42 research outputs found
A method for increasing the supersolvus critical strain for recrystallization in single-crystal superalloys
Recrystallization, possibly triggered during heat treatments by plastic strains of only 1–2%, is highly deleterious to Ni-based single-crystal superalloys. Herein, we successfully recover plastic deformation and enhance the supersolvus critical strain for recrystallization by ramping the annealing temperature slowly from 1100 °C to γ′-solvus point. This preempts recrystallization during the subsequent supersolvus solutionizing treatment. The proposed method is validated in single-crystals compressed to 5.9% plastic strain at room temperature. After supersolvus solutionizing, an almost dislocation-free single-crystal with uniformly distributed γ′-precipitates is obtained. The proposed method offers a practical means to bring down the overall expenses of single-crystal turbine blades
Identification of paternal germline mosaicism by MicroSeq and targeted next‐generation sequencing
Abstract Background Prezygotic de novo mutations may be inherited from parents with germline mosaicism and are often overlooked when the resulting phenotype affects only one child. We aimed to identify paternal germline mosaicism in an index family and provide a strategy to determine germline mosaicism.‘ Methods Whole‐exome sequencing was performed on an Alport syndrome‐affected child. Variants were validated using Sanger sequencing in the pedigree analysis. An apparent de novo mutation was tested by next‐generation sequencing (NGS) following chromosome microdissection of the mutant region (MicroSeq) to clarify its homologous chromosome source. Mosaic mutation in sperm samples was detected using targeted next‐generation sequencing (TNGS). Self‐prepared mosaic DNA samples of the 3% and 0.1% mutant fractions were used to evaluate the TNGS detection sensitivity. Results Two novel heterozygous variants, maternally inherited c.1322delT (p.Ile441Thrfs*17) and the de novo mutation c.2939T>A (p.Leu980Ter), in the COL4A3 gene were discovered in the propositus. MicroSeq identified c.2939T>A in the paternal chromosome, which was in trans with c.1322delT. The frequency of c.2937A was 2.65% in the father's sperm sample. We also showed that a 500X depth coverage may detect a mosaic mutation with an allele frequency as low as 2%–3% using TNGS. Conclusion MicroSeq is a valuable tool to identify the allele source of de novo mutations in a single patient. TNGS can be used to assess the mosaic ratios of known sites. We provided a systematic algorithm to detect germinal mosaicism in a single patient. This algorithm may have implications for genetic and reproductive counseling on germline mosaicism
Decarbonising the iron and steel sector for a 2 °C target using inherent waste streams
International audienceThe decarbonisation of the iron and steel industry, contributing approximately 8% of current global anthropogenic CO2 emissions, is challenged by the persistently growing global steel demand and limitations of techno-economically feasible options for low-carbon steelmaking. Here we explore the inherent potential of recovering energy and re-using materials from waste streams, high-temperature slag, and re-investing the revenues for carbon capture and storage. In a pathway based on energy recovery and resource recycling of glassy blast furnace slag and crystalline steel slag, we show that a reduction of 28.5 ± 5.7% CO2 emissions to the sectoral 2 °C target requirements in the iron and steel industry could be realized in 2050 under strong decarbonization policy consistent with low warming targets. The technological schemes applied to engineer this high-potential pathway could generate a revenue of US40 ± 18 billion globally in 2035 and 2050, respectively. If this revenue is used for carbon capture and storage implementation, equivalent CO2 emission to the 2 °C sectoral target requirements is expected to be reduced before 2050, without any external investments
Sun-Angle Effects on Remote-Sensing Phenology Observed and Modelled Using Himawari-8
Satellite remote sensing of vegetation at regional to global scales is undertaken at considerable variations in solar zenith angle (SZA) across space and time, yet the extent to which these SZA variations matter for the retrieval of phenology remains largely unknown. Here we examined the effect of seasonal and spatial variations in SZA on retrieving vegetation phenology from time series of the Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) across a study area in southeastern Australia encompassing forest, woodland, and grassland sites. The vegetation indices (VI) data span two years and are from the Advanced Himawari Imager (AHI), which is onboard the Japanese Himawari-8 geostationary satellite. The semi-empirical RossThick-LiSparse-Reciprocal (RTLSR) bidirectional reflectance distribution function (BRDF) model was inverted for each spectral band on a daily basis using 10-minute reflectances acquired by H-8 AHI at different sun-view geometries for each site. The inverted RTLSR model was then used to forward calculate surface reflectance at three constant SZAs (20°, 40°, 60°) and one seasonally varying SZA (local solar noon), all normalised to nadir view. Time series of NDVI and EVI adjusted to different SZAs at nadir view were then computed, from which phenological metrics such as start and end of growing season were retrieved. Results showed that NDVI sensitivity to SZA was on average nearly five times greater than EVI sensitivity. VI sensitivity to SZA also varied among sites (biome types) and phenological stages, with NDVI sensitivity being higher during the minimum greenness period than during the peak greenness period. Seasonal SZA variations altered the temporal profiles of both NDVI and EVI, with more pronounced differences in magnitude among NDVI time series normalised to different SZAs. When using VI time series that allowed SZA to vary at local solar noon, the uncertainties in estimating start, peak, end, and length of growing season introduced by local solar noon varying SZA VI time series, were 7.5, 3.7, 6.5, and 11.3 days for NDVI, and 10.4, 11.9, 6.5, and 8.4 days for EVI respectively, compared to VI time series normalised to a constant SZA. Furthermore, the stronger SZA dependency of NDVI compared with EVI, resulted in up to two times higher uncertainty in estimating annual integrated VI, a commonly used remote-sensing proxy for vegetation productivity. Since commonly used satellite products are not generally normalised to a constant sun-angle across space and time, future studies to assess the sun-angle effects on satellite applications in agriculture, ecology, environment, and carbon science are urgently needed. Measurements taken by new-generation geostationary (GEO) satellites offer an important opportunity to refine this assessment at finer temporal scales. In addition, studies are needed to evaluate the suitability of different BRDF models for normalising sun-angle across a broad spectrum of vegetation structure, phenological stages and geographic locations. Only through continuous investigations on how sun-angle variations affect spatiotemporal vegetation dynamics and what is the best strategy to deal with it, can we achieve a more quantitative remote sensing of true signals of vegetation change across the entire globe and through time
Generation of induced pluripotent stem cells (iPSCs) from a retinoblastoma patient carrying a c.2663G>A mutation in RB1 gene
Skin fibroblasts were obtained from a male patient diagnosed with retinoblastoma (RB) carrying a c.2663G>A mutation in the 25 exon of RB1 gene. RB-iPS cells was generated via delivered four reprogramming factors (OCT4, SOX2, NANOG and LIN28) into these skin fibroblasts. The RB-iPS cells retained the RB1 heterozygous mutation resulted in a truncated RB1 mRNA. Characteristic tests proved that the iPSC line presented typical markers of pluripotency and had the capability to form the three germ layers in vitro
Nonlinear optical microscopy for in vivo imaging microvasculature and blood flow
We demonstrate in vivo microvasculature and blood flow imaging based on two-photon excited autofluorescence of blood plasma and NADH in zebrafish. The blood flow images enable counting circulating leukocyte for detecting acute sterile inflammation. © 2014 OS
Theoretical Investigation of All Optical Switching by Intersystem Crossing
The dynamics of spin flips induced by the femtosecond laser are theoretically investigated in this article. The spin flips in this scenario are attributed to the intersystem crossing (ISC) described within the frame of the Rabi model. This new explanation is a step attempting to explain the mechanism of the all-optical magnetic orientation switching in the perspective of the conservation of the angular momentum and breaks of the selection rule, which is ignored in the Raman scattering related explanations. The final spin states discussed herein are closely related to the intensity of the incident laser and the ISC decay rate. The quantitative analysis of the relation between decay rate, temperature and the intensity of the laser is discussed