20 research outputs found
Simultaneous production of triacylglycerol and high-value carotenoids by the astaxanthin-producing oleaginous green microalga Chlorella zofingiensis
No full textThe production of lipids and astaxanthin, a high-value carotenoid, by Chlorella zofingiensis was investigated under different culture conditions. Comparative analysis revealed a good correlation between triacylglycerol (TAG) and astaxanthin accumulation in C. zofingiensis. Stress conditions promoted cell size and weight and induced the accumulation of neutral lipids, especially TAG and astaxanthin, with a concomitant decrease in membrane lipids. The highest contents of TAG and astaxanthin achieved were 387 and 4.89 mg g(-1) dry weight, respectively. A semi-continuous culture strategy was developed to optimize the TAG and astaxanthin productivities, which reached 297 and 3.3 mg L-1 day(-1), respectively. Additionally, astaxanthin accumulation was enhanced by inhibiting de novo fatty acid biosynthesis. In summary, our study represents a pioneering work of utilizing Chlorella for the integrated production of lipids and high-value products and C. zofingiensis has great potential to be a promising production strain and serve as an emerging oleaginous model alga. (C) 2016 Elsevier Ltd. All rights reserved.National Natural Science Foundation of China [31571807]; start-up grant from National Youth Thousand Talents Program; 985 Project of Peking UniversitySCI(E)[email protected]
Study on the construction method and deformation control technology of small interval cross tunnel in water-enriched soil layers
No full textBio-mitigation of carbon dioxide using microalgal systems: Advances and perspectives
No full textCarbon sequestration is an important strategy in combating rising carbon dioxide concentration in the atmosphere. Differing from carbon emission reduction, carbon sequestration offers the possibilities of reducing or avoiding CO2 emission if CO2 is to be captured from large stationary sources and utilization of the captured CO2 for production of chemical and energy. Biological sequestration or bio-mitigation of carbons through microalgal systems, despite in its early stage, represents a promising and sustainable alternative to current carbon mitigation methods. Microalgae consist of a group of highly diverse and fast-growing microorganisms, capable of photoautotrophy, heterotrophy, and mixotrophy. They can be cultivated on non-fertile land with unit CO2 fixation capacity 10-50 times higher than terrestrial plants. Production of food, feed, fine chemicals, and biofuels from microalgal biomass could further enhance the benefits of microalgae-based CO2 fixation. This present review is aimed to gain understanding how microalgae assimilate different forms of carbons and provide a comprehensive overview of the current advances in utilizing microalgae for CO2 fixation, with focus on strain screening and improvement, mass cultivation practice, and effects of environmental and nutritional factors on CO2 fixation performance. Economic viability, challenges and perspectives of microalgae-mediated CO2 bio-mitigation are also discussed.National Natural Science Foundation of China [51668044, 31571807]; Key Research Development Program of the Jiangxi Province of China [20161BBH80029]; Key Science and Technology Research Program of Department of Education of the Jiangxi Province of China [150029]; Singapore-Peking University Research Centre for a sustainable Low-Carbon Future; China Postdoctoral Science Foundation [2016M591188]; National Young Thousand Talents Program of ChinaSCI(E)REVIEW1163-11757
Four-wheel Steering Control Algorithm of Long Wheelbase Vehicles
No full textLong wheelbase design of vehicle can effectively increase the standing area without increasing the body length, thus increasing the passenger capacity. Today, with the development of urbanization, the long wheelbase vehicle design has become a trend, but this poses new challenges to the low-speed trafficability and high-speed stability of vehicles. This paper takes the long wheelbase commercial vehicle as the research object. Based on the vehicle dynamics and suspension design theory, the author first designed key parameters of long wheelbase vehicle and built an 18 degrees of freedom (DOF) dynamics simulation model for the vehicle; then designed the four-wheel steering (4WS) control algorithm according to the design parameters of the vehicle, for achieving the control target that the side slip angle tends to zero; and finally researched the influence of front-wheel steering (FWS) control and four-wheel steering control on the dynamic performance of the vehicle under the steady-state circumferential conditions with different turning radiuses and steering wheel angle pulse conditions with different speeds. The simulation results show that, under the steady-state circumferential turning condition with a low-speed turning radius of R15, the four-wheel steering design reduces the passing space from 4.6 m to 3.9 m, effectively improving the tracking ability of the front and rear axles of the vehicle and enhancing the trafficability and safety of the vehicle, and under the pulse condition with a maximum speed of 100 km/h, reduces the peak lateral acceleration from 4 m/s2 to 1.5 m/s2 and the peak yaw rate from 11°/s to 3°/s. Therefore, under high-speed steering wheel angle pulse conditions, the four-wheel steering design can effectively reduce the dynamic indicators of the vehicle, such as side slip angle, lateral acceleration and yaw rate, and improve the safety, stability and comfort of the vehicle at high speed
The N-terminal doublestranded RNA binding domains of Arabidopsis HYPONASTIC LEAVES1 are sufficient for pre-microRNA processing
No full textArabidopsis thaliana HYPONASTIC LEAVES1 (HYL1) is a microRNA (miRNA) biogenesis protein that contains two N-terminal double-stranded RNA binding domains (dsRBDs), a putative nuclear localization site (NLS), and a putative protein–protein interaction domain. The interaction of HYL1 with DICER-LIKE1 is important for the efficient and precise processing of miRNA primary transcripts in plantmiRNAbiogenesis. Todefine the roles of the variousdomainsofHYL1 inmiRNAprocessing and the miRNA-directed phenotype, we transferred a series of HYL1 deletion constructs into hyl1 null mutants. The N-terminal region containing dsRBD1anddsRBD2 completely rescued themutant phenotype of hyl1, triggering the accumulation ofmiR166 and miR160 and resulting in reduced mRNA levels of the targeted genes. In vivo biochemical analysis of the HYL1-containing complexes from the transgenic plants revealed that the N-terminal dsRBDs of HYL1 were sufficient for processing miRNA precursors and thegeneration ofmaturemiRNA. Transient and stable expression analysis demonstrated that the putativeNLS domainwas indeed the nuclear localization signal, whereas theN-terminal region containing the dsRBDswas not restricted to the nucleus. We suggest that the N-terminal dsRBDs fulfill the function of the whole HYL1 and thus play an essential role in miRNA processing and miRNA-directed silencing of targeted genes
Local gene delivery via endovascular stents coated with dodecylated chitosan–plasmid DNA nanoparticles
No full textRoadmap on soft robotics: multifunctionality, adaptability and growth without borders
No full textSoft robotics aims at creating systems with improved performance of movement and adaptability in unknown, challenging, environments and with higher level of safety during interactions with humans. This Roadmap on Soft Robotics covers selected aspects for the design of soft robots significantly linked to the area of multifunctional materials, as these are considered a fundamental component in the design of soft robots for an improvement of their peculiar abilities, such as morphing, adaptivity and growth. The roadmap includes different approaches for components and systems design, bioinspired materials, methodologies for building soft robots, strategies for the implementation and control of their functionalities and behaviour, and examples of soft-bodied systems showing abilities across different environments. For each covered topic, the author(s) describe the current status and research directions, current and future challenges, and perspective advances in science and technology to meet the challenges
