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Nocardia cyriacigeorgica has gradually become a common pathogen in clinical microbial infections. Identification of Nocardia at the species level is essential to assess the susceptibility and pathogenicity of antimicrobials. However, there is no suitable method for rapid and accurate laboratory detection of N. cyriacigeorgica. In this study, we combined PCR amplification with the CRISPR-Cas12a system to establish a novel detection platform, named CRISPR-PCR, and applied it to the detection of N. cyriacigeorgica in clinical samples. The Cas12a protein exhibited collateral cleavage activity following CRISPR RNA binding to specific targets, then indiscriminately cleaved nearby single-stranded DNA, and this was evaluated for diagnostic nucleic acid detection by measuring the fluorescence signal using a fluorescence reader. The assay takes only 2 h, including DNA extraction for 20 min, nucleic acid pre-amplification for 70 min, and fluorescence detection for 20 min. The limit of detection for N. cyriacigeorgica was 10-3 ng and the specificity was 100%. Thus, the N. cyriacigeorgica CRISPR-PCR assay is a rapid and specific method for detecting N. cyriacigeorgica, and the CRISPR-PCR fluorescence detection platform has great potential for detection of other pathogens.

The timing of high lake-level stands during the Late Pleistocene in western China remains controversial. Here we report new results from Megalake Tengger based on a study of palaeo-shorelines and a drill core from Baijian Lake in the northwestern Tengger Desert. Multiple dating methods, based on luminescence signals (quartz optically stimulated luminescence, K-feldspar post infrared-infrared stimulated luminescence) and electron spin resonance signals of quartz, were used to date beach sands from palaeo-shoreline profiles at altitudes of similar to 1310 m (+20 m above lake level), similar to 1320 m (+30 m) and similar to 1350 m (+60 m), and from the top 20 m of sandy sediments from the drill core obtained from the modern beach of Baijian Lake. The dating results show that high lake-level stands associated with the previously reported Megalake Tengger (similar to 1310-1320 m) occurred during the late Early to Middle Pleistocene, which is much earlier than previously reported. In addition, no geomorphological evidence of shorelines and sedimentary evidence from the drill core profile were found to support the previously reported Late Pleistocene lake levels. Our results indicate that the exact age of the previously reported 'high lake level event' in a large part of northwestern China during the Late Pleistocene needs to be re-evaluated. Copyright (c) 2020 John Wiley & Sons, Ltd.

Due to the exceptional thermal conductivity and material hardness, CVD diamonds have been ideal materials for cutting tools; however, the specific properties of CVD diamonds vary with the grain size. An experimental study was carried out on chemical vapor deposition (CVD) diamonds with varying grain sizes in laser processing. This study aims to analyze the behavior of polycrystalline CVD diamonds under different thermal processing based on its thermal conductivity model. The pit formed under a single laser pulse on the material with a small grain size is shallow and tiny, because of its small thermal conductivity, a value calculated using the established model. The results show that for laser-machined surface, the material with a small grain size can obtain a better machined surface but a small material-removal depth; conversely, material with a large grain size provided opposite experimental results. Additionally, reasonable laser parameters achieved the desired material-removal depth of up to or even exceeding 180 μm and surface roughness Sa as low as 0.2 μm. Overall, both the grain sizes of polycrystalline CVD diamonds and laser parameters affect the machining result. However, there are considerable obstacles in simultaneously achieving a good surface and massive material removal. Hence, a tradeoff between the two aspects is essential in an actual machining process, and this study provides some useful guidance to practitioners and academicians.

Additional file 1: Figure S1. [Heat map of the Pearson correlation of gene expression between samples for RNA-seq data]. Figure S2. [KEGG pathway analysis of DEGs for N. farcinica and A549 cells]. Figure S3. [KEGG pathway analysis]. Figure S4. [Validation of RNA-seq via qRT–PCR]. Figure S5. [Volcano plot obtained from DESeq2 analysis of DEGs from Nocardia farcinica]. Figure S6. [KEGG pathway analysis of Nocardia at 3 and 6 hpi]. Figure S7. [Analysis of the N. farcinica mutant strains]. Figure S8. [Volcano plot obtained from DESeq2 analysis of DEGs from A549 cells]. Figure S9. [The colony status of the Nocardia strains on the blood plate]. Figure S10. [Analysis of inflammatory factors in serum and brain]. Figure S11. [Original gel images with indicated figures].

Additional file 1: Fig. S1. Nonsignificant difference in MEF2C-AS1 expression between lesion tissues and normal tissues among 21 cancers by the GEPIA database. Every dot represents the expression level for a tissue sample. Box plot in red or gray represents the distribution of expression level. Expression level is presented in log2(TPM+1) scale. TPM, Transcripts Per Million. ns p > 0.05. Fig. S2. Comparisons of MEF2C-AS1 methylation between lesion tissues and normal tissues among 21 cancers by the UCSC Xena database. Violin plot in blue or orange represents the distribution of methylation level. * p < 0.05, ns p > 0.05. Fig. S3. The amplified sequence of MEF2C-AS1 was used for the methylation measurement by the MassARRAY method. CpG sites in capital letters were measured, and CpG_1 and CpG_25 correspond to cg10571951 and cg12621171, respectively. CpG sites highlighted in yellow were successfully measured, and those in gray were filtered for methylation analysis. Table S1. The putative predicted target miRNAs and mRNAs of MEF2C-AS1 in CRC.