Construction of an economical xylose-utilizing Saccharomyces cerevisiae and its ethanol fermentation.

Traditional industrial Saccharomyces cerevisiae could not metabolize xylose due to the lack of a specific enzyme system for the reaction from xylose to xylulose. This study aims to metabolically remould industrial S. cerevisiae for the purpose of utilizing both glucose and xylose with high efficiency. Heterologous gene xylA from Piromyces and homologous genes related to xylose utilization were selected to construct expression cassettes and integrated into genome. The engineered strain was domesticated with industrial material under optimizing conditions subsequently to further improve xylose utilization rates. The resulting S. cerevisiae strain ABX0928-0630 exhibits a rapid growth rate and possesses near 100% xylose utilization efficiency to produce ethanol with industrial material. Pilot-scale fermentation indicated the predominant feature of ABX0928-0630 for industrial application, with ethanol yield of 0.48 g/g sugars after 48 hours and volumetric xylose consumption rate of 0.87 g/l/h during the first 24 hours. Transcriptome analysis during the modification and domestication process revealed a significant increase in the expression level of pathways associated with sugar metabolism and sugar sensing. Meanwhile, genes related to glycerol lipid metabolism exhibited a pattern of initial increase followed by a subsequent decrease, providing a valuable reference for the construction of efficient xylose-fermenting strains.

Rapid imaging and product screening with low-cost line-field Fourier domain optical coherence tomography.

Fourier domain optical coherence tomography (FD-OCT) is a well-established imaging technique that provides high-resolution internal structure images of an object at a fast speed. Modern FD-OCT systems typically operate at speeds of 40,000-100,000 A-scans/s, but are priced at least tens of thousands of pounds. In this study, we demonstrate a line-field FD-OCT (LF-FD-OCT) system that achieves an OCT imaging speed of 100,000 A-scan/s at a hardware cost of thousands of pounds. We demonstrate the potential of LF-FD-OCT for biomedical and industrial imaging applications such as corneas, 3D printed electronics, and printed circuit boards.

Global, regional and national burden of pancreatic cancer, 1990 to 2017: Results from the Global Burden of Disease Study 2017.

BACKGROUND: The global burden of pancreatic cancer (PCa) continues to grow. Detailed data on PCa epidemiology are essential for policy-making and appropriate healthcare resource allocation. METHODS: Estimates of incidence, death and disability-adjusted life years (DALYs) of PCa from 1990 to 2017 were collected from the Global Burden of Disease Study 2017. Decomposition analysis was conducted to detect the contributing factors related to PCa incidence variation. The estimated annual percentage change (EAPC) was calculated to quantify the PCa epidemiology trends over a specified interval. RESULTS: Globally, the incidence of PCa cases increased by 129.1% to 447 664 664 (95% uncertainty interval (UI) 438 597-456 295), death increased by 125.2% to 441 082 082 (95% UI 448 960-432 833), and DALYs increased by 107.3% to 9 080 004 (95% UI 8 894 128-9 256 346) between 1990 and 2017. Relatively higher sociodemographic index (SDI) regions were observed with greater incidences, more deaths and a greater number of DALYs of PCa, but relatively lower SDI regions experienced a sharply increasing trend in these measures. Decomposition analysis indicated that the global increase in PCa incidence was driven by the aging population from 2007 to 2017, especially in higher SDI regions. In addition, a significant negative correlation was found between EAPC and ASIR (in 1990) (r = -0.56, P < 0.001). CONCLUSIONS: PCa remains a major public health burden globally. The unfavorable trend in PCa suggesting that further study for prevention should be conducted to forestall the increase in pancreatic cancer.