Optimal two-dimensional roughness for transition delay in high-speed boundary layer

The influence of surface roughness on transition to turbulence in a Mach 4.5 boundary layer is studied using direct numerical simulations. Transition is initiated by the nonlinearly most dangerous inflow disturbance, which causes the earliest possible breakdown on a flat plate for the prescribed inflow energy and Mach number. This disturbance is primarily comprised of two normal second-mode instability waves and an oblique first mode. When localized roughness is introduced, its shape and location relative to the synchronization points of the inflow waves are confirmed to have a clear impact on the amplification of the second-mode instabilities. The change in modal amplification coincides with the change in the height of the near-wall region where the instability wave-speed is supersonic relative to the mean flow; the net effect of a protruding roughness is destabilizing when placed upstream of the synchronization point and stabilizing when placed downstream. Assessment of the effect of the roughness location is followed by an optimization of the roughness height, abruptness and width with the objective of achieving maximum transition delay. The optimization is performed using an ensemble-variational (EnVar) approach, while the location of the roughness is fixed upstream of the synchronization points of the two second-mode waves. The optimal roughness disrupts the phase of the near-wall pressure waves, suppresses the amplification of the primary instability waves, and mitigates the nonlinear interactions that lead to breakdown to turbulence. The outcome is a sustained non-turbulent flow throughout the computational domain

Endoscopic repair of transsellar transsphenoidal meningoencephalocele; Case report and review of approaches

We present an extremely rare case of transsellar transsphenoidal meningoencephalocele in a 36-year-old woman with pituitary dwarfism complaining of nasal obstruction. Imaging studies showed a bony defect in the sellar floor and sphenoid sinus with huge nasopharyngeal mass and 3rd ventricle involvement. Using endoscopic endonasal approach the sac was partially removed and the defect was reconstructed with fat and fascial graft, and buttressed with titanium mesh and septal flap. Visual field improvement was noticed post-operatively and no complication was encountered during follow-up. So, endoscopic endonasal approach with partial resection of the sac is a safe and effective treatment for this disease. © 2015 The Authors. Published by Elsevier B.V

Penetrating Sacral Injury with a Wooden Foreign Body

Spinal penetrating trauma has a complex neurosurgical management. This study presents a 55-year-old male admitted in our center with a 1 � 1 centimeter laceration on the sacral area skin due to a wooden penetrating object. The computed tomography (CT) of the spine revealed a hypodense penetrating object that was introduced from the posterior aspect of the sacrum into dural space and then stopped in the S1 vertebral body. We performed a laminectomy of intact superior portion of the S1 lamina and released the wood from the surrounding bone, and finally, we pulled it out. © 2018 Arash Fattahi et al

Penetrating Sacral Injury with a Wooden Foreign Body

Spinal penetrating trauma has a complex neurosurgical management. This study presents a 55-year-old male admitted in our center with a 1 � 1 centimeter laceration on the sacral area skin due to a wooden penetrating object. The computed tomography (CT) of the spine revealed a hypodense penetrating object that was introduced from the posterior aspect of the sacrum into dural space and then stopped in the S1 vertebral body. We performed a laminectomy of intact superior portion of the S1 lamina and released the wood from the surrounding bone, and finally, we pulled it out. © 2018 Arash Fattahi et al

Delayed Effect of Dendritic Cells Vaccination on Survival in Glioblastoma: A Systematic Review and Meta‐Analysis

Background: Dendritic cell vaccination (DCV) strategies, thanks to a complex immune response, may flare tumor regression and improve patients’ long‐term survival. This meta‐analysis aims to assess the efficacy of DCV for newly diagnosed glioblastoma patients in clinical trials. Meth-ods: The study databases, including PubMed, Web of Knowledge, Google Scholar, Scopus, and Cochrane, were searched by two blinded investigators considering eligible studies based on the following keywords: “glioblastoma multiforme”, “dendritic cell”, “vaccination”, “immunother-apy”, “immune system”, “immune response”, “chemotherapy”, “recurrence”, and “te-mozolomide”. Among the 157 screened, only 15 articles were eligible for the final analysis. Results: Regimens including DCV showed no effect on 6‐month progression‐free survival (PFS, HR = 1.385, 95% CI: 0.822–2.335, p = 0.673) or on 6‐month overall survival (OS, HR = 1.408, 95% CI: 0.882–2.248, p = 0.754). In contrast, DCV led to significantly longer 1‐year OS (HR = 1.936, 95% CI: 1.396–2.85, p = 0.001) and longer 2‐year OS (HR = 3.670, 95% CI: 2.291–5.879, p = 0.001) versus control groups. Hence, introducing DCV could lead to increased 1 and 2‐year survival of patients by 1.9 and 3.6 times, respectively. Conclusion: Antitumor regimens including DCV can effectively improve mid-term survival in patients suffering glioblastoma multiforme (GBM), but its impact emerges only after one year from vaccination. These data indicate the need for more time to achieve an anti‐GBM immune response and suggest additional therapeutics, such as checkpoint inhibitors, to empower an earlier DCV action in patients affected by a very poor prognosis

Corrigendum to �Gamma Knife stereotactic radiosurgery for cerebellopontine angle meningioma� Clin. Neurol. Neurosurg. 187 (2019) 105557(S0303846719303531)(10.1016/j.clineuro.2019.105557)

The authors regret the author name Farid Kazemi was incorrectly instead of Foad Kazemi. Apparently, this occurred because of a name similarity with Farid Kazemi who is one of the main referring neurosurgeons. The authors would like to apologise for any inconvenience caused. © 2019 Elsevier B.V

Adjunctive treatment of myxopapillary ependymoma

Myxopapillary ependymoma are rare tumors and optimal therapeutic strategy is remained controversial. The main treatments for myxopapillary ependymoma tumors include surgery and radiotherapy. Hence, the present study aimed to review adjuvant treatment of myxopapillary ependymoma, focusing on spinal myxopapillary ependymoma. The information sources of all articles were the English authoritative databases including PubMed, Web of science, Scopus, Science direct and Google scholar. In this review study, the keywords including adjuvant, treatment, myxopapillary and ependymoma were selected from MeSH medical library. Related articles were published from 2000 to 2020. Given radiation tolerance in the spinal cord is 10-15 lower than that of the brain, it also should be noted that with increased dose and scope of therapeutic field, the corresponding risks are increased, as well. Also, chemotherapy has never been used as the primary treatment approach. Radiotherapy s value is considered while involving with sensitive areas where chemotherapy is also recommended. Gross total resection is the preferred primary treatment. © 2021 Page Press Publications. All rights reserved

A Synoptic- and Remote Sensing-based Analysis of a Severe Dust Storm Event over Central Asia

Published by [Verlag nicht ermittelbar], Taina

Neuropsychiatric manifestations of COVID-19 can be clustered in three distinct symptom categories

Several studies have reported clinical manifestations of the new coronavirus disease. However, few studies have systematically evaluated the neuropsychiatric complications of COVID-19. We reviewed the medical records of 201 patients with confirmed COVID-19 (52 outpatients and 149 inpatients) that were treated in a large referral center in Tehran, Iran from March 2019 to May 2020. We used clustering approach to categorize clinical symptoms. One hundred and fifty-one patients showed at least one neuropsychiatric symptom. Limb force reductions, headache followed by anosmia, hypogeusia were among the most common neuropsychiatric symptoms in COVID-19 patients. Hierarchical clustering analysis showed that neuropsychiatric symptoms group together in three distinct groups: anosmia and hypogeusia; dizziness, headache, and limb force reduction; photophobia, mental state change, hallucination, vision and speech problem, seizure, stroke, and balance disturbance. Three non-neuropsychiatric cluster of symptoms included diarrhea and nausea; cough and dyspnea; and fever and weakness. Neuropsychiatric presentations are very prevalent and heterogeneous in patients with coronavirus 2 infection and these heterogeneous presentations may be originating from different underlying mechanisms. Anosmia and hypogeusia seem to be distinct from more general constitutional-like and more specific neuropsychiatric symptoms. Skeletal muscular manifestations might be a constitutional or a neuropsychiatric symptom. © 2020, The Author(s)