421 research outputs found
High-frequency performance of Schottky source/drain silicon pMOS devices
A radio-frequency performance of 85-nm gate-length p-type Schottky barrier (SB) with PtSi source/drain materials is investigated. The impact of silicidation annealing temperature on the high-frequency behavior of SB MOSFETs is analyzed using an extrinsic small-signal equivalent circuit. It is demonstrated that the current drive and the gate transconductance strongly depend on the silicidation anneal temperature, whereas the unity-gain cutoff frequency of the measured devices remains nearly unchanged
Laser frequency locking by direct measurement of detuning
We present a new method of laser frequency locking in which the feedback
signal is directly proportional to the detuning from an atomic transition, even
at detunings many times the natural linewidth of the transition. Our method is
a form of sub-Doppler polarization spectroscopy, based on measuring two Stokes
parameters ( and ) of light transmitted through a vapor cell. This
extends the linear capture range of the lock loop by up to an order of
magnitude and provides equivalent or improved frequency discrimination as other
commonly used locking techniques.Comment: 4 pages, 4 figures Revte
Embedding robotic surgery into routine practice and impacts on communication and decision making: A review of the experience of surgical teams
While an increasing number of healthcare providers are purchasing surgical robots because of anticipated improvements in patient outcomes, their implementation into practice is highly variable. In robotic surgery, the surgeon is physically separated from the patient and the rest of the team with the potential to impact communication and decision making in the operating theatre and subsequently patient safety. Drawing on the approach of realist evaluation, in this article we review reports of the experience of surgical teams that have introduced robotic surgery to identify how and in what contexts robotic surgery is successfully integrated into practice and how and in what contexts it affects communication and decision making. Our analysis indicates that, while robotic surgery might bring about a number of benefits, it also creates new challenges. Robotic surgery is associated with increased operation duration, which has implications for patient safety, but strategies to reduce it can be effective with appropriate support from hospital administration and nursing management. The separation of the surgeon from the team can compromise communication but may be overcome through use of standardised communication. While surgeon situation awareness may be affected by the separation, the ergonomic benefits of robotic surgery may reduce stress and tiredness and enhance surgeon decision making. Our review adds to the existing literature by revealing strategies to support the introduction of robotic surgery and contextual factors that need to be in place for these to be effective
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Factors supporting and constraining the implementation of robot-assisted surgery: a realist interview study
YesTo capture stakeholders’ theories concerning how and in what contexts robot-assisted surgery becomes integrated into routine practice.
A literature review provided tentative theories that were revised through a realist interview study. Literature-based theories were presented to the interviewees, who were asked to describe to what extent and in what ways those theories reflected their experience. Analysis focused on identifying mechanisms through which robot-assisted surgery becomes integrated into practice and contexts in which those mechanisms are triggered.
Nine hospitals in England where robot-assisted surgery is used for colorectal operations.
Forty-four theatre staff with experience of robot-assisted colorectal surgery, including surgeons, surgical trainees, theatre nurses, operating department practitioners and anaesthetists.
Interviewees emphasised the importance of support from hospital management, team leaders and surgical colleagues. Training together as a team was seen as beneficial, increasing trust in each other’s knowledge and supporting team bonding, in turn leading to improved teamwork. When first introducing robot-assisted surgery, it is beneficial to have a handpicked dedicated robotic team who are able to quickly gain experience and confidence. A suitably sized operating theatre can reduce operation duration and the risk of de-sterilisation. Motivation among team members to persist with robot-assisted surgery can be achieved without involvement in the initial decision to purchase a robot, but training that enables team members to feel confident as they take on the new tasks is essential.
We captured accounts of how robot-assisted surgery has been introduced into a range of hospitals. Using a realist approach, we were also able to capture perceptions of the factors that support and constrain the integration of robot-assisted surgery into routine practice. We have translated these into recommendations that can inform future implementations of robot-assisted surgery
A realist process evaluation of robot-assisted surgery: integration into routine practice and impacts on communication, collaboration and decision-making
YesBackground: The implementation of robot-assisted surgery (RAS) can be challenging, with reports of surgical robots being underused. This raises questions about differences compared with open and laparoscopic surgery and how best to integrate RAS into practice. Objectives: To (1) contribute to reporting of the ROLARR (RObotic versus LAparoscopic Resection for Rectal cancer) trial, by investigating how variations in the implementation of RAS and the context impact outcomes; (2) produce guidance on factors likely to facilitate successful implementation; (3) produce guidance on how to ensure effective teamwork; and (4) provide data to inform the development of tools for RAS. Design: Realist process evaluation alongside ROLARR. Phase 1 – a literature review identified theories concerning how RAS becomes embedded into practice and impacts on teamwork and decision-making. These were refined through interviews across nine NHS trusts with theatre teams. Phase 2 – a multisite case study was conducted across four trusts to test the theories. Data were collected using observation, video recording, interviews and questionnaires. Phase 3 – interviews were conducted in other surgical disciplines to assess the generalisability of the findings. Findings: The introduction of RAS is surgeon led but dependent on support at multiple levels. There is significant variation in the training provided to theatre teams. Contextual factors supporting the integration of RAS include the provision of whole-team training, the presence of handpicked dedicated teams and the availability of suitably sized operating theatres. RAS introduces challenges for teamwork that can impact operation duration, but, over time, teams develop strategies to overcome these challenges. Working with an experienced assistant supports teamwork, but experience of the procedure is insufficient for competence in RAS and experienced scrub practitioners are important in supporting inexperienced assistants. RAS can result in reduced distraction and increased concentration for the surgeon when he or she is supported by an experienced assistant or scrub practitioner. Conclusions: Our research suggests a need to pay greater attention to the training and skill mix of the team. To support effective teamwork, our research suggests that it is beneficial for surgeons to (1) encourage the team to communicate actions and concerns; (2) alert the attention of the assistant before issuing a request; and (3) acknowledge the scrub practitioner’s role in supporting inexperienced assistants. It is beneficial for the team to provide oral responses to the surgeon’s requests. Limitations: This study started after the trial, limiting impact on analysis of the trial. The small number of operations observed may mean that less frequent impacts of RAS were missed. Future work: Future research should include (1) exploring the transferability of guidance for effective teamwork to other surgical domains in which technology leads to the physical or perceptual separation of surgeon and team; (2) exploring the benefits and challenges of including realist methods in feasibility and pilot studies; (3) assessing the feasibility of using routine data to understand the impact of RAS on rare end points associated with patient safety; (4) developing and evaluating methods for whole-team training; and (5) evaluating the impact of different physical configurations of the robotic console and team members on teamwork.National Inst for Health Research (NIHR
Eliciting context-mechanism-outcome configurations: Experiences from a realist evaluation investigating the impact of robotic surgery on teamwork in the operating theatre
This article recounts our experience of eliciting, cataloguing and prioritizing conjectured Context-Mechanism-Outcome configurations at the outset of a realist evaluation, to provide new insight into how Context-Mechanism-Outcome configurations can be generated and theorized. Our construction of Context-Mechanism-Outcome configurations centred on how, why and in what circumstances teamwork was impacted by robotic surgery, rather than how and why this technology improved surgical outcomes as intended. We found that, as well as offering resources, robotic surgery took away resources from the theatre team, by physically reconfiguring the operating theatre and redistributing the surgical task load, essentially changing the context in which teamwork was performed. We constructed Context-Mechanism-Outcome configurations that explain how teamwork mechanisms were both constrained by the contextual changes, and triggered in the new context through the use of informal strategies. We conclude by reflecting on our application of realist evaluation to understand the potential impacts of robotic surgery on teamwork
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Eliciting Context-Mechanism-Outcome configurations: Experiences from a realist evaluation investigating the impact of robotic surgery on teamwork in the operating theatre
YesThis article recounts our experience of eliciting, cataloguing and prioritizing conjectured Context-Mechanism-Outcome configurations at the outset of a realist evaluation, to provide new insight into how Context-Mechanism-Outcome configurations can be generated and theorized. Our construction of Context-Mechanism-Outcome configurations centred on how, why and in what circumstances teamwork was impacted by robotic surgery, rather than how and why this technology improved surgical outcomes as intended. We found that, as well as offering resources, robotic surgery took away resources from the theatre team, by physically reconfiguring the operating theatre and redistributing the surgical task load, essentially changing the context in which teamwork was performed. We constructed Context-Mechanism-Outcome configurations that explain how teamwork mechanisms were both constrained by the contextual changes, and triggered in the new context through the use of informal strategies. We conclude by reflecting on our application of realist evaluation to understand the potential impacts of robotic surgery on teamwork
Targeting miR-423-5p reverses exercise training–induced HCN4 channel remodeling and sinus bradycardia
Rationale: Downregulation of the pacemaking ion channel, HCN4 (hyperpolarization-activated cyclic nucleotide gated channel 4), and the corresponding ionic current, If, underlies exercise training–induced sinus bradycardia in rodents. If this occurs in humans, it could explain the increased incidence of bradyarrhythmias in veteran athletes, and it will be important to understand the underlying processes.
Objective: To test the role of HCN4 in the training-induced bradycardia in human athletes and investigate the role of microRNAs (miRs) in the repression of HCN4.
Methods and Results: As in rodents, the intrinsic heart rate was significantly lower in human athletes than in nonathletes, and in all subjects, the rate-lowering effect of the HCN selective blocker, ivabradine, was significantly correlated with the intrinsic heart rate, consistent with HCN repression in athletes. Next-generation sequencing and quantitative real-time reverse transcription polymerase chain reaction showed remodeling of miRs in the sinus node of swim-trained mice. Computational predictions highlighted a prominent role for miR-423-5p. Interaction between miR-423-5p and HCN4 was confirmed by a dose-dependent reduction in HCN4 3′-untranslated region luciferase reporter activity on cotransfection with precursor miR-423-5p (abolished by mutation of predicted recognition elements). Knockdown of miR-423-5p with anti-miR-423-5p reversed training-induced bradycardia via rescue of HCN4 and If. Further experiments showed that in the sinus node of swim-trained mice, upregulation of miR-423-5p (intronic miR) and its host gene, NSRP1, is driven by an upregulation of the transcription factor Nkx2.5.
Conclusions: HCN remodeling likely occurs in human athletes, as well as in rodent models. miR-423-5p contributes to training-induced bradycardia by targeting HCN4. This work presents the first evidence of miR control of HCN4 and heart rate. miR-423-5p could be a therapeutic target for pathological sinus node dysfunction in veteran athletes
Metabarcoding analysis on European coastal samples reveals new molecular metazoan diversity
Although animals are among the best studied organisms, we still lack a full description of their diversity, especially for microscopic taxa. This is partly due to the time-consuming and costly nature of surveying animal diversity through morphological and molecular studies of individual taxa. A powerful alternative is the use of high-throughput environmental sequencing, providing molecular data from all organisms sampled. We here address the unknown diversity of animal phyla in marine environments using an extensive dataset designed to assess eukaryotic ribosomal diversity among European coastal locations. A multi-phylum assessment of marine animal diversity that includes water column and sediments, oxic and anoxic environments, and both DNA and RNA templates, revealed a high percentage of novel 18S rRNA sequences in most phyla, suggesting that marine environments have not yet been fully sampled at a molecular level. This novelty is especially high among Platyhelminthes, Acoelomorpha, and Nematoda, which are well studied from a morphological perspective and abundant in benthic environments. We also identified, based on molecular data, a potentially novel group of widespread tunicates. Moreover, we recovered a high number of reads for Ctenophora and Cnidaria in the smaller fractions suggesting their gametes might play a greater ecological role than previously suspected
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