203 research outputs found

    Fluctuating work in coherent quantum systems: proposals and limitations

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    One of the most important goals in quantum thermodynamics is to demonstrate advantages of thermodynamic protocols over their classical counterparts. For that, it is necessary to (i) develop theoretical tools and experimental set-ups to deal with quantum coherence in thermodynamic contexts, and to (ii) elucidate which properties are genuinely quantum in a thermodynamic process. In this short review, we discuss proposals to define and measure work fluctuations that allow to capture quantum interference phenomena. We also discuss fundamental limitations arising due to measurement back-action, as well as connections between work distributions and quantum contextuality. We hope the different results summarised here motivate further research on the role of quantum phenomena in thermodynamics.Comment: As a chapter of: F. Binder, L. A. Correa, C. Gogolin, J. Anders, and G. Adesso (eds.), "Thermodynamics in the quantum regime - Recent Progress and Outlook", (Springer International Publishing). Second version: Misspell in the title correcte

    Long‑term results of the augmented PFNA: a prospective multicenter trial

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    Producción CientíficaPertrochanteric fractures are increasing and their operative treatment remains under discussion. Failures needing reoperations such as a cut-out are reported to be high and are associated with multiple factors including poor bone quality, poor fracture reduction and improper implant placement. The PFNA® with perforated blade offers an option for standardized cement augmentation with a PMMA cement to provide more stability to the fracture fixation. It remains unclear if the augmentation of this implant does any harm in a longer time span. This prospective multicenter study shows clinical and radiological results with this implant with a mean follow-up time of 15 months

    Standardised cement augmentation of the PFNA using a perforated blade: A new technique and preliminary clinical results. A prospective multicentre trial

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    Producción CientíficaPertrochanteric fractures are a rising major health-care problem in the elderly and their operative stabilisation techniques are still under discussion. Furthermore, complications like cut-out are reported to be high and implant failure often is associated with poor bone quality. The PFNA1 with perforated blade offers a possibility for standardised cement augmentation using a polymethylmethacrylate (PMMA) cement which is injected through the perforated blade to enlarge the load-bearing surface and to diminish the stresses on the trabecular bone. The current prospective multicentre study was undertaken to evaluate the technical performance and the early clinical results of this new device. In nine European clinics, 59 patients (45 female, mean age 84.5 years) suffering from an osteoporotic pertrochanteric fracture (Arbeitsgemeinschaft fu¨ r Osteosynthesefragen, AO-31) were treated with the augmented PFNA1. Primary objectives were assessment of operative and postoperative complications, whereas activities of daily living, pain, mobility and radiologic parameters, such as cement distribution around the blade and the cortical thickness index, were secondary objectives. The mean follow-up time was 4 months where we observed callus healing in all cases. The surgical complication rate was 3.4% with no complication related to the cement augmentation. More than onehalf of the patients reached their prefracture mobility level within the study period. A mean volume of 4.2 ml of cement was injected. We did not find any cut-out, cut through, unexpected blade migration, implant loosening or implant breakage within the study period. Our findings lead us to conclude that the standardised cement augmentation using the perforated blade for pertrochanteric fracture fixation enhances the implant anchorage within the head–neck fragment and leads to good functional results

    The second law and beyond in microscopic quantum setups

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    The Clausius inequality (CI) is one of the most versatile forms of the second law. Although it was originally conceived for macroscopic steam engines, it is also applicable to quantum single particle machines. Moreover, the CI is the main connecting thread between classical microscopic thermodynamics and nanoscopic quantum thermodynamics. In this chapter, we study three different approaches for obtaining the CI. Each approach shows different aspects of the CI. The goals of this chapter are: (i) To show the exact assumptions made in various derivations of the CI. (ii) To elucidate the structure of the second law and its origin. (iii) To discuss the possibilities each approach offers for finding additional second-law like inequalities. (iv) To pose challenges related to the second law in nanoscopic setups. In particular, we introduce and briefly discuss the notions of exotic heat machines (X machines), and "lazy demons".Comment: As a chapter of: F. Binder, L. A. Correa, C. Gogolin, J. Anders, and G. Adesso (eds.), "Thermodynamics in the quantum regime - Recent Progress and Outlook", (Springer International Publishing). v1 does not include references to other book chapter

    Eradication of Acinetobacter baumannii/Enterobacter cloacae complex in an open proximal tibial fracture and closed drop foot correction with a multidisciplinary approach using the Taylor Spatial Frame®

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    Background Multi-drug-resistant bacteria (e.g. Carbapenem-resistant Acinetobacter baumannii, extended-spectrum betalactamase or carbapenemase-producing enterobacteriaceae) are emerging in early-onset infections. So far, there is no report describing the eradication of these bacteria in a osseous infection of an open proximal tibial fracture in combination with the hexapod technology to address both osseous consolidation and closed drop foot correction. Case presentation After sustaining a proximal tibial fracture (Gustilo 3B), a 41-year-old man was primarily treated with open reduction and internal fixation by a locking plate and split-thickness skin graft in the home country. At the time of admission to our hospital there was a significant anterolateral soft tissue defect covered with an already-necrotic split-thickness graft and suspicious secretion. CAT and MRI scans revealed no signs of osseous healing, intramedullary distinctive osteomyelitis, as well as a large abscess zone in the dorsal compartment. Multiple wound smears showed multi-drug-resistant bacteria: Acinetobacter baumannii (Carbapenem resistant) as well as Enterobacter cloacae complex (AmpC overexpression). After implant removal, excessive osseous and intramedullary debridements using the Reamer Irrigator Aspirator (RIA®) as well as initial negative pressure wound therapy were performed. Colistin hand-modelled chains and sticks were applied topically as well as an adjusted systemic antibiotic scheme was applied. After repetitive surgical interventions, the smears showed bacterial eradication and the patient underwent soft tissue reconstruction with a free vascularized latissimus dorsi muscle flap. External fixation was converted to a hexapod fixator (TSF®) to correct primary varus displacement, axial assignment and secure osseous healing. A second ring was mounted to address the fixed drop foot in a closed fashion without further intervention. At final follow-up, 12 months after trauma, the patient showed good functional recovery with osseous healing, intact soft tissue with satisfactory cosmetics and no signs of reinfection. Conclusions A multidisciplinary approach with orthopaedic surgeons for debridement, planning and establishing osseous and joint correction and consolidation, plastic surgeons for microvascular muscle flaps for soft tissue defect coverage as well as clinical microbiologists for the optimized anti-infective treatment is essential in these challenging rare cases

    Winkelstabile Plattenosteosynthese bei distalen periprothetischen Femurfrakturen : Klinisches Outcome und Mortalität

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    BACKGROUND The care of distal periprosthetic femoral fractures (PFF) is becoming a~major interdisciplinary challenge due to demographic developments. The operative treatment is often performed (depending on the type of fracture) by means of locking plate fixation (LPF), although little data on the clinical outcome exist by now. The aim of the study is to identify risk factors for a~poor outcome and increased mortality METHODS: In this retrospective study, 36 cases with distal PFF were examined. Exclusively treatment with LPF were included. Relevant previous illnesses (ASA score, Charlson index), fracture morphology and major complications were recorded as well as 1- and 3- year mortality. The clinical outcome was detected by using the Lysholm score. RESULTS The 1- and 3- year mortality were 9% and 26% - exclusively affecting ASA 3 and 4 patients. The Lysholm Score showed a high variability (65 ± 27~points) with higher values in the ASA 1-2 subgroup (82 vs. 63 points) but independent of fracture type. The preoperative ASA score, the Charlson comorbidity index, and the patient age were determined to be decisive for 3-year mortality. CONCLUSION This case series displayed a high absolute mortality even if the rate was slightly lower compared to previously published data. The rate of secondary dislocations, lack of fracture healing or follow-up operations were also low. The LPF therefore appears to be a suitable treatment for fractures with a stable prosthesis. However, there is a high variability in the clinical outcome regardless of the type of fracture and significantly increased mortality rates in previously ill patients

    Prevalence and Outcomes of Concomitant Aortic Stenosis and Cardiac Amyloidosis

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    Background: Older patients with severe aortic stenosis (AS) are increasingly identified to have cardiac amyloidosis (CA). It is unknown whether dual AS-CA has worse outcomes or results in futility of transcatheter aortic valve replacement (TAVR). / Objective: To identify clinical characteristics and outcomes of AS-CA compared to lone AS. / Methods: TAVR referrals at three international sites underwent blinded research-corelab 99mTc-DPD bone scintigraphy (Perugini Grade-0 negative, 1–3 increasingly positive) prior to intervention. Transthyretin-CA (ATTR) was diagnosed by DPD and absence of a clonal immunoglobulin, and light-chain-CA (AL) via tissue biopsy. National registries captured all-cause mortality. / Results: 407 patients (83.4±6.5 years, 49.8% male) were recruited. DPD was positive in n=48 (11.8%, Grade-1 3.9%[n=16] Grade-2/3 7.9%[n=32]); AL was diagnosed in one Grade-1. Grade-2/3 patients had worse functional capacity, biomarkers (NT-proBNP/hsTnT), and bi-ventricular remodeling. A clinical score (RAISE) using left-ventricular Remodeling (hypertrophy/diastolic dysfunction), Age, Injury (hsTnT), Systemic involvement, and Electrical abnormalities (RBBB/low-voltages) was developed to predict AS-CA presence (AUC 0.86, 95%CI 0.78-0.94, p<0.001). Heart Team decision (DPD-blinded) resulted in TAVR (333[81.6%]), surgical-AVR (10[2.5%]), or medical management (65[15.9%]). After median 1.7 years, 23% of patients had died. 1-year mortality was worse in all-comers AS-CA (Grade-1-3) than lone AS (24.5 vs 13.9%, p=0.05). TAVR improved survival versus medical management with AS-CA survival post-TAVR no different to lone AS (p=0.36). / Conclusion: Dual pathology of AS-CA is common in older AS patients and can be predicted clinically. AS-CA has worse clinical presentation and a trend towards worse prognosis, unless treated. TAVR should therefore not be withheld in AS-CA
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