https://www.selleckchem.com/HDAC.html 05). No differences in the failure patterns were found among groups. NaOCl+HEBP had no detrimental effect on the POBS of CSBC. The mixture of sodium hypochlorite and etidronic acid may be considered as an alternative irrigant when treating root perforations. The mixture of sodium hypochlorite and etidronic acid may be considered as an alternative irrigant when treating root perforations.This article presents secondary headache syndromes caused by life-threatening disease as well as symptomatic headaches requiring immediate treatment to prevent irreversible deficits. Clinical signs and symptoms indicating a secondary headache syndrome are summarized in the so-called SNOOP list (SNOOP systemic symptoms, neurological symptoms, acute onset, older patients and previous history). The main topic of this publication is the diagnostic procedure, with a discussion of the pitfalls of computed tomography and magnetic resonance imaging investigations and the specificities of other methods such as lumbar puncture and duplex sonography. The COVID-19 pandemic has drastically impacted postgraduate training programmes worldwide. This study aims to evaluate the Nigerian situation with respect to surgical training, with a view to identifying gaps and proffering solutions. A cross-sectional survey of surgical residents in Nigeria was conducted between 27 July 2020 and 14 August 2020. A structured questionnaire designed using the free software Google Forms was utilised for the study. The questionnaire was electronically distributed randomly to 250 surgical residents via emails and social media platforms including WhatsApp and Telegram. The data obtained was analysed by Google Forms . Ethical approval for the study was obtained from the ethics and research unit of the Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Osun State, Nigeria. At the end of the study period, 207 surgical residents completed and submitted the questionn