23 research outputs found

    Spectral phase encoding for data storage and addressing

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    We propose to use a broad-bandwidth laser source for storing and retrieving multiple holograms in a photorefractive material. Each storage address is defined by a specific spectral encoding of the reference beam. The validity of the spectral encoding method is tested in a preliminary experiment

    Casemix, management, and mortality of patients receiving emergency neurosurgery for traumatic brain injury in the Global Neurotrauma Outcomes Study: a prospective observational cohort study

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    An innovative ovine model of severe cardiopulmonary failure supported by veno-arterial extracorporeal membrane oxygenation

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    Abstract Refractory cardiogenic shock (CS) often requires veno-arterial extracorporeal membrane oxygenation (VA-ECMO) to sustain end-organ perfusion. Current animal models result in heterogenous cardiac injury and frequent episodes of refractory ventricular fibrillation. Thus, we aimed to develop an innovative, clinically relevant, and titratable model of severe cardiopulmonary failure. Six sheep (60 ± 6 kg) were anaesthetized and mechanically ventilated. VA-ECMO was commenced and CS was induced through intramyocardial injections of ethanol. Then, hypoxemic/hypercapnic pulmonary failure was achieved, through substantial decrease in ventilatory support. Echocardiography was used to compute left ventricular fractional area change (LVFAC) and cardiac Troponin I (cTnI) was quantified. After 5 h, the animals were euthanised and the heart was retrieved for histological evaluations. Ethanol (58 ± 23 mL) successfully induced CS in all animals. cTnI levels increased near 5000-fold. CS was confirmed by a drop in systolic blood pressure to 67 ± 14 mmHg, while lactate increased to 4.7 ± 0.9 mmol/L and LVFAC decreased to 16 ± 7%. Myocardial samples corroborated extensive cellular necrosis and inflammatory infiltrates. In conclusion, we present an innovative ovine model of severe cardiopulmonary failure in animals on VA-ECMO. This model could be essential to further characterize CS and develop future treatments

    Procedures performed during neurosurgery residency in Europe

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    Background: In a previous article (https://doi.org/10.1007/s00701-019-03888-3), preliminary results of a survey, aiming to shed light on the number of surgical procedures performed and assisted during neurosurgery residency in Europe were reported. We here present the final results and extend the analyses. Methods: Board-certified neurosurgeons of European Association of Neurosurgical Societies (EANS) member countries were asked to review their residency case logs and participate in a 31-question electronic survey (SurveyMonkey Inc., San Mateo, CA). The responses received between April 25, 2018, and April 25, 2020, were considered. We excluded responses that were incomplete, from non-EANS member countries, or from respondents that have not yet completed their residency. Results: Of 430 responses, 168 were considered for analysis after checking in- and exclusion criteria. Survey responders had a mean age of 42.7 ± 8.8 years, and 88.8% were male. Responses mainly came from surgeons employed at university/teaching hospitals (85.1%) in Germany (22.0%), France (12.5%), the United Kingdom (UK; 8.3%), Switzerland (7.7%), and Greece (7.1%). Most responders graduated in the years between 2011 and 2019 (57.7%). Thirty-eight responders (22.6%) graduated before and 130 responders (77.4%) after the European WTD 2003/88/EC came into effect. The mean number of surgical procedures performed independently, supervised or assisted throughout residency was 540 (95% CI 424–657), 482 (95% CI 398–568), and 579 (95% CI 441–717), respectively. Detailed numbers for cranial, spinal, adult, and pediatric subgroups are presented in the article. There was an annual decrease of about 33 cases in total caseload between 1976 and 2019 (coeff. − 33, 95% CI − 62 to − 4, p = 0.025). Variables associated with lesser total caseload during residency were training abroad (1210 vs. 1747, p = 0.083) and female sex by trend (947 vs. 1671, p = 0.111), whereas case numbers were comparable across the EANS countries (p = 0.443). Conclusion: The final results of this survey largely confirm the previously reported numbers. They provide an opportunity for current trainees to compare their own case logs with. Again, we confirm a significant decline in surgical exposure during training between 1976 and 2019. In addition, the current analysis reveals that female sex and training abroad may be variables associated with lesser case numbers during residency
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