The Pre-Stall Behavior of a 4-Stage Transonic Compressor and Stall Monitoring Based on Artificial Neural Networks

Current research concerned with the aerodynamic instability of compressors aims at an extension of the operating range of the compressor towards decreased massflow. In practice, a safety margin is maintained between operating point and stability limit to prevent the compressor from going into stall and surge. In this article, we analyze the behavior of a 4-stage transonic axial compressor before entering the unstable range and present an approach to identifying incipient surge and stall using artificial neural networks. This method is based on measurements of the unsteady static wall pressure in front of the first rotor

Interdisciplinary Decision Making in Hemorrhagic Stroke Based on CT Imaging—Differences Between Neurologists and Neurosurgeons Regarding Estimation of Patients' Symptoms, Glasgow Coma Scale, and National Institutes of Health Stroke Scale

Background and Purpose: Acute intracerebral hemorrhage (ICH) requires rapid decision making toward neurosurgery or conservative neurological stroke unit treatment. In a previous study, we found overestimation of clinical symptoms when clinicians rely mainly on cerebral computed tomography (cCT) analysis. The current study investigates differences between neurologists and neurosurgeons estimating specific scores and clinical symptoms. Methods: Overall, 14 neurologists and 15 neurosurgeons provided clinical estimates and National Institutes of Health Stroke Scale (NIHSS) as well as Glasgow Coma Scale (GCS) based on cCT images and basic information of 50 patients with hypertensive and lobar ICH. Subgroup analyses were performed for the different professions (neurologists vs. neurosurgeons) and bleeding subtypes (typical location vs. atypical). The differences between the actual GCS and NIHSS scores and the cCT-imaging-based estimated scores were depicted as Bland-Altman plots and negative and positive predictive value (NPV and PPV) for prediction of clinical relevant items. Delta NIHSS points (Delta GCS points) were calculated as the difference between actual and rated NIHSS (GCS) including 95% confidence interval (CI). Results: Mean Delta GCS points for neurosurgeons was 1.16 (95% CI: -2.67-4.98); for neurologists, 0.99 (95% CI: -2.58-4.55), p = 0.308; mean Delta NIHSS points for neurosurgeons was -2.95 (95% CI: -12.71-6.82); for neurologists, -0.33 (95% CI: -9.60-8.94), p < 0.001. NPV and PPV for stroke symptoms were low, with large differences between different symptoms, bleeding subtypes, and professions. Both professions had more problems in proper rating of specific clinic-neurological symptoms than rating scores. Conclusion: Our results stress the need for joint decision making based on detailed neurological examination and neuroimaging findings also in telemedicine

Autologous haematopoietic stem cell transplantation for multiple sclerosis: a position paper and registry outline

Background: While substantial progress has been made in the development of disease-modifying medications for multiple sclerosis (MS), a high percentage of treated patients still show progression and persistent inflammatory activity. Autologous haematopoietic stem cell transplantation (AHSCT) aims at eliminating a pathogenic immune repertoire through intense short-term immunosuppression that enables subsequent regeneration of a new and healthy immune system to re-establish immune tolerance for a long period of time. A number of mostly open-label, uncontrolled studies conducted over the past 20 years collected about 4000 cases. They uniformly reported high efficacy of AHSCT in controlling MS inflammatory disease activity, more markedly beneficial in relapsing-remitting MS. Immunological studies provided evidence for qualitative immune resetting following AHSCT. These data and improved safety profiles of transplantation procedures spurred interest in using AHSCT as a treatment option for MS. Objective: To develop expert consensus recommendations on AHSCT in Germany and outline a registry study project. Methods: An open call among MS neurologists as well as among experts in stem cell transplantation in Germany started in December 2021 to join a series of virtual meetings. Results: We provide a consensus-based opinion paper authored by 25 experts on the up-to-date optimal use of AHSCT in managing MS based on the Swiss criteria. Current data indicate that patients who are most likely to benefit from AHSCT have relapsing-remitting MS and are young, ambulatory and have high disease activity. Treatment data with AHSCT will be collected within the German REgistry Cohort of autologous haematopoietic stem CeLl trAnsplantation In MS (RECLAIM). Conclusion: Further clinical trials, including registry-based analyses, are urgently needed to better define the patient characteristics, efficacy and safety profile of AHSCT compared with other high-efficacy therapies and to optimally position it as a treatment option in different MS disease stages. Keywords: Autologous haematopoietic stem cell transplantation (AHSCT), multiple sclerosis, registry study, treatment recommendation

RNOP-09: Pegylated liposomal doxorubicine and prolonged temozolomide in addition to radiotherapy in newly diagnosed glioblastoma - a phase II study

BACKGROUND: Although Temozolomide is effective against glioblastoma, the prognosis remains dismal and new regimens with synergistic activity are sought for. METHODS: In this phase-I/II trial, pegylated liposomal doxorubicin (Caelyx, PEG-Dox) and prolonged administration of Temozolomide in addition to radiotherapy was investigated in 63 patients with newly diagnosed glioblastoma. In phase-I, PEG-Dox was administered in a 3-by-3 dose-escalation regimen. In phase-II, 20 mg/m2 PEG-Dox was given once prior to radiotherapy and on days 1 and 15 of each 28-day cycle starting 4 weeks after radiotherapy. Temozolomide was given in a dose of 75 mg/m2 daily during radiotherapy (60 Gy) and 150-200 mg/m2 on days 1-5 of each 28-day cycle for 12 cycles or until disease progression. RESULTS: The toxicity of the combination of PEG-Dox, prolonged administration of Temozolomide, and radiotherapy was tolerable. The progression free survival after 12 months (PFS-12) was 30.2%, the median overall survival was 17.6 months in all patients including the ones from Phase-I. None of the endpoints differed significantly from the EORTC26981/NCIC-CE.3 data in a post-hoc statistical comparison. CONCLUSION: Together, the investigated combination is tolerable and feasible. Neither the addition of PEG-Dox nor the prolonged administration of Temozolomide resulted in a meaningful improvement of the patient's outcome as compared to the EORTC26981/NCIC-CE.3 data

Selective cancer-germline gene expression in pediatric brain tumors

Cancer-germline genes (CGGs) code for immunogenic antigens that are present in various human tumors and can be targeted by immunotherapy. Their expression has been studied in a wide range of human tumors in adults. We measured the expression of 12 CGGs in pediatric brain tumors, to identify targets for therapeutic cancer vaccines. Real Time PCR was used to quantify the expression of genes MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A6, MAGE-A10, MAGE-A12, MAGE-C2, NY-ESO-1 and GAGE-1,2,8 in 50 pediatric brain tumors of different histological subtypes. Protein expression was examined with immunohistochemistry. Fifty-five percent of the medulloblastomas (n = 11), 86% of the ependymomas (n = 7), 40% of the choroid plexus tumors (n = 5) and 67% of astrocytic tumors (n = 27) expressed one or more CGGs. Immunohistochemical analysis confirmed qPCR results. With exception of a minority of tumors, the overall level of CGG expression in pediatric brain tumors was low. We observed a high expression of at least one CGG in 32% of the samples. CGG-encoded antigens are therefore suitable targets in a very selected group of pediatric patients with a brain tumor. Interestingly, glioblastomas from adult patients expressed CGGs more often and at significantly higher levels compared to pediatric glioblastomas. This observation is in line with the notion that pediatric and adult glioblastomas develop along different genetic pathways

Decomposition phenomena of Zn13 Sb10 under working conditions of thermoelectric generators and maximum current densities for electromigration

The mixed ionic-electronic conductor (MIEC) Zn13−δSb10 is a thermoelectric material with high performance at intermediate temperatures and contains only abundant elements. This work evaluates its suitability for thermoelectric applications with respect to thermal instability and decomposition by electromigration of Zn under current flow. In addition to the formation of Zn whiskers, this migration often leads to cracks. Thermoelectric measurements of bulk Zn13−δSb10 (δ ∼ 0.2) prepared by a slow cooling method show zT values of 0.7 at 200 °C. A series of tests under flowing currents with different voltages and current densities on bar-shaped samples was followed by the space-resolved investigation of their composition and its systematical correlation with the Seebeck coefficient. The latter increases upon Zn depletion, especially when ZnSb is formed. At room temperature (RT), Zn migration starts at a voltage of ∼0.01 V, which is much lower than for other MIECs like copper chalcogenides. At higher electrical fields, which may be enhanced by the Seebeck voltage, the amount of deposited Zn at the negative pole increases with the current density even if the transported charge is kept constant