Plasma Mutagenesis of Haematococcus lacustris and Optimization of Culture Conditions for High-yield Astaxanthin Algae Strains

To further enhance the industrial utilization value of Haematococcus lacustris, the plasma mutagenesis of Haematococcus lacustris was carried out by an atmospheric and room temperature plasma (ARTP) mutagenesis equipment. The optimum input power and mutagenesis time for plasma mutagenesis were determined with lethal rate of algal cells as the index. After mutagenesis, high-yield astaxanthin mutant algae strains were obtained through primary screening of solid plate culture and secondary screening of liquid culture. Then, the culture conditions of high yield algal plants at vegetative growth stage were optimized by single-factor and orthogonal experiment with algae cell density as the index, and the suitable high light conditions for astaxanthin accumulation during astaxanthin induction stage were selected. The genetic stability of the high yielding mutant algae strains was observed after multiple subcultures under the optimized culture conditions. The results showed that the optimum conditions for plasma mutagenesis of Haematococcus lacustris were 240 W for 150 s or 400 W for 120 s. 11 Mutant alga strains with fast growth and high astaxanthin yield were obtained through primary screening and rescreening, wherein the strain HP3 grew fastest and had the highest astaxanthin yield. After culture, its cell density and astaxanthin yield were increased by 25.5% and 61.6% respectively compared with the original strain. After two-stage optimization, the cell density and astaxanthin yield of HP3 increased by 14.3% and 19.3% respectively, reaching 7.2×105 cell/mL and 31.264 mg/L. HP3 showed good growth and stable heredity. Its cell density and astaxanthin yield were similar to those of primary culture. The results have practical significance for the breeding of industrial algal strains producing astaxanthin from Haematococcus lacustris

Mutations in KDSR Cause Recessive Progressive Symmetric Erythrokeratoderma

Supplemental Data Supplemental Data include five figures and three tables and can be found with this article online at http://dx.doi.org/10.1016/j.ajhg.2017.05.003. Supplemental Data Document S1. Figures S1–S5 and Tables S1–S3 Download Document S2. Article plus Supplemental Data Download Web Resources 1000 Genomes, http://www.internationalgenome.org/ ANNOVAR, http://annovar.openbioinformatics.org/en/latest/ BWA-MEM, http://bio-bwa.sourceforge.net/index.shtml Database of Genomic Variants, http://dgv.tcag.ca/dgv/app/home dbSNP, https://www.ncbi.nlm.nih.gov/projects/SNP/ Exome Aggregation Consortium (ExAC) Browser, http://exac.broadinstitute.org/ ExonPrimer, https://ihg.helmholtz-muenchen.de/ihg/ExonPrimer.html GenBank, https://www.ncbi.nlm.nih.gov/genbank/ Genome Analysis Toolkit (GATK), https://software.broadinstitute.org/gatk/ Integrative Genomics Viewer (IGV), http://software.broadinstitute.org/software/igv/ OMIM, https://www.omim.org/ SNPmasker, http://bioinfo.ebc.ee/snpmasker/ UCSC Genome Browser, https://genome.ucsc.edu/index.html Variant Effect Predictor, http://useast.ensembl.org/info/docs/tools/vep/index.html The discovery of new genetic determinants of inherited skin disorders has been instrumental to the understanding of epidermal function, differentiation, and renewal. Here, we show that mutations in KDSR (3-ketodihydrosphingosine reductase), encoding an enzyme in the ceramide synthesis pathway, lead to a previously undescribed recessive Mendelian disorder in the progressive symmetric erythrokeratoderma spectrum. This disorder is characterized by severe lesions of thick scaly skin on the face and genitals and thickened, red, and scaly skin on the hands and feet. Although exome sequencing revealed several of the KDSR mutations, we employed genome sequencing to discover a pathogenic 346 kb inversion in multiple probands, and cDNA sequencing and a splicing assay established that two mutations, including a recurrent silent third base change, cause exon skipping. Immunohistochemistry and yeast complementation studies demonstrated that the mutations cause defects in KDSR function. Systemic isotretinoin therapy has achieved nearly complete resolution in the two probands in whom it has been applied, consistent with the effects of retinoic acid on alternative pathways for ceramide generation

Quantum critical point in SmO1−xFxFeAs and oxygen vacancy induced by high fluorine dopant

The local lattice and electronic structure of the high-T(c) superconductor SmO(1-x)F(x)FeAs as a function of F-doping have been investigated by Sm L(3)-edge X-ray absorption near-edge structure and multiple-scattering calculations. Experiments performed at the L(3)-edge show that the white line (WL) is very sensitive to F-doping. In the under-doped region (x ≤ 0.12) the WL intensity increases with doping and then it suddenly starts decreasing at x = 0.15. Meanwhile, the trend of the WL linewidth versus F-doping levels is just contrary to that of the intensity. The phenomenon is almost coincident with the quantum critical point occurring in SmO(1-x)F(x)FeAs at x ≃ 0.14. In the under-doped region the increase of the intensity is related to the localization of Sm-5d states, while theoretical calculations show that both the decreasing intensity and the consequent broadening of linewidth at high F-doping are associated with the content and distribution of oxygen vacancies

Efficient spin–orbit torque switching in perpendicularly magnetized CoFeB facilitated by Fe2O3 underlayer

Spin–orbit torque (SOT) is recognized as an effective way to manipulate magnetization in spintronic devices. For the low-power consumption and high-endurance requirements of future computer architectures, reducing the critical SOT switching current density and improving SOT efficiency are crucial, especially in the perpendicularly magnetized structures. Here, we have conducted a comprehensive study on improving the SOT efficiency of the Ta/CoFeB structure with a perpendicular magnetic anisotropy by inserting an oxide insulating layer Fe2O3 as the bottom layer. We found that only a 1–5 nm thickness of Fe2O3 significantly reduces the SOT critical switching current by 70% and enhances the spin Hall angle of Ta. The spin Hall angle increases from 0.078 for pure Ta/CoFeB to 0.13 for Fe2O3/Ta/CoFeB, and both types of spin–orbit torques, damping-like and field-like torques, are significantly enhanced. It is suggested that the atomic diffusion of O from the Fe2O3 underlayer leads to the partial oxidization of the Ta layer as well as the Ta/CoFeB interfaces, accounting for the observed enhanced SOT efficiency. Our results provide a reliable method to improve the SOT performance in perpendicularly magnetized structures by inserting the oxide underlayer using magnetron sputtering, in favor of its potential real-world application in spintronic devices

Thoracic myelopathy caused by ossification of ligamentum flavum of which fluorosis as an etiology factor

PURPOSE: To evaluate the clinical feature, operative method and prognosis of thoracic ossification of ligamentum flavum caused by skeletal fluorosis. METHODS: All the patients with thoracic OLF, who underwent surgical management in the authors' hospital from 1993–2003, were retrospectively studied. The diagnosis of skeletal fluorosis was made by the epidemic history, clinical symptoms, radiographic findings, and urinalysis. En bloc laminectomy decompression of the involved thoracic levels was performed in all cases. Cervical open door decompression or lumbar laminectomy decompression was performed if relevant stenosis existed. The neurological statuses were evaluated with the Japanese Orthopaedic Association (JOA) scoring system preoperatively and at the end point of follow up. Also, the recovery rate was calculated. RESULTS: 23 cases have been enrolled in this study. Imaging study findings showed all the cases have ossification of ligamentum flavum together with ossification of many other ligaments and interosseous membranes, i.e. interosseous membranes of the forearm in 18 of 23 (78.3%), of the leg in 14 of 23 (60.1%) and of the ribs in 11 of 23 (47.8%). Urinalysis showed markedly increased urinary fluoride in 14 of 23 patients (60.9%). All the patients were followed up from 12 months to 9 years and 3 months, with an average of 4 years and 5 months. The JOA score increased significantly at the end of follow up (P = 0.0001). The recovery rate was 51.83 ± 32.36%. Multiple regression analysis revealed that the preoperative JOA score was an important predictor of surgical outcome (p = 0.0022, r = 0.60628). ANOVA analysis showed that patients with acute onset or too long duration had worse surgical result (P = 0.0003). CONCLUSION: Fluorosis can cause ossification of thoracic ligamentum flavum, as well as other ligaments. En bloc laminectomy decompression was an effective method. Preoperative JOA score was the most important predictor of surgical outcome. Patients with acute onset or too long duration had worse surgical outcome

Broad and strong memory CD4(+)and CD8(+)T cells induced by SARS-CoV-2 in UK convalescent individuals following COVID-19

The development of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines and therapeutics will depend on understanding viral immunity. We studied T cell memory in 42 patients following recovery from COVID-19 (28 with mild disease and 14 with severe disease) and 16 unexposed donors, using interferon-γ-based assays with peptides spanning SARS-CoV-2 except ORF1. The breadth and magnitude of T cell responses were significantly higher in severe as compared with mild cases. Total and spike-specific T cell responses correlated with spike-specific antibody responses. We identified 41 peptides containing CD4+ and/or CD8+ epitopes, including six immunodominant regions. Six optimized CD8+ epitopes were defined, with peptide–MHC pentamer-positive cells displaying the central and effector memory phenotype. In mild cases, higher proportions of SARS-CoV-2-specific CD8+ T cells were observed. The identification of T cell responses associated with milder disease will support an understanding of protective immunity and highlights the potential of including non-spike proteins within future COVID-19 vaccine design