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Abstract A 2-day-old neonate presented with seizures, multiple intracranial hemorrhages, and bilateral congenital cataracts. Targeted next-generation sequencing of the collagen type IV alpha 1 chain (COL4A1) gene revealed a heterozygous de novo missense variant (NM_001845.6:c.2291G>A/p.Gly764Asp). This missense variant adds to the compendium of COL4A1 variants and is associated with a COL4A1-related disorder.

We report a 14-year-old girl with a heterozygous p. Gln403Arg variant in the MYRF gene, who had five episodes of encephalopathy. She experienced reduced consciousness, numbness in the arm, and impaired verbal communication from day 4 of SARS-CoV-2 infection. Magnetic resonance imaging of her head showed reduced water diffusion in the corpus callosum and deep white matter. These features were similar to those seen in her previous episodes of encephalopathy. She was treated with methylprednisolone pulse therapy and recovered completely within a week.

Surfactin, which is an anionic bio-surfactant, can be effective for enhanced oil recovery because it decreases interfacial tension between oil and water. However, it forms precipitation by binding with divalent cations. This study examined the countermeasure to prevent surfactin from forming precipitation for applying it to enhanced oil recovery. Alcohols, chelating agents, a cationic surfactant and an ion capturing substance were selected as the candidates for inhibiting surfactin from forming precipitation. Citric acid and trisodium citrate were selected as promising candidates through the measurements of turbidity of the mixture of the candidate, surfactin and calcium ions. Those chemicals also had a function as a co-surfactant for surfactin. However, the permeability of the Berea sandstone core into which the solution containing surfactin and trisodium citrate was injected was decreased significantly, whereas citric acid could be injected into the core without significant permeability reduction. Citric acid was therefore selected as the best inhibitor and subjected to the core flooding experiments. High enhancement of oil recovery of 9.4% (vs. original oil in place (OOIP)) was obtained and pressure drop was not increased during the injection of surfactin and citric acid. Those results suggest that citric acid has a dual role as the binding inhibitor and co-surfactant for surfactin.