Vacancies and vacancy-oxygen complexes in silicon: Positron annihilation with core electrons

ABSTRACT: Various point defects in silicon are studied theoretically from the point view of positron annihilation spectroscopy. Properties of a positron trapped at a single vacancy, divacancy, vacancy-oxygen complexes (VOn), and divacancy-oxygen complex are investigated. In addition to the positron lifetime and positron binding energy to defects, we also calculate the momentum distribution of annihilation photons (MDAP) for high momenta, which has been recently shown to be a useful quantity for defect identification in semiconductors. The influence of atomic relaxations around defects on positron properties is also examined. Mutual differences among the high momentum parts of the MDAP for various defects studied are mostly considerable, which can be used for the experimental defect determination

Management of Bleeding and Hemolysis During Percutaneous Microaxial Flow Pump Support A Practical Approach

© 2023 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Percutaneous ventricular assist devices (pVADs) are increasingly being used because of improved experience and availability. The Impella (Abiomed), a percutaneous microaxial, continuous-flow, short-term ventricular assist device, requires meticulous postimplantation management to avoid the 2 most frequent complications, namely, bleeding and hemolysis. A standardized approach to the prevention, detection, and treatment of these complications is mandatory to improve outcomes. The risk for hemolysis is mostly influenced by pump instability, resulting from patient- or device-related factors. Upfront echocardiographic assessment, frequent monitoring, and prompt intervention are essential. The precarious hemostatic balance during pVAD support results from the combination of a procoagulant state, due to critical illness and contact pathway activation, together with a variety of factors aggravating bleeding risk. Preventive strategies and appropriate management, adapted to the impact of the bleeding, are crucial. This review offers a guide to physicians to tackle these device-related complications in this critically ill pVAD-supported patient population.Peer reviewe

ECMO for COVID-19 patients in Europe and Israel

Since March 15th, 2020, 177 centres from Europe and Israel have joined the study, routinely reporting on the ECMO support they provide to COVID-19 patients. The mean annual number of cases treated with ECMO in the participating centres before the pandemic (2019) was 55. The number of COVID-19 patients has increased rapidly each week reaching 1531 treated patients as of September 14th. The greatest number of cases has been reported from France (n = 385), UK (n = 193), Germany (n = 176), Spain (n = 166), and Italy (n = 136) .The mean age of treated patients was 52.6 years (range 16–80), 79% were male. The ECMO configuration used was VV in 91% of cases, VA in 5% and other in 4%. The mean PaO2 before ECMO implantation was 65 mmHg. The mean duration of ECMO support thus far has been 18 days and the mean ICU length of stay of these patients was 33 days. As of the 14th September, overall 841 patients have been weaned from ECMO support, 601 died during ECMO support, 71 died after withdrawal of ECMO, 79 are still receiving ECMO support and for 10 patients status n.a. . Our preliminary data suggest that patients placed on ECMO with severe refractory respiratory or cardiac failure secondary to COVID-19 have a reasonable (55%) chance of survival. Further extensive data analysis is expected to provide invaluable information on the demographics, severity of illness, indications and different ECMO management strategies in these patients

Indications for primary rotating-hinge total knee arthroplasty. Is there consensus?

The use of rotating-hinge systems in total knee arthroplasty is most often seen in revision setting where excessive bone loss, ligamentous instability and/or extensor mechanism dysfunction may necessitate an increased level of component constraint. However, this implant type is also being increasingly used in the primary setting. The aim of this study is to review literature concerning the use of third generation rotating-hinge devices focusing on the indications for primary cases.Literature was searched for following search terms: total knee arthroplasty, primary indication, constraint, rotating hinge knee, knee prosthesis, hinged knee, total knee replacement. Additional papers were identified by screening references and similar articles. All papers dealing with first or second generation rotating-hinge implants and revision cases were discarded.After conducting a large literature search, we concluded that third generation rotating-hinge implants should be considered in limited indications in which ligamentous tibiofemoral instability is the core indication

Indications for primary rotating-hinge total knee arthroplasty. Is there consensus?

The use of rotating-hinge systems in total knee arthroplasty is most often seen in revision setting where excessive bone loss, ligamentous instability and/ or extensor mechanism dysfunction may necessitate an increased level of component constraint. However, this implant type is also being increasingly used in the primary setting. The aim of this study is to review literature concerning the use of third generation rotating-hinge devices focusing on the indications for primary cases. Literature was searched for following search terms: total knee arthroplasty, primary indication, constraint, rotating hinge knee, knee prosthesis, hinged knee, total knee replacement. Additional papers were identified by screening references and similar articles. All papers dealing with first or second generation rotating-hinge implants and revision cases were discarded. After conducting a large literature search, we concluded that third generation rotating-hinge implants should be considered in limited indications in which ligamentous tibiofemoral instability is the core indication.status: publishe

Late Presentation of an Iatrogenic Pseudoaneurysm of the Profunda Femoris Artery following Intramedullary Nailing

Introduction. Hip fractures are one of the most common osteoporotic fractures, and the incidence is expected to increase in the future. Vascular injury of the femoral vessels, although uncommon, is an intermittently reported complication in the treatment of proximal femoral fractures. This may be iatrogenic or less frequently as a result of the fracture itself. The profunda femoris artery is most commonly involved, probably because of its close relationship to the femur in the subtrochanteric region. Case Presentation. We report a well-documented case of pseudoaneurysm of the profunda femoris artery after intramedullary nailing of an intertrochanteric femoral fracture. Arterial damage was due to overpenetration when drilling the distal locking hole. Because of the late presentation, pressure on the medial femoral diaphysis caused severe cortical scalloping. This resulted in an obvious radiographic image rarely reported before. Conclusion. This case report illustrates the uncommon complication of pseudoaneurysm after intramedullary hip nailing. Because of the risk of potentially limb- and life-threatening complications, we advise careful drilling and placement of the distal locking screw. Excessive screw length should be avoided. The injured limb should be returned to the neutral position and lower-limb traction should be reduced before drilling the distal locking hole

Propofol-infusion syndrome in traumatic brain injury: consider the ECMO option

status: publishe

Short-term outcome trapeziectomy with ligament reconstruction and tendon interposition versus trapeziometacarpal prosthesis: a literature review

Background: Trapeziectomy with ligament reconstruction and tendon interposition and trapeziometacarpal prosthesis are two commonly used procedures for first carpometacarpal joint osteoarthritis. The purpose of this study is to compare the short-term outcome of trapeziectomy with ligament reconstruction and tendon interposition to trapeziometacarpal prosthesis. Methods: Pubmed, Cochrane library and science direct database were searched with adequate search terms. Used parameters were force, pain, mobility, functionality and complication. All papers describing the short-term outcome of ligament reconstruction and tendon interposition or trapeziometacarpal prosthesis were included in this review.Results: Trapeziometacarpal prostheses showed faster pain relief compared with trapeziectomy and ligament reconstruction and tendon interposition. Overall, there was a better strength in the trapeziometacarpal prosthesis group. A lack of information was found about the short-term functionality. The mobility recovers faster in the prosthesis group, although different scoring scales were used for measurement.Conclusion: We could confirm the faster pain relief in the prosthesis group and generally a faster recovery of strength and mobility. In the prosthesis group were more short-term complications. More studies are required to evaluate the short-term recovery of strength, the mobility, functionality and satisfaction