Fast charge sensing of Si/SiGe quantum dots via a high-frequency accumulation gate

Quantum dot arrays are a versatile platform for the implementation of spin qubits, as high-bandwidth sensor dots can be integrated with single-, double- and triple-dot qubits yielding fast and high-fidelity qubit readout. However, for undoped silicon devices, reflectometry off sensor ohmics suffers from the finite resistivity of the two-dimensional electron gas (2DEG), and alternative readout methods are limited to measuring qubit capacitance, rather than qubit charge. By coupling a surface-mount resonant circuit to the plunger gate of a high-impedance sensor, we realized a fast charge sensing technique that is compatible with resistive 2DEGs. We demonstrate this by acquiring at high speed charge stability diagrams of double- and triple-dot arrays in Si/SiGe heterostructures as well as pulsed-gate single-shot charge and spin readout with integration times as low as 2.4 $\mu$s.Comment: 10 pages, 5 figures, plus supplementary information with 9 pages and 6 figure

Single-electron control in a foundry-fabricated two-dimensional qubit array

Silicon spin qubits have achieved high-fidelity one- and two-qubit gates, above error correction thresholds, promising an industrial route to fault-tolerant quantum computation. A significant next step for the development of scalable multi-qubit processors is the operation of foundry-fabricated, extendable two-dimensional (2D) arrays. In gallium arsenide, 2D quantum-dot arrays recently allowed coherent spin operations and quantum simulations. In silicon, 2D arrays have been limited to transport measurements in the many-electron regime. Here, we operate a foundry-fabricated silicon 2x2 array in the few-electron regime, achieving single-electron occupation in each of the four gate-defined quantum dots, as well as reconfigurable single, double, and triple dots with tunable tunnel couplings. Pulsed-gate and gate-reflectometry techniques permit single-electron manipulation and single-shot charge readout, while the two-dimensionality allows the spatial exchange of electron pairs. The compact form factor of such arrays, whose foundry fabrication can be extended to larger 2xN arrays, along with the recent demonstration of coherent spin control and readout, paves the way for dense qubit arrays for quantum computation and simulation.Comment: 9 pages (including supplementary information and 5 figures

The need for new "patient-related" guidelines for the treatment of acute cholecystitis

Heterogeneity of patients affected by acute cholecystitis, and their co-morbidities make very difficult to standardize the therapy for this very common condition. The staging system suggested in the recent "Tokyo guidelines", did not show a relevant impact on the management of patients and on the outcome of the disease. The relation among local pathological picture, patient clinical status and treatment algorithm, has to be better studied

Towards the sustainable hydrogen production by catalytic conversion of C-laden biorefinery aqueous streams

An extensive screening of representative molecules of a post-hydrothermal process side stream has been performed with the aim of producing a gas mixture rich in hydrogen by catalytic aqueous phase reforming. The survey enlightens possible routes of valorisation of these by-products, scarcely investigated with other processes so far. The influence of reaction temperature was studied in the 230–270 °C range, looking at both the composition of the gas phase and the characterization of the liquid products. Indeed, the information coming from the condensed phase may provide relevant insights on the components that are not easily reformed, and that should be studied to improve the performance of the process. Binary and ternary mixtures of four selected compounds were tested to investigate synergistic and inhibiting effects, going towards the direction of a real biorefinery stream. The spent alumina-supported catalyst was characterized, outlining possible deactivation mechanisms of the catalytic system, and reused in two successive tests

Reflectometry of charge transitions in a silicon quadruple dot

Gate-controlled silicon quantum devices are currently moving from academic proof-of-principle studies to industrial fabrication, while increasing their complexity from single- or double-dot devices to larger arrays. We perform gate-based high-frequency reflectometry measurements on a 2x2 array of silicon quantum dots fabricated entirely using 300 mm foundry processes. Utilizing the capacitive couplings within the dot array, it is sufficient to connect only one gate electrode to one reflectometry resonator and still establish single-electron occupation in each of the four dots and detect single-electron movements with high bandwidth. A global top-gate electrode adjusts the overall tunneling times, while linear combinations of side-gate voltages yield detailed charge stability diagrams. We support our findings with $\mathbf{k}\cdot\mathbf{p}$ modeling and electrostatic simulations based on a constant interaction model, and experimentally demonstrate single-shot detection of interdot charge transitions with unity signal-to-noise ratios at bandwidths exceeding 30 kHz. Our techniques may find use in the scaling of few-dot spin-qubit devices to large-scale quantum processors.Comment: 10 pages including appendices and 7 figure

Intraoperative surgical site infection control and prevention : a position paper and future addendum to WSES intra-abdominal infections guidelines

Correction: Volume: 16 Issue: 1, Article Number: 18 DOI: 10.1186/s13017-021-00361-4Background Surgical site infections (SSI) represent a considerable burden for healthcare systems. They are largely preventable and multiple interventions have been proposed over past years in an attempt to prevent SSI. We aim to provide a position paper on Operative Room (OR) prevention of SSI in patients presenting with intra-abdominal infection to be considered a future addendum to the well-known World Society of Emergency Surgery (WSES) Guidelines on the management of intra-abdominal infections. Methods The literature was searched for focused publications on SSI until March 2019. Critical analysis and grading of the literature has been performed by a working group of experts; the literature review and the statements were evaluated by a Steering Committee of the WSES. Results Wound protectors and antibacterial sutures seem to have effective roles to prevent SSI in intra-abdominal infections. The application of negative-pressure wound therapy in preventing SSI can be useful in reducing postoperative wound complications. It is important to pursue normothermia with the available resources in the intraoperative period to decrease SSI rate. The optimal knowledge of the pharmacokinetic/pharmacodynamic characteristics of antibiotics helps to decide when additional intraoperative antibiotic doses should be administered in patients with intra-abdominal infections undergoing emergency surgery to prevent SSI. Conclusions The current position paper offers an extensive overview of the available evidence regarding surgical site infection control and prevention in patients having intra-abdominal infections.Peer reviewe

Perforated and bleeding peptic ulcer : WSES guidelines

Background Peptic ulcer disease is common with a lifetime prevalence in the general population of 5-10% and an incidence of 0.1-0.3% per year. Despite a sharp reduction in incidence and rates of hospital admission and mortality over the past 30 years, complications are still encountered in 10-20% of these patients. Peptic ulcer disease remains a significant healthcare problem, which can consume considerable financial resources. Management may involve various subspecialties including surgeons, gastroenterologists, and radiologists. Successful management of patients with complicated peptic ulcer (CPU) involves prompt recognition, resuscitation when required, appropriate antibiotic therapy, and timely surgical/radiological treatment. Methods The present guidelines have been developed according to the GRADE methodology. To create these guidelines, a panel of experts was designed and charged by the board of the WSES to perform a systematic review of the available literature and to provide evidence-based statements with immediate practical application. All the statements were presented and discussed during the 5th WSES Congress, and for each statement, a consensus among the WSES panel of experts was reached. Conclusions The population considered in these guidelines is adult patients with suspected complicated peptic ulcer disease. These guidelines present evidence-based international consensus statements on the management of complicated peptic ulcer from a collaboration of a panel of experts and are intended to improve the knowledge and the awareness of physicians around the world on this specific topic. We divided our work into the two main topics, bleeding and perforated peptic ulcer, and structured it into six main topics that cover the entire management process of patients with complicated peptic ulcer, from diagnosis at ED arrival to post-discharge antimicrobial therapy, to provide an up-to-date, easy-to-use tool that can help physicians and surgeons during the decision-making process.Peer reviewe

WSES consensus conference : Guidelines for firstline management of intra-abdominal infections

Peer reviewe

The acute phase management of spinal cord injury affecting polytrauma patients : the ASAP study

Publisher Copyright: © 2022, The Author(s).Background: Few data on the management of acute phase of traumatic spinal cord injury (tSCI) in patients suffering polytrauma are available. As the therapeutic choices in the first hours may have a deep impact on outcome of tSCI patients, we conducted an international survey investigating this topic. Methods: The survey was composed of 29 items. The main endpoints of the survey were to examine: (1) the hemodynamic and respiratory management, (2) the coagulation management, (3) the timing of magnetic resonance imaging (MRI) and spinal surgery, (4) the use of corticosteroid therapy, (5) the role of intraspinal pressure (ISP)/spinal cord perfusion pressure (SCPP) monitoring and (6) the utilization of therapeutic hypothermia. Results: There were 171 respondents from 139 centers worldwide. A target mean arterial pressure (MAP) target of 80–90 mmHg was chosen in almost half of the cases [n = 84 (49.1%)]. A temporary reduction in the target MAP, for the time strictly necessary to achieve bleeding control in polytrauma, was accepted by most respondents [n = 100 (58.5%)]. Sixty-one respondents (35.7%) considered acceptable a hemoglobin (Hb) level of 7 g/dl in tSCI polytraumatized patients. An arterial partial pressure of oxygen (PaO2) of 80–100 mmHg [n = 94 (55%)] and an arterial partial pressure of carbon dioxide (PaCO2) of 35–40 mmHg [n = 130 (76%)] were chosen in most cases. A little more than half of respondents considered safe a platelet (PLT) count > 100.000/mm3 [n = 99 (57.9%)] and prothrombin time (PT)/activated partial thromboplastin time (aPTT) < 1.5 times the normal control [n = 85 (49.7%)] in patients needing spinal surgery. MRI [n = 160 (93.6%)] and spinal surgery [n = 158 (92.4%)] should be performed after intracranial, hemodynamic, and respiratory stabilization by most respondents. Corticosteroids [n = 103 (60.2%)], ISP/SCPP monitoring [n = 148 (86.5%)], and therapeutic hypothermia [n = 137 (80%)] were not utilized by most respondents. Conclusions: Our survey has shown a great worldwide variability in clinical practices for acute phase management of tSCI patients with polytrauma. These findings can be helpful to define future research in order to optimize the care of patients suffering tSCI.Peer reviewe

The WSES/SICG/ACOI/SICUT/AcEMC/SIFIPAC guidelines for diagnosis and treatment of acute left colonic diverticulitis in the elderly

Acute left colonic diverticulitis (ALCD) in the elderly presents with unique epidemiological features when compared with younger patients. The clinical presentation is more nuanced in the elderly population, having higher in-hospital and postoperative mortality. Furthermore, geriatric comorbidities are a risk factor for complicated diverticulitis. Finally, elderly patients have a lower risk of recurrent episodes and, in case of recurrence, a lower probability of requiring urgent surgery than younger patients. The aim of the present work is to study age-related factors that may support a unique approach to the diagnosis and treatment of this problem in the elderly when compared with the WSES guidelines for the management of acute left-sided colonic diverticulitis. During the 1 degrees Pisa Workshop of Acute Care & Trauma Surgery held in Pisa (Italy) in September 2019, with the collaboration of the World Society of Emergency Surgery (WSES), the Italian Society of Geriatric Surgery (SICG), the Italian Hospital Surgeons Association (ACOI), the Italian Emergency Surgery and Trauma Association (SICUT), the Academy of Emergency Medicine and Care (AcEMC) and the Italian Society of Surgical Pathophysiology (SIFIPAC), three panel members presented a number of statements developed for each of the four themes regarding the diagnosis and management of ALCD in older patients, formulated according to the GRADE approach, at a Consensus Conference where a panel of experts participated. The statements were subsequently debated, revised, and finally approved by the Consensus Conference attendees. The current paper is a summary report of the definitive guidelines statements on each of the following topics: diagnosis, management, surgical technique and antibiotic therapy.Peer reviewe