347 research outputs found

    The effect of compulsory face mask policies on community mobility in Germany

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    There is an ongoing debate about face masks being made compulsory in public spaces to contain COVID-19. A key concern is that such policies could undermine efforts to maintain social distancing and reduce mobility. We provide first evidence on the impact of compulsory face mask policies on community mobility. We exploit the staggered implementation of policies by German states during the first wave of the pandemic and measure mobility using geo-located smartphone data. We find that compulsory face mask policies led to a short-term reduction in community mobility, with no significant medium-term effects. We can rule out even small increases in mobility

    Mechanical analysis of cranial distractor attachment with three different resorbable fixation systems

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    Distraction osteogenesis (DO) has become increasingly popular to correct craniosynostosis. Disadvantages of DO include the secondary operation needed for device removal and titanium screw related dura injury. To reduce invasiveness of the secondary device removal operation and to overcome titanium-related problems, fixation of the cranial distractor with resorbable materials is a potential alternative. New resorbable fixation methods, such as ultrasound-activated pins (UAPs) or heat-activated pins (HAPs), allow faster attachment on thinner bone than conventional resorbable screws (CRSs) since tapping is not required. However, resorbable materials are designed to be attached with a resorbable plate, not with a titanium distractor. We evaluated the suitability of CRSs, HAPs and UAPs for the cranial distractor fixation in a laboratory setting with a mechanical testing machine. Fracture tests were conducted in two directions with respect to the longitudinal axis; vertical i.e. axial pull-out strength, and horizontal i.e. shear strength. Mean maximum pull-out strength for CRS, HAP and UAP was 48.9 N, 32.5 N and 14.7 N, respectively. Mean maximum shear strength for CRS, HAP and UAP was 40.8 N, 77.9 N and 38.9 N, respectively. According to our in vitro tests, the cranial distractor attachment with four CRSs or six HAPs per footplate would provide sufficient fixation stability. (C) 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Health-related quality of life after oncological resection and reconstruction of the chest wall

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    Objectives: There is limited information of the health-related quality of life (HRQoL) after surgical treatment of chest wall tumors. This cross-sectional study aimed to assess long-term HRQoL after chest wall reconstruction following oncological resection. Methods: Seventy-eight patients having undergone chest wall tumor resection and reconstruction during 1997-2015 were invited to complete the 15D and QLQ-C30 HRQoL instruments. Results: Altogether, 55 patients (17 men and 38 women), with a mean (SD) age of 68 (14) years, completed the questionnaires (response rate 71%). Patients had been operated due to soft tissue sarcoma (n=16), advanced breast cancer (n=15), osteo- or chondrosarcoma (n=14), or other tumor (n=10). Median time after primary surgery was 66 (IQR 38, 141) months. The resection was full thickness in 29/55 cases and partial thickness in 26/55 cases. Chest wall reconstruction was required for 47/55 cases (85%). Reconstruction was performed using soft-tissue flap in eight cases, skeletal stabilizations with mesh or mesh-cement-mesh (sandwich method) in 15 cases, and skeletal stabilizations and soft-tissue flap in 24 cases. Patients' mean 15D score (0.878, SD 0.111) was comparable to that of the age- and gender-standardized general population (0.891, SD 0.041). Limitations in breathing and usual activities were noted. The QLQ-C30 cancer-specific HRQoL was 72 points (maximum 100). Scores in the QLQ-C30 Functional scales ranged from 78 (Physical) to 91 (Social). Conclusions: Long-term HRQoL in patients after chest wall reconstruction following oncological resection is fair and comparable to that of the general population. Limitations in breathing and usual activities can occur. (C) 2019 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Clinical findings in relation to mortality in non-tuberculous mycobacterial infections : patients with Mycobacterium avium complex have better survival than patients with other mycobacteria

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    We compared the clinical findings and survival in patients with Mycobacterium avium complex (MAC) and other non-tuberculous mycobacteria (NTM). A total of 167 adult non-human immunodeficiency virus (HIV) patients with at least one positive culture for NTM were included. Medical records were reviewed. The patients were categorised according to the 2007 American Thoracic Society (ATS) criteria. MAC comprised 59 % of all NTM findings. MAC patients were more often female (70 % vs. 34 %, p <0.001) and had less fatal underlying diseases (23 % vs. 47 %, p = 0.001) as compared to other NTM patients. Symptoms compatible with NTM infection had lasted for less than a year in 34 % of MAC patients but in 54 % of other NTM patients (p = 0.037). Pulmonary MAC patients had a significantly lower risk of death compared to pulmonary other NTM (hazard ratio [HR] 0.50, 95 % confidence interval [CI] 0.33-0.77, p = 0.002) or subgroup of other slowly growing NTM (HR 0.55, 95 % CI 0.31-0.99, p = 0.048) or as rapidly growing NTM (HR 0.47, 95 % CI 0.25-0.87, p = 0.02). The median survival time was 13.0 years (95 % CI 5.9-20.1) for pulmonary MAC but 4.6 years (95 % CI 3.4-5.9) for pulmonary other NTM. Serious underlying diseases (HR 3.21, 95 % CI 2.05-5.01, p <0.001) and age (HR 1.07, 95 % CI 1.04-1.09, p <0.001) were the significant predictors of mortality and female sex was a predictor of survival (HR 0.38, 95 % CI 0.24-0.59, p <0.001) in the multivariate analysis. Pulmonary MAC patients had better prognosis than pulmonary other NTM patients. The symptom onset suggests a fairly rapid disease course.Peer reviewe

    Comparison of 'shallow' and 'deep' junction architectures for MBE-grown InAs/GaAs quantum dot solar cells

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    We report on the fabrication of InAs/GaAs quantum dot solar cells with high open circuit voltage by molecular beam epitaxy. `Shallow' and `deep' junction architectures were compared. The highest open circuit voltage of 0.94 V was obtained for the `shallow' junction configuration. The open circuit voltage of InAs quantum dot solar cells decreased only by ~40 mV compared to GaAs reference cells for both junction architectures indicating high quality quantum dots. The open circuit voltage of InAs/GaAs quantum dot solar cells was also found to be dependent on the size of quantum dots

    Elastic-plastic transition in MBE-grown GaSb semiconducting crystal examined by noindentation

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    The present paper concerns the elastic-plastic nanodeformation of Te-doped GaSb crystals grown by molecular beam epitaxy on the n-type of GaSb substrate. The conventional analysis of nanoindentation data obtained with sharp triangular (Berkovich) and spherical tip revealed the elastic modulus (E = 83:07 1:78 GPa), hardness (H = 5:19 0:25 GPa) and “true hardness” (HT = 5:73 0:04 GPa). The registered pop-in event which indicates the elastic–plastic transition in GaSb crystal points towards the corresponding yield strength ( Y = 3:8 0:1 GPa). The origin of incipient plasticity in GaSb crystal is discussed in terms of elastic-plastic deformation energy concept

    Treatment of compound tibia fracture with microvascular latissimus dorsi flap and the Ilizarov technique : A cross-sectional study of long-term outcomes

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    Background: Extensive compound tibial fractures present reconstructive challenges. The present study aimed to assess the outcomes of microvascular latissimus dorsi (LD) flap combined with the Ilizarov technique for extensive compound tibial fractures with bone loss and bone healing complications. Methods: Patient records were reviewed retrospectively. The Lower Extremity Functional Scale (LEFS), the Disabilities of the Arm, Hand and Shoulder (DASH), and the 15D health-related quality of life (HRQoL) instrument were applied. Results: Between 1989 and 2014, 16 patients underwent reconstruction with a microvascular LD flap and bone transport (11/16) or late bone lengthening (5/16). The mean clinical follow-up time was 6.6 (standard deviation (SD): 6.5) years. Three patients had minor complications requiring reoperation. Partial necrosis of one flap required late flap reconstruction in one case. Late bone grafting was used to enhance union in eight of 16 cases. The mean new bone gain was 3.8 cm (SD: 2.5). Overall, 11 patients completed the questionnaires in a mean of 22.3 years (SD: 2.4) after surgery. The main findings revealed a relatively good function of the reconstructed limb and good shoulder function. The mean HRQoL was comparable to that of an age-standardized sample of the general population. Conclusion: Segmental tibia transport and lengthening to correct limb length discrepancy do not compromise the microvascular muscle flap. Combined microvascular LD flap reconstruction and the Ilizarov technique can be used in treating acute compound tibial defects, pseudoarthrosis, and osteitis, all associated with significant amputation risk. Fair long-term functional outcomes and HRQoL are achieved when these combined techniques are used. (C) 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Force measurements during posterior calvarial vault osteodistraction : A novel measurement method

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    Posterior calvarial vault osteodistraction (PCVO) has become increasingly popular in the correction of craniosynostosis. When compared to cranioplasty, PCVO offers a shorter, less invasive operation, greater intracranial volume advancement and a lower rate of relapse. In general, distraction protocols are based primarily on clinical observations rather than systematic research. Faster distraction protocols may reduce complications. However, distraction protocols producing higher forces can increase complications. Thus, we need to understand these forces in order to improve distraction protocols and devices. We developed a force measurement method that can be used on PCVO devices. Here, we present preliminary data about the forces developed during PCVO. We measured the forces in four bicoronal craniosynostosis patients during PCVO. We observed a linear-like trend between the force increase and the distraction distance within distraction sessions. We also observed a step-wise force increase between distraction sessions and found that the distraction force relaxed rapidly shortly after the distraction session. The mean maximum pre distraction force for one distracter was 20.4 N, while the mean maximum end-distraction force for one distracter was 57.6 N. Our data suggests that current treatment protocols might be re-evaluated favouring shorter distraction distances and more frequent distraction sessions. (C) 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Assessment of the structural validity of three foot and ankle specific patient-reported outcome measures

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    Background: The structural validity of the Lower extremity functional scale (LEFS), the Visual analogue scale foot and ankle (VAS-FA), and the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) has not been compared earlier in patients after foot and ankle surgery. Methods: Altogether 165 previously operated patients completed the foot and ankle specific instruments, the 15D health-related quality of life (HRQoL) instrument, and general health (VAS). Results: The LEFS, the VAS-FA and the WOMAC had slight differences in their measurement properties. The VAS-FA had the best targeting and coverage. All three foot and ankle measures accounted for mobility and usual activities when compared to the different aspects of generic HRQoL. Conclusions: The LEFS, the VAS-FA and the WOMAC have relatively similar psychometric properties among foot and ankle patients, yet the VAS-FA provides the best targeting and coverage. (C) 2019 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.Peer reviewe
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