Conversion of Na HCO 3 to Na 2 CO 3 with a growth of Arthrospira platensis cells in 660 m 2 raceway ponds with a CO 2 bicarbonation absorber

Summary The weight ratio of Na 2 CO 3 /Na HCO 3 was investigated in order to improve microalgal productivity in large‐scale industrial operations by converting Na HCO 3 to Na 2 CO 3 with a growth of Arthrospira platensis cells in 660 m 2 raceway ponds. Two microalgal cultivation systems with a Na HCO 3 by‐product ( SPBP ) and a CO 2 bicarbonation absorber ( CBAP ) were firstly thoroughly introduced. There was a 13.3% decrease in the initial weight ratio of Na 2 CO 3 /Na HCO 3 resulting in a 25.3% increase in the biomass growth rate with CBAP , compared to that of SPBP . Increased sunlight intensity, solution temperature and pH all resulted in both a higher HCO 3 - absorbance and CO 3 2 -release, thereby increasing the weight ratio of Na 2 CO 3 /Na HCO 3 during the growth of A. platensis . The biomass growth rate was peaked at 39.9 g m −2  day −1 when the weight ratio of Na 2 CO 3 /Na HCO 3 was 3.7. Correspondingly, the cell pigments (chlorophyll a and carotenoid) and trichome size (helix pitch and trichome length) reached to a maximum state of 8.47 mg l −1 , 762 μg l −1 , 57 and 613 μm under the CBAP system.

Lion and spotted hyaena abundance in Dinder National Park, Sudan

The role of levonorgestrel intra‐uterine system in the management of adenomyosis: A systematic review and meta‐analysis of prospective studies

The levonorgestrel intrauterine system (LNG‐IUS) is a long‐acting hormone‐releasing uterine device that has many non‐contraceptive benefits. The study aims to assess the safety and efficacy of LNG‐IUS in the management of adenomyosis. Material and methods We searched the following bibliographic databases: MEDLINE via PubMed, SCOPUS, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE and Google Scholar for the relevant studies which used LNG‐IUS in management of patients with clinically or ultrasonographic diagnosed adenomyosis.The main outcome measures are pain score at the end of follow‐up, bleeding, symptomatic relief, uterine volume (mL), endometrial thickness (mm) and/or hemoglobin level. Results Ten prospective studies (patients n = 551) were included. The overall effect estimates showed that the LNG‐IUS led to significant reductions in pain score after 12 months (standardized mean difference [SMD[ −3.87, 95% confidence interval [CI] −5.51 to −2.23, P  < .001), 24 months (SMD −5.56, 95% CI −9.80 to −1.32, P  = .01) and 36 months of insertion (SMD −3.81, 95% CI −4.27 to −3.36, P  < .001). Similarly, the Pictorial Blood Assessment Chart (PBAC) showed significant reduction up to 36 months after LNG‐IUS insertion (SMD −2.32, 95% CI −2.91 to −1.73, P  < .001). The LNG‐IUS led to significant reductions in the uterine volume 12 months (SMD −.60, 95% CI −0.88 to −.31, P  < .001) and 36 months after insertion (SMD −0.42, 95% CI −0.69 to −0.14, P  = .003). Conclusions LNG‐IUS is a promising and effective option for the management of adenomyosis. Its use effectively reduced the severity of symptoms, uterine volume and endometrial thickness, and improved laboratory outcomes.

The power of social isolation on paediatric emergency visits during COVID‐19 lockdown

The commercially important shoemaker spinefoot, Siganus sutor , connects coral reefs to neighbouring seagrass meadows

Spatial management of fish populations can potentially be optimized by determining the area of influence of a particular species. We performed an acoustic tagging study implemented on Denis Island in the Seychelles to assess the area of influence of the heavily targeted shoemaker spinefoot, Siganus sutor . We investigated whether this species acts as a mobile link between coral patches and seagrass meadows, and whether their movements differed between day and night. The study incorporated an array of 22 acoustic stations deployed within dense coral patches, seagrass meadows and mixed habitats of both seagrass and coral. Fifteen S. sutor carrying internal acoustic tags were monitored from November 2016 until May 2017. Detection patterns revealed them to be diurnal herbivores, with only rare nocturnal movements. Home‐range estimates showed that individuals differed in their spatial range extents and habitats used, covering ~15% of the total shallow subtidal coastline of the island. However, they displayed very small daily movements (<200 m), concentrated mainly around sites within mixed coral and seagrass habitats. An optimal number of detections was recorded when the coral to seagrass area ratio was approximately 1.6:1. This ratio was confirmed through statistical prediction modelling. Identification of such links of commercially important species between networked habitats may help authorities consider incorporating seagrass meadows of the Seychelles into management discussions, which are currently lacking.

Linoleic acid‐derived metabolites constitute the majority of oxylipins in the rat pup brain and stimulate axonal growth in primary rat cortical neuron‐glia co‐cultures in a sex‐dependent manner

In adult rats, omega‐6 linoleic acid (LA, 18:2n‐6) serves as a precursor to oxidized LA metabolites (OXLAMs) known to regulate multiple signaling processes in the brain. However, little is known regarding the levels or role(s) of LA and its metabolites during brain development. To address this gap, fatty acids within various brain lipid pools, and their oxidized metabolites (oxylipins) were quantified in brains from 1‐day‐old male and female pups using gas chromatography and liquid chromatography coupled to tandem mass spectrometry, respectively. Primary neuron‐glia co‐cultures derived from postnatal day 0–1 male and female rat neocortex were exposed to vehicle (0.1% ethanol), LA, the OXLAM 13‐hydroxyoctadecadienoic acid (13‐HODE), or prostaglandin E2 at 10–1000 nM for 48 h to test their effects on neuronal morphology. In both male and female pups, LA accounted for 1–3% of fatty acids detected in brain phospholipids and cholesteryl esters. It was not detected in triacylglycerols, and free fatty acids. Unesterified OXLAMs constituted 47–53% of measured unesterified oxylipins in males and females (vs. ~5–7% reported in adult rat brain). Of these, 13‐HODE was the most abundant, accounting for 30–33% of measured OXLAMs. Brain fatty acid and OXLAM concentrations did not differ between sexes. LA and 13‐HODE significantly increased axonal outgrowth. Separate analyses of cultures derived from male versus female pups revealed that LA at 1, 50, and 1000 nM, significantly increased axonal outgrowth in female but not male cortical neurons, whereas 13‐HODE at 100 nM significantly increased axonal outgrowth in male but not female cortical neurons. prostaglandin E2 did not alter neuronal outgrowth in either sex. This study demonstrates that OXLAMs constitute the majority of unesterified oxylipins in the developing rat brain despite low relative abundance of their LA precursor, and highlights a novel role of LA and 13‐HODE in differentially influencing neuronal morphogenesis in the developing male and female brain.

Changes in Neuroendovascular Procedural Volume During the COVID‐19 Pandemic: An International Multicenter Study

BACKGROUND AND PURPOSE The effect of coronavirus disease 2019 (COVID‐19) pandemic on performance of neuroendovascular procedures has not been quantified. METHODS We performed an audit of performance of neuroendovascular procedures at 18 institutions (seven countries) for two periods; January‐April 2019 and 2020, to identify changes in various core procedures. We divided the region where the hospital was located based on the median value of total number of COVID‐19 cases per 100,00 population‐into high and low prevalent regions. RESULTS Between 2019 and 2020, there was a reduction in number of cerebral angiograms (30.9% reduction), mechanical thrombectomy (8% reduction), carotid artery stent placement for symptomatic (22.7% reduction) and asymptomatic (43.4% reduction) stenoses, intracranial angioplasty and/or stent placement (45% reduction), and endovascular treatment of unruptured intracranial aneurysms (44.6% reduction) and ruptured (22.9% reduction) and unruptured brain arteriovenous malformations (66.4% reduction). There was an increase in the treatment of ruptured intracranial aneurysms (10% increase) and other neuroendovascular procedures (34.9% increase). There was no relationship between procedural volume change and intuitional location in high or low COVID‐19 prevalent regions. The procedural volume reduction was mainly observed in March‐April 2020. CONCLUSIONS We provided an international multicenter view of changes in neuroendovascular practices to better understand the gaps in provision of care and identify individual procedures, which are susceptible to change.

Improved Fluoroscopy and Time Efficiency with Radial Access for Diagnostic Cerebral Angiography

BACKGROUND AND PURPOSE Radial artery catheterization has been newly incorporated into the field of endovascular surgical neuroradiology as a safer and more efficient method for Cerebral angiography as opposed to the femoral artery approach. The objective is to understand the relationship between cerebral angiography procedure times after an operator has converted to a radial first approach. METHODS A retrospective analysis was conducted from January to August of 2019 to compare procedural times for femoral and radial artery approaches. This was conducted by comparing different procedural specifications, such as total procedural time, fluoroscopy time, and amount of contrast used. RESULTS The average age of the 434 patients in the analysis was 63.9 years with a range of 19 and 96 years. One hundred eighty‐three patients (mean fluoroscopy time 7.55, 95% confidence interval 7.03‐8.08) underwent successful diagnostic cerebral angiographies through the radial artery and, 251 patients through the femoral approach. The first 2 months of the radial approach saw an average fluoroscopy time of 11.23 minutes. In the last 2 months of the study, the fluoroscopy time plateaued to an average of 6.73 minutes after 55 cases. Radial artery average procedural time was reduced from 33 to 21 minutes. Angiography utilizing the femoral approach averaged 16 minutes throughout the study period. CONCLUSION Transradial procedural time and fluoroscopy time continued to improve until about 55 cases, but did not reach the peak efficiency of the femoral approach. Further advances in catheter technology are needed to continue to improve radial artery diagnostic cerebral angiography.

Guillain-Barré syndrome presenting with COVID-19 infection

A construction worker in his 30s presented three times in 4 days with progressive upper and then lower limb weakness. On the first two occasions he had no systemic symptoms, but on the third presentation he had fever and cough, starting from day 4 of weakness. Examination identified weakness in all four limbs and areflexia, suggesting a peripheral neuromuscular disorder. Investigations were consistent with Guillain-Barré syndrome and additional COVID-19 (SARS-CoV-2) infection. The patient improved after immunoglobulin treatment. At least four cases of Guillain-Barré syndrome have been reported in the literature with concurrent COVID-19 illness in whom respiratory signs appeared a few days after the onset of neurological signs. With the incubation period for COVID-19 respiratory symptoms believed to be up to 14 days, it is possible that neurological symptoms could develop before respiratory and other symptoms. During the current pandemic, presence of concurrent COVID-19 infection needs to be considered in patients presenting with Guillain-Barré syndrome.

Neuroendovascular clinical trials disruptions due to COVID-19. Potential future challenges and opportunities

To assess the impact of COVID-19 on neurovascular research and deal with the challenges imposed by the pandemic.