting gastric acidification therapy., Summary: Upper GI symptoms are common in autoimmune gastritis. Their pathogenesis and therapy remain incompletely understood. Acid suppressant medications are useless and should be discontinued. A trial of acid replacement therapy is recommended especially in the form of placebo-controlled trials., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Goals and Background: Clinical staging with endoscopic ultrasound (EUS) and positron emission tomography (PET) is used to identify esophageal adenocarcinoma (EAC) patients with locally advanced disease and therefore, benefit from neoadjuvant therapy. However, EUS is operator dependent and subject to interobserver variability. Therefore, we aimed to identify clinical predictors of locally advanced EAC and build a predictive model that can be used as an adjunct to current staging methods., Study: This was a cross-sectional study of patients with EAC who underwent preoperative staging with EUS and PET scan followed by definitive therapy at our institution from January 2011 to December 2017. Demographic data, symptoms, endoscopic findings, EUS, and PET scan findings were obtained., Results: Four hundred and twenty-six patients met the study criteria, of which 86 (20.2%) patients had limited stage EAC and 340 (79.8%) had locally advanced disease. The mean age was 65.4±10.3 years of which 356 (83.6%) were men and 393 (92.3%) were White. On multivariable analysis, age (above 75 or below 65 y), dysphagia [odds ratio (OR): 2.84], weight loss (OR: 2.06), protruding tumor (OR: 2.99), and tumor size >2 cm (OR: 3.3) were predictive of locally advanced disease, while gastrointestinal bleeding (OR: 0.36) and presence of visible Barrett's esophagus (OR: 0.4) were more likely to be associated with limited stage. A nomogram for predicting the risk of locally advanced EAC was constructed and internally validated., Conclusions: We constructed a nomogram to facilitate an individualized prediction of the risk of locally advanced EAC. This model can aid in decision making for neoadjuvant therapy in EAC., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background In patients with resectable esophageal adenocarcinoma (EAC), the decision for neoadjuvant treatment depends on clinical staging with endoscopic ultrasound (EUS) and positron-emission tomography (PET) scan. Patients with locally advanced EAC pathology misclassified as early EAC by clinical staging are missing the opportunity to receive neoadjuvant therapy. We aim to identify predictors of locally advanced pathology in EAC to determine more accurately those who benefit from neoadjuvant therapy.  Methods Retrospective study of patients who underwent upfront endoscopic or surgical resection for EAC without neoadjuvant therapy from January 2011 to December 2017 was performed. Clinical characteristics, EUS, PET scan and histologic findings were analyzed. Multivariable analysis of predictors of locally advanced stage was performed and a risk prediction score was developed. Results A total of 97 patients were included; 68 patients were staged as early EAC (pT1 or pT2 and pN0) and 29 patients were staged as locally advanced EAC (pT1 or pT2 with pN1 and pT3 or pT4 irrespective of N status). In a predictive model of EAC, patients presenting with dysphagia, tumor size >2 cm, exophytic mass appearance on endoscopy and absence of hiatal hernia were more likely to be have locally advanced pathology with a probability of 70% (C-statistic 0.766). Conclusions A risk prediction model based on the presence of dysphagia, tumor size >2 cm, exophytic mass appearance and absence of hiatal hernia can be used to identify locally advanced pathology in EAC patients., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2021, Gomez Cifuentes et al.)