Assessment of trace metal contamination in a historical freshwater canal (Buckingham Canal), Chennai, India

The present study was done to assess the sources and the major processes controlling the trace metal distribution in sediments of Buckingham Canal. Based on the observed geochemical variations, the sediments are grouped as South Buckingham Canal and North Buckingham Canal sediments (SBC and NBC, respectively). SBC sediments show enrichment in Fe, Ti, Mn, Cr, V, Mo, and As concentrations, while NBC sediments show enrichment in Sn, Cu, Pb, Zn, Ni, and Hg. The calculated Chemical Index of Alteration and Chemical Index of Weathering values for all the sediments are relatively higher than the North American Shale Composite and Upper Continental Crust but similar to Post-Archaean Average Shale, and suggest a source area with moderate weathering. Overall, SBC sediments are highly enriched in Mo, Zn, Cu, and Hg (geoaccumulation index (Igeo) class 4– 6), whereas NBC sediments are enriched in Sn, Cu,Zn, and Hg (Igeo class 4–6). Cu, Ni, and Cr show higher than Effects-Range Median values and hence the biological adverse effect of these metals is 20%; Zn, which accounts for 50%, in the NBC sediments, has a more biological adverse effect than other metalsfound in these sediments. The calculated Igeo, Enrichment Factor, and Contamination Factor values indicate that Mo, Hg, Sn, Cu, and Zn are highly enriched in the Buckingham Canal sediments, suggesting the rapid urban and industrial development of Chennai MetropolitanCity have negatively influenced on the surrounding aquatic ecosystem

CSF Rhinorrhea After Endonasal Intervention to the Skull Base (CRANIAL) — Part 2:Impact of COVID-19

Background During the pandemic, there has been a concern about the increased risk of perioperative mortality for patients with COVID-19, and the transmission risk to healthcare workers, particularly during endonasal neurosurgical operations. The Pituitary Society produced recommendations to guide management during this era. We sought to assess contemporary neurosurgical practice and the impact of COVID-19. Methods A multicentre, prospective, observational cohort study was conducted at twelve tertiary neurosurgical units (UK and Ireland). Data were collected from March 23rd-July 31st, 2020 inclusive. Data points collected were patient demographics, pre-operative COVID-19 testing, intra-operative operative modifications, and 30-day COVID infection rates. Results 124 patients were included. 116 patients (n=116/124, 94%) underwent COVID-19 testing pre-operatively (TSA: 97/105, 92%; EEA: 19/19, 100%). One patient (n=1/115, 1%) tested positively for COVID-19 pre-operatively, requiring a delay of operation until the infection was confirmed as resolved. Asides from transient diabetes insipidus; no other complications were reported for this case. All theatre staff wore at least level 2 PPE. Adaptations to surgical techniques included minimising drilling, draping modifications, and using nasal iodine wash. At 30 days postoperatively, there was no evidence of COVID infection (symptoms or on formal testing) in our cohort, and no mortality. Conclusions Preoperative screening protocols and operative modifications have facilitated endonasal neurosurgery during the COVID-19 pandemic, with Pituitary Society guidelines followed for the majority of these operations. There was no evidence of COVID infection in our cohort, and no mortality, supporting the use of risk mitigation strategies to continue endonasal neurosurgery in subsequent pandemic waves

CSF Rhinorrhoea After Endonasal Intervention to the Skull Base (CRANIAL) - Part 1:Multicenter Pilot Study

Background CRANIAL (CSF Rhinorrhoea After Endonasal Intervention to the Skull Base) is a prospective, multicentre observational study seeking to determine: (1) the scope of skull base repair methods used; and (2) corresponding rates of postoperative CSF rhinorrhoea in endonasal transsphenoidal (TSA) expanded endonasal approaches (EEA) for skull base tumours. We sought to pilot the project - assessing the feasibility and acceptability by gathering preliminary data. Methods A prospective, observational cohort pilot study was carried out at twelve tertiary UK neurosurgical units. Feedback regarding project positives and challenges were qualitatively analysed. Results 187 cases were included, 159 TSA (85%) and 28 EEA (15%). The most common pathologies included: pituitary adenomas (n=141/187), craniopharyngiomas (n=13/187) and skull-base meningiomas (n=4/187). The most common skull base repair techniques used were tissue glues (n=132/187, most commonly Tisseel®), grafts (n=94/187, most commonly fat autograft or Spongostan™) and vascularised flaps (n=51/187, most commonly nasoseptal). These repairs were most frequently supported by nasal packs (n=125/187) and lumbar drains (n=22/187). Biochemically-confirmed CSF rhinorrhoea occurred in 6/159 (3.8%) TSA and 2/28 (7.1%) EEA. Four TSA (3%) and two EEA (7%) cases required operative management for CSF rhinorrhoea (CSF diversion or direct repair). Qualitative feedback was largely positive (themes included: user-friendly and efficient data collection, strong support from senior team members) demonstrating acceptability. Conclusions Our pilot experience highlights the acceptability and feasibility of CRANIAL. There is a precedent for multicentre dissemination of this project, in order to establish a benchmark of contemporary skull base neurosurgery practice, particularly with respect to EEA cases. Keywords Cerebrospinal fluid rhinorrhoeaCSFCerebrospinal fluid leakskull base surgeryendoscopic endonasalEE

ICAR: endoscopic skull‐base surgery

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