396 research outputs found
Acidification of prehydrolysis liquor and spent liquor of neutral sulfite semichemical pulping process
AbstractAcidification has been commercialized for producing kraft lignin from black liquor of kraft pulping process. This work intended to evaluate the effectiveness of acidification in extracting lignocelluloses from the spent liquor of neutral sulfite semichemical pulping (NSSC) process and from prehydrolysis liquor (PHL) of kraft-based dissolving pulp production process. The results showed that the NSSC and PHL spent liquors had some lignin-carbohydrate complexes (LCC), and that the square weighted counts of particles with a chord length of 50–150μm in the spent liquors were significantly increased as pH dropped to 1.5. Interestingly, the acidification reduced the lignosulfonate/lignin content of NSSC and PHL by 13% or 20%, while dropped their oligosugars content by 75% and 38%, respectively. On a dry basis, the precipitates had more carbon, hydrogen and a high heating value of 18–22MJ/kg, but less oxygen, than spent liquors. The precipitates of PHL could be used as fuel
Positive Stability Analysis and Bio-Circuit Design for Nonlinear Biochemical Networks
This paper is concerned with positive stability analysis and bio-circuits design for nonlinear biochemical networks. A fuzzy interpolation approach is employed to approximate nonlinear biochemical networks. Based on the Lyapunov stability theory, sufficient conditions are developed to guarantee the equilibrium points of nonlinear biochemical networks to be positive and asymptotically stable. In addition, a constrained bio-circuits design with positive control input is also considered. It is shown that the conditions can be formulated as a solution to a
convex optimization problem, which can be easily facilitated by using the Matlab LMI control toolbox. Finally, a real biochemical network model is provided to illustrate the effectiveness and validity of the obtained results
Salvianolic acid B Relieves Oxidative Stress in Glucose Absorption and Utilization of Mice Fed High-Sugar Diet
Purpose: To evaluate the influence of Salvianolic acid B (Sal B) on oxidative stress in mice administrated with glucose, sucrose and high-sugar diet.Methods: 40 Kunming mice were divided into four groups of 10. After a fast of 12 h, mice were treated by oral infusion respectively with physiological saline, 20 % glucose, 20 % sucrose, and 20 % glucose + 0.002 % Sal B. Blood glucose and levels of reactive oxygen species (ROS) were determined at 0, 0.5, 1.0, 1.5, and 2.0 h after administration. Another 3 groups of 10 Kunming mice each were fed with normal diet, high-sugar diet (20 % sucrose, HSD) and HSD + 0.002 % Sal B. Four weeks later, the levels of ROS as well as antioxidant enzyme activity were determined.Results: Blood ROS showed the first peak at 0.5 h and a higher peak at 1.5 h after high glucose administration. ROS were mainly produced in liver and pancreas with the utilization of glucose. Sal B administration prevented increase in blood glucose and significantly (p < 0.05) reduced ROS produced in the process of glucose absorption and utilization, especially the latter. Sal B decrease oxidative stress induced by HSD through scavenging ROS associated with increased activity of antioxidant enzymes.Conclusion: This study demonstrates that Sal B can decrease oxidative stress in glucose absorption and utilization in HSD mice. Thus, the findings provide a basis for a potential interventional strategy for protecting against oxidative damage induced by HSD.Keywords: Salvianolic acid B, Blood glucose, Reactive oxygen species, Oxidative stress, Sugar di
Taming Android Fragmentation through Lightweight Crowdsourced Testing
Android fragmentation refers to the overwhelming diversity of Android devices
and OS versions. These lead to the impossibility of testing an app on every
supported device, leaving a number of compatibility bugs scattered in the
community and thereby resulting in poor user experiences. To mitigate this, our
fellow researchers have designed various works to automatically detect such
compatibility issues. However, the current state-of-the-art tools can only be
used to detect specific kinds of compatibility issues (i.e., compatibility
issues caused by API signature evolution), i.e., many other essential types of
compatibility issues are still unrevealed. For example, customized OS versions
on real devices and semantic changes of OS could lead to serious compatibility
issues, which are non-trivial to be detected statically. To this end, we
propose a novel, lightweight, crowdsourced testing approach, LAZYCOW, to fill
this research gap and enable the possibility of taming Android fragmentation
through crowdsourced efforts. Specifically, crowdsourced testing is an emerging
alternative to conventional mobile testing mechanisms that allow developers to
test their products on real devices to pinpoint platform-specific issues.
Experimental results on thousands of test cases on real-world Android devices
show that LAZYCOW is effective in automatically identifying and verifying
API-induced compatibility issues. Also, after investigating the user experience
through qualitative metrics, users' satisfaction provides strong evidence that
LAZYCOW is useful and welcome in practice
Entrained Collective Rhythms of Multicellular Systems: Partial Impulsive Control Strategy
This paper is concerned with the study of entrained collective rhythms of multicellular systems by using partial impulsive control strategy. The objective is to design an impulsive controller based on only those partially available cell states, so that the entrained collective rhythms are guaranteed for the multicellular systems with cell-to-cell communication mechanism. By using the newly developed impulsive integrodifferential inequality, the sufficient conditions are derived to achieve the entrained collective rhythms of multicellular systems. A synthetic multicellular system with simulation results is finally given to illustrate the usefulness of the developed results
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