Pulsed power accelerator for material physics experiments

We have developed the design of Thor: a pulsed power accelerator that delivers a precisely shaped current pulse with a peak value as high as 7 MA to a strip-line load. The peak magnetic pressure achieved within a 1-cm-wide load is as high as 100 GPa. Thor is powered by as many as 288 decoupled and transit-time isolated bricks. Each brick consists of a single switch and two capacitors connected electrically in series. The bricks can be individually triggered to achieve a high degree of current pulse tailoring. Because the accelerator is impedance matched throughout, capacitor energy is delivered to the strip-line load with an efficiency as high as 50%. We used an iterative finite element method (FEM), circuit, and magnetohydrodynamic simulations to develop an optimized accelerator design. When powered by 96 bricks, Thor delivers as much as 4.1 MA to a load, and achieves peak magnetic pressures as high as 65 GPa. When powered by 288 bricks, Thor delivers as much as 6.9 MA to a load, and achieves magnetic pressures as high as 170 GPa. We have developed an algebraic calculational procedure that uses the single brick basis function to determine the brick-triggering sequence necessary to generate a highly tailored current pulse time history for shockless loading of samples. Thor will drive a wide variety of magnetically driven shockless ramp compression, shockless flyer plate, shock-ramp, equation of state, material strength, phase transition, and other advanced material physics experiments

Rituals and behaviours in the operating theatre and preventing infection. Using the evidence and consensus opinion to provide practical advice

There are existing evidence-based procedures and interventions undertaken pre- and peri-operatively to minimise surgical site infection (SSI), e.g. pre-operative surgical prophylaxis and minimising hypothermia. However, there are also many rituals and behaviours that take place in operating theatres (OT), that are derived from tradition, and custom rather than from evidence. To optimise patient care and efficiency in the use of resources, clinical guidelines are needed that are supported by whatever evidence is available. However, where there may be a degree of uncertainty regarding this evidence base, any advice that we or others provide should be characterised by integrity and a degree of humility. </p

Rituals and behaviours in the operating theatre - joint guidelines of the Healthcare Infection Society and the European Society of Clinical Microbiology and Infectious Diseases

Prevention of surgical site infection (SSI) remains a main priority in operating theatres. This has previously led to the introduction of practices, often referred to as ‘rituals’ and ‘behaviours’ and sometimes labelled as ‘myths’, that are controversial and frequently disputed. Some of them are not underpinned by sound scientific evidence, but they are established in everyday practice and considered by many as traditional to help ensure discipline and professionalism in the operating theatre. Previous Healthcare Infection Society guidelines were published 20 years ago, and they aimed to debunk some of the practices. Since then, new technologies have emerged, and an update was required. These new updated guidelines, produced in collaboration between the Healthcare Infection Society and the European Society of Clinical Microbiology and Infectious Diseases, used methodology accredited by the National Institute for Health and Care Excellence (NICE) to provide further advice on which practices are unnecessary. The guidelines are intended for an international audience. Specifically, they discuss the current available evidence for different rituals that are commonplace in the operating theatre, and highlight the gaps in knowledge with recommendations for future research. Previous guidelines divided the operating theatre rituals and behaviours into essential, preferable (optional), and those that provide no clear benefit. In the light of new evidence and in line with the new NICE principles for recommendations, these have been updated and are divided into recommendations for use, good practice points, and recommendations against certain practices. These updated guidelines aim to minimize ritualistic behaviour without increasing the risk of SSI. The guidelines do not focus on those key prevention practices that are well researched and shown to be effective in preventing SSI (e.g. preventing hypothermia). These well-researched topics are addressed in other guidelines, and the Working Party has based their guidelines on an assumption that these evidence-based recommendations are followed. </p

Rituals and behaviours in the operating theatre - joint guidelines of the Healthcare Infection Society and the European Society of Clinical Microbiology and Infectious Diseases

Prevention of surgical site infection (SSI) remains a main priority in operating theatres. This has previously led to the introduction of practices, often referred to as ‘rituals’ and ‘behaviours’ and sometimes labelled as ‘myths’, that are controversial and frequently disputed. Some of them are not underpinned by sound scientific evidence, but they are established in everyday practice and considered by many as traditional to help ensure discipline and professionalism in the operating theatre. Previous Healthcare Infection Society guidelines were published 20 years ago, and they aimed to debunk some of the practices. Since then, new technologies have emerged, and an update was required. These new updated guidelines, produced in collaboration between the Healthcare Infection Society and the European Society of Clinical Microbiology and Infectious Diseases, used methodology accredited by the National Institute for Health and Care Excellence (NICE) to provide further advice on which practices are unnecessary. The guidelines are intended for an international audience. Specifically, they discuss the current available evidence for different rituals that are commonplace in the operating theatre, and highlight the gaps in knowledge with recommendations for future research. Previous guidelines divided the operating theatre rituals and behaviours into essential, preferable (optional), and those that provide no clear benefit. In the light of new evidence and in line with the new NICE principles for recommendations, these have been updated and are divided into recommendations for use, good practice points, and recommendations against certain practices. These updated guidelines aim to minimize ritualistic behaviour without increasing the risk of SSI. The guidelines do not focus on those key prevention practices that are well researched and shown to be effective in preventing SSI (e.g. preventing hypothermia). These well-researched topics are addressed in other guidelines, and the Working Party has based their guidelines on an assumption that these evidence-based recommendations are followed. </p

Rituals and behaviours in the operating theatre and preventing infection. Using the evidence and consensus opinion to provide practical advice

There are existing evidence-based procedures and interventions undertaken pre- and peri-operatively to minimise surgical site infection (SSI), e.g. pre-operative surgical prophylaxis and minimising hypothermia. However, there are also many rituals and behaviours that take place in operating theatres (OT), that are derived from tradition, and custom rather than from evidence. To optimise patient care and efficiency in the use of resources, clinical guidelines are needed that are supported by whatever evidence is available. However, where there may be a degree of uncertainty regarding this evidence base, any advice that we or others provide should be characterised by integrity and a degree of humility. </p