| 1. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 2. |
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| 3. |
- Cui, Shaohua, et al.
(författare)
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Adaptive Collision-Free Trajectory Tracking Control for String Stable Bidirectional Platoons
- 2023
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Ingår i: IEEE Transactions on Intelligent Transportation Systems. - 1524-9050 .- 1558-0016. ; 24:11, s. 12141-12153
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Tidskriftsartikel (refereegranskat)abstract
- Autonomous vehicle (AV) platoons, especially those with the bidirectional communication topology, have significant practical value, as they not only increase link capacity and reduce vehicle energy consumption, but also reduce the consumption of communication resources. Small gaps between AVs in a platoon easily lead to emergency braking or even collisions between consecutive AVs. This paper applies barrier Lyapunov functions to collision avoidance between AVs in a bidirectional platoon during trajectory tracking. Based on backstepping technique, an adaptive collision-free platoon trajectory tracking control algorithm is developed to distributedly design control laws for each AV in the platoon. The control algorithm does not need to introduce additional car-following models to simulate AV driving, and only needs to integrate the position trajectories of consecutive AVs to avoid inter-vehicle collisions. Two sign functions are introduced into the control laws of each AV to ensure strong string stability for bidirectional AV platoons. Moreover, uncertainties and external disturbances in vehicle motion are effectively compensated by introducing adaptation laws. Strong string stability is rigorously proved. CarSIM-based comparison simulations verify the effectiveness of the proposed control algorithm in avoiding inter-vehicle collisions, compensating for uncertainties in vehicle motion, and suppressing the amplification of spacing errors along the platoon.
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| 4. |
- Cui, Shaohua, 1995, et al.
(författare)
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Delay-throughput tradeoffs for signalized networks with finite queue capacity
- 2024
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Ingår i: Transportation Research Part B: Methodological. - 0191-2615. ; 180
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Tidskriftsartikel (refereegranskat)abstract
- Network-level adaptive signal control is an effective way to reduce delay and increase network throughput. However, in the face of asymmetric exogenous demand, the increase of network performance via adaptive signal control alone is at the expense of service fairness (i.e., phase actuation fairness and network resource utilization fairness). In addition, for oversaturated networks, arbitrary adaptive signal control seems to have little effect on improving network performance. Therefore, under the assumption that the mean routing proportions/turn ratios of vehicles at intersections are fixed, this study investigates the problem of optimally allocating input rates to entry links and simultaneously finding a stabilizing signal control policy with phase fairness. We model the stochastic optimization problem of maximizing network throughput subject to network stability (i.e., all queue lengths have finite means) and average phase actuation constraints to bridge the gap between stochastic network stability control and convex optimization. Moreover, we further propose a micro-level joint admission and bounded signal control algorithm to achieve network stability and throughput optimization simultaneously. Joint control is implemented in a fully decomposed and distributed manner. For any arrival rate, joint control provably achieves network throughput within O(1/V) of optimality while trading off average delay with O(V), where V is an adjusted control parameter. Through a comparative simulation of a real network with 256 O-D pairs, the proposed joint control keeps network throughput at maximum, guarantees service fairness, and fully utilizes network capacity (i.e., increases network throughput by 17.54%).
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| 5. |
- Cui, Shaohua, et al.
(författare)
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Temporal Finite-Time Adaptation in Controlling Quantized Nonlinear Systems Amidst Time-Varying Output Constraints
- 2024
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Ingår i: IEEE Transactions on Automation Science and Engineering. - 1558-3783 .- 1545-5955. ; In Press
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Tidskriftsartikel (refereegranskat)abstract
- Using the backstepping technique, this paper formulates innovative adaptive finite-time stabilizing controllers for uncertain nonlinear systems featuring nonuniform input quantization and asymmetric, time-varying output constraints. These novel controllers leverage the consistent characteristics of both hysteresis quantizers and logarithmic quantizers. Quantization errors, when consistent, become unbounded and contingent on control input, rendering them incompatible with the growth conditions of nonlinear systems. Consequently, the developed adaptive controllers eliminate the reliance on growth conditions, effectively addressing the impact of unbounded quantization errors on finite-time stability. This adaptability allows the controllers to function effectively with systems employing either hysteresis quantizers or logarithmic quantizers. The paper establishes the convergence of these controllers through the finite-time Lyapunov stability theorem. It also provides a comprehensive guideline for tuning settling time, enabling fine-grained control over finite-time convergence and adjustable tracking error performance. Additionally, the controllers rigorously maintain system output within predefined limits. Their effectiveness and low computational burden are demonstrated through three comparative numerical simulations and a practical simulation in collision-free trajectory tracking control of an autonomous vehicle platoon using the vehicle motion software CarSim. These simulations confirm the advanced performance of the adaptive controllers. Note to Practitioners—This paper introduces an innovative approach to control uncertain nonlinear systems encountering intricate input quantization and output constraints. Employing the sophisticated backstepping technique, the authors present adaptive finite-time-stabilizing controllers engineered to address nonuniform input quantization and asymmetric, time-varying output restrictions. What distinguishes these controllers is their reliance on the consistent behavior exhibited by hysteresis and logarithmic quantizers. This unique feature equips them to effectively counteract unbounded quantization errors influenced by control input. Most notably, these controllers eliminate the conventional growth conditions typically demanded by nonlinear systems. As a result, they extend their applicability to a broad spectrum of systems employing either hysteresis or logarithmic quantizers. The research also provides practitioners with a valuable guideline for precisely adjusting settling time. This enables the attainment of desired convergence rates while permitting adaptable tracking error performance. Additionally, these controllers guarantee that the system’s output adheres to predefined limits. The practical significance of this study is highlighted through three comparative numerical simulations and a real-world application simulation. This real-world simulation involves collision-free trajectory tracking control of an autonomous vehicle platoon, executed using the vehicle motion software CarSim. These simulations unequivocally demonstrate the effectiveness and low computational burden of the developed controllers, thereby establishing them as a valuable resource for practitioners facing complex control challenges in various domains.
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| 6. |
- Han, Xue, et al.
(författare)
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Empirical analysis for Distributed Energy Resources' impact on future distribution network
- 2012
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Ingår i: Energy Conference and Exhibition (ENERGYCON), 2012 IEEE International. - : IEEE. - 9781467314541 ; , s. 731-737
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Konferensbidrag (refereegranskat)abstract
- There has been a large body of statements claiming that the large scale deployment of Distributed Energy Resources (DERs) will eventually reshape the future distribution grid operation in various ways. Thus, it is interesting to introduce a platform to interpret to what extent the power system operation will be alternated. In this paper, quantitative results in terms of how the future distribution grid will be changed by the deployment of distributed generation, active demand and electric vehicles, are presented. The analysis is based on the conditions for both a radial and a meshed distribution network. The input parameters are based on the current and envisioned DER deployment scenarios proposed for Sweden.
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| 7. |
- Han, Xue, et al.
(författare)
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Modelling Framework and the Quantitative Analysis of Distributed Energy Resources in Future Distribution Networks
- 2013
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Ingår i: International Journal of Emerging Electric Power Systems. - : De Gruyter. - 2194-5756 .- 1553-779X. ; 14:5, s. 421-431
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Tidskriftsartikel (refereegranskat)abstract
- There has been a large body of statements claiming that the large-scale deployment of Distributed Energy Resources (DERs) could eventually reshape the future distribution grid operation in numerous ways. Thus, it is necessary to introduce a framework to measure to what extent the power system operation will be changed by various parameters of DERs. This article proposed a modelling framework for an overview analysis on the correlation between DERs. Furthermore, to validate the framework, the authors described the reference models of different categories of DERs with their unique characteristics, comprising distributed generation, active demand and electric vehicles. Subsequently, quantitative analysis was made on the basis of the current and envisioned DER deployment scenarios proposed for Sweden. Simulations are performed in two typical distribution network models for four seasons. The simulation results show that in general the DER deployment brings in the possibilities to reduce the power losses and voltage drops by compensating power from the local generation and optimizing the local load profiles.
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| 8. |
- Liu, Jiale, et al.
(författare)
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STING inhibitors sensitize platinum chemotherapy in ovarian cancer by inhibiting the CGAS-STING pathway in cancer-associated fibroblasts (CAFs)
- 2024
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Ingår i: Cancer Letters. - : Elsevier. - 0304-3835 .- 1872-7980. ; 588
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Tidskriftsartikel (refereegranskat)abstract
- Chemotherapy resistance in ovarian cancer hampers cure rates, with cancer-associated fibroblasts (CAFs) playing a pivotal role. Despite their known impact on cancer progression and chemotherapy resistance, the specific mechanism by which CAFs regulate the tumor inflammatory environment remains unclear. This study reveals that cisplatin facilitates DNA transfer from ovarian cancer cells to CAFs, activating the CGAS-STING-IFNB1 pathway in CAFs and promoting IFNB1 release. Consequently, this reinforces cancer cell resistance to platinum drugs. High STING expression in the tumor stroma was associated with a poor prognosis, while inhibiting STING expression enhanced ovarian cancer sensitivity. Understanding the relevance of the CGAS-STING pathway in CAFs for platinum resistance suggests targeting STING as a promising combination therapy for ovarian cancer, providing potential avenues for improved treatment outcomes.
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| 9. |
- Liu, Yuwei, et al.
(författare)
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The effects of fermented rye products on gut microbiota and their association with metabolic factors in Chinese adults : an explorative study
- 2021
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Ingår i: Food & Function. - : Royal Society of Chemistry. - 2042-6496 .- 2042-650X. ; 12:19, s. 9141-9150
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Tidskriftsartikel (refereegranskat)abstract
- Rye is among the cereals with the highest content of dietary fibre. A high rye food intake has been associated with improved metabolic risk factors in some but not all observational and intervention studies. Whole-grain rye has also been suggested to affect the gut microbiota in individuals with metabolic syndrome. However, it is yet unclear to what extent effects on the gut microbiota mediate the beneficial metabolic responses of whole-grain rye intake. We hypothesized that a high intake of whole grain rye products containing fermented rye bran (FRB) vs. refined wheat based products (RW) could alter the gut microbiota and short-chain fatty acid (SCFA) composition towards a phenotype associated with beneficial metabolic effects in a population not used to such foods. For this purpose, we conducted a post hoc analysis of a 12-week randomized controlled trial in Chinese adults with Helicobacter pylori (HP) infection, with 53 participants consuming RW and 31 participants consuming FRB included in the analysis. Anthropometric measurements and fasting blood and fecal sample analyses as well as 13C-urea breath test were performed at baseline and after a 12-week intervention. At week 12, we observed a higher serum insulin concentration (P-value = 0.038) in the FRB group (n = 31) versus the RW group (n = 53), and this difference was corroborated with alterations in the genus-level relative abundances of the gut microbiota, represented by an increase in Romboutsia and a reduction in Bilophila in the FRB group (n = 22) versus the RW group (n = 46). Compared to the RW group (n = 53), fecal acetic acid concentration was significantly higher in the FRB group (n = 31) at week 12. We also found that fecal acetic and butyric acids positively, while isobutyric, isovaleric and 2-methylbutyric acids inversely, correlated with the gut Romboutsia level among all participants (n = 68) at week 12. We found positive correlations of fecal isobutyric, isovaleric and 2-methylbutyric acids with gut Bilophila (n = 68). In conclusion, our results suggest that the intake of high-fibre rye products could modify gut Romboutsia and Bilophila in a Chinese population with HP infection. These effects are paralleled with favorable modifications of the SCFA concentration and are associated with altered glycemic traits.
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| 10. |
- Liu, Yuwei, et al.
(författare)
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The effects of fermented rye products on gut microbiota and their association with metabolic factors in Chinese adults - an explorative study
- 2021
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Ingår i: Food and Function. - : Royal Society of Chemistry (RSC). - 2042-6496 .- 2042-650X. ; 12:19, s. 9141-9150
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Tidskriftsartikel (refereegranskat)abstract
- Rye is among the cereals with the highest content of dietary fibre. A high rye food intake has been associated with improved metabolic risk factors in some but not all observational and intervention studies. Whole-grain rye has also been suggested to affect the gut microbiota in individuals with metabolic syndrome. However, it is yet unclear to what extent effects on the gut microbiota mediate the beneficial metabolic responses of whole-grain rye intake. We hypothesized that a high intake of whole grain rye products containing fermented rye bran (FRB) vs. refined wheat based products (RW) could alter the gut microbiota and short-chain fatty acid (SCFA) composition towards a phenotype associated with beneficial metabolic effects in a population not used to such foods. For this purpose, we conducted a post hoc analysis of a 12-week randomized controlled trial in Chinese adults with Helicobacter pylori (HP) infection, with 53 participants consuming RW and 31 participants consuming FRB included in the analysis. Anthropometric measurements and fasting blood and fecal sample analyses as well as C-13-urea breath test were performed at baseline and after a 12-week intervention. At week 12, we observed a higher serum insulin concentration (P-value = 0.038) in the FRB group (n = 31) versus the RW group (n = 53), and this difference was corroborated with alterations in the genus-level relative abundances of the gut microbiota, represented by an increase in Romboutsia and a reduction in Bilophila in the FRB group (n = 22) versus the RW group (n = 46). Compared to the RW group (n = 53), fecal acetic acid concentration was significantly higher in the FRB group (n = 31) at week 12. We also found that fecal acetic and butyric acids positively, while isobutyric, isovaleric and 2-methylbutyric acids inversely, correlated with the gut Romboutsia level among all participants (n = 68) at week 12. We found positive correlations of fecal isobutyric, isovaleric and 2-methylbutyric acids with gut Bilophila (n = 68). In conclusion, our results suggest that the intake of high-fibre rye products could modify gut Romboutsia and Bilophila in a Chinese population with HP infection. These effects are paralleled with favorable modifications of the SCFA concentration and are associated with altered glycemic traits.
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