| 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. |
- Liu, Zhigang, et al.
(författare)
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Gut microbiota mediates intermittent-fasting alleviation of diabetes-induced cognitive impairment
- 2020
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 11:1, s. 855-
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Tidskriftsartikel (refereegranskat)abstract
- Cognitive decline is one of the complications of type 2 diabetes (T2D). Intermittent fasting (IF) is a promising dietary intervention for alleviating T2D symptoms, but its protective effect on diabetes-driven cognitive dysfunction remains elusive. Here, we find that a 28-day IF regimen for diabetic mice improves behavioral impairment via a microbiota-metabolites-brain axis: IF enhances mitochondrial biogenesis and energy metabolism gene expression in hippocampus, re-structures the gut microbiota, and improves microbial metabolites that are related to cognitive function. Moreover, strong connections are observed between IF affected genes, microbiota and metabolites, as assessed by integrative modelling. Removing gut microbiota with antibiotics partly abolishes the neuroprotective effects of IF. Administration of 3-indolepropionic acid, serotonin, short chain fatty acids or tauroursodeoxycholic acid shows a similar effect to IF in terms of improving cognitive function. Together, our study purports the microbiota-metabolites-brain axis as a mechanism that can enable therapeutic strategies against metabolism-implicated cognitive pathophysiologies.
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| 3. |
- Song, Yang, et al.
(författare)
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Contact Wire Irregularity Stochastics and Effect on High-Speed Railway Pantograph-Catenary Interactions
- 2020
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0018-9456 .- 1557-9662. ; 69:10, s. 8196-8206
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Tidskriftsartikel (refereegranskat)abstract
- In high-speed rail operations, contact wire irregularity (CWI) in a catenary is a common disturbance to the pantograph-catenary interaction performance, which directly affects the quality of current collection. To describe the pointwise stochastics of CWI, the power spectral density (PSD) function for CWI is proposed, and its effect on the pantograph-catenary interaction is investigated. First, a preprocessing procedure is proposed to eliminate the redundant information in the measured irregularities based on the ensemble empirical mode decomposition (EEMD). Then, the upper envelope of the irregularity, which contains all the information regarding the dropper positions on the contact wire, is extracted. A form of the PSD function is suggested for contact wire irregularities. A methodology is proposed to include the effect of random irregularities in the assessment of the interaction performance of a pantograph-catenary. A developed target configuration under dead load (TCUD) method is used to calculate the initial configuration of the catenary, in which the dropper points on the contact wire are placed on their exact positions. Finally, the effect of the random contact wire irregularities on the contact force is investigated through 500 numerical simulations at each operating speed. The present results indicate that random irregularities have a direct impact on the pantograph-catenary contact, including an increment in the dispersion of the contact force statistics. The stochastic analysis shows that over 70% of the results with irregularities are worse than the ideal result without irregularities.
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| 4. |
- Wang, Zhigang, et al.
(författare)
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Decreased Splenic CD4(+) T-Lymphocytes in Apolipoprotein M Gene Deficient Mice
- 2015
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Ingår i: BioMed Research International. - : Hindawi Limited. - 2314-6133 .- 2314-6141.
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Tidskriftsartikel (refereegranskat)abstract
- Spleen T-lymphocytes, especially CD4(+) T-cells, have been demonstrated to be involved in broad immunomodulation and host-defense activity in vivo. Apolipoprotein M gene (apoM) may have an important role in the regulation of immunoprocess and inflammation, which could be hypothesized to the apoM containing sphingosine-1-phosphate (S1P). In the present study we demonstrate that the splenic CD4(+) T-lymphocytes were obviously decreased in the apoM gene deficient (apoM(-/-)) mice compared to the wild type (apoM(+/+)). Moreover, these mice were treated with lipopolysaccharide (LPS) and it was found that even more pronounced decreasing CD4(+) T-lymphocytes occurred in the spleen compared to the apoM(+/+) mice. The similar phenomena were found in the ratio of CD4(+)/CD8(+) T-lymphocytes. After administration of LPS, the hepatic mRNA levels of tumor necrosis factor-alpha (TNF-alpha) and monocyte chemotactic protein-1 (MCP-1) were markedly increased; however, there were no statistical differences observed between apoM(+/+) mice and apoM(-/-) mice. The present study demonstrated that apoM might facilitate the maintenance of CD4(+) T-lymphocytes or could modify the T-lymphocytes subgroups in murine spleen, which may further explore the importance of apoM in the regulation of the host immunomodulation, although the detailed mechanism needs continuing investigation.
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| 5. |
- An, Hongbin, et al.
(författare)
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A method of manufacturing microfluidic contact lenses by using irreversible bonding and thermoforming
- 2018
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP PUBLISHING LTD. - 0960-1317 .- 1361-6439. ; 28:10
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present the development of microfluidic contact lenses, which is based on the advantages of wearable microfluidics and can have great potential in the ophthalmology healthcare field. The development consists of two parts; the manufacturing process and the usability tests of the devices. In the manufacturing process, we firstly extended silane coupling and surface modification to irreversibly bond plastic membranes with microchannel-molded silicone rubber, to form the plastic-PDMS plane assemblies, and then molded the plane into a contact lens by thermoforming. We systematically investigated the effects of thermoforming factors, heating temperatures and the terrace die's sphere radius on channels by using the factorial experiment design. In addition, various tests were conducted to verify the usability of the devices. Through blockage and leakage tests, the devices were proved to be feasible, with no channel-blockages and could stand high pressures. Through a wearing test, the contact lenses were confirmed to be harmless on the living body. Furthermore, by performing the manipulating test, the device was proved to be liquid-controllable. These works provide a foundation for the applications of microfluidic contact lenses in ophthalmology.
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| 6. |
- An, Hongbin, et al.
(författare)
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Microfluidic contact lenses for unpowered, continuous and non-invasive intraocular pressure monitoring
- 2019
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Ingår i: Sensors and Actuators A-Physical. - : Elsevier BV. - 0924-4247 .- 1873-3069. ; 295, s. 177-187
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Tidskriftsartikel (refereegranskat)abstract
- Intraocular pressure (IOP) is a crucial physiological indicator of the visual system and play a key role in the diagnosis and treatment of glaucoma. However, the current handheld single measurement tools for IOP sensing cannot meet the future demands for glaucoma management. Thus, here we present the microfluidic contact lens sensors that could provide unpowered, continuous and non-invasive IOP monitoring. The microfluidic contact lens is comprised of a sensing layer of the micropatterned soft-elastomer and a hard plastic reference layer. The devices use the annular sensing chamber filled with the dyed liquid and a sensing microchannel as the IOP transducer. Resulting from the volume variance of the sensing chamber and caused by the deformation of the sensing layer under pressure, the IOP signal is detected as the displacement change of the dyed liquid's interface in the sensing channel, and in which, the displacement change can be optically observed by using the smart-phone camera. Based on the silicone rubber model eyeball, the sensing mechanism of the devices with different design parameters (the position of the sensing chambers and the dimension of the sensing channels) are explored by using the theoretical analyses and experimental investigations. The characteristics of these microfluidic contact lens sensors are tested, in which, the maximum sensitivity of the device (with the sensing chamber of 8.5 mm in diameter and the sensing channel of 100 x 40 um in size) can be achieved to 0.708 mm/mmHg in a working range of 0 (4) over tilde0 mmHg. Also, cyclical tests were conducted and indicated that the devices had a good reversibility and Long-term stability. Furthermore, the device (with the sensing chamber of 5.0 mm in diameter and the sensing channel of 150 x 40 urn in size) was test on the porcine eyes ex vivo, showing a sensitivity of 0.2832 mm/mmHg in a range of 8 (3) over tilde2 mmHg and, the device had a good reproducibility to its IOP change. This work provides a promising approach for unpowered, continuous and non-invasive monitoring of IOP.
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| 7. |
- Chen, Peilin, et al.
(författare)
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Fabrication of a silver nanoparticle-coated collagen membrane with anti-bacterial and anti-inflammatory activities for guided bone regeneration
- 2018
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Ingår i: Biomedical materials. - 1748-6041. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- Alveolar bone loss is a common problem that affects dental implant placement. A barrier between the bone substitute and gingiva that can prevent fibro-tissue ingrowth, bacterial infection and induce bone formation is a key factor in improving the success of alveolar ridge reconstruction. This study aims to develop a bioactive collagen barrier material for guided bone regeneration, that is coupled with anti-bacterial and anti-inflammatory properties. We have evaluated two silver coating methods and found controllable and precise coating achieved by sonication compared with sputtering. The optimized AgNP-coated collagen membrane exhibited excellent anti-bacterial effects against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) with limited cellular toxicity. It also displayed effective anti-inflammatory effects by reducing the expression and release of inflammatory cytokines including IL-6 and TNF-alpha. Additionally, AgNP-coated collagen membranes were able to induce osteogenic differentiation of mesenchymal stem cells that guide bone regeneration. These findings demonstrate the potential application of AgNP-coated collagen membranes to prevent infection after bone graft introduction in alveolar ridge reconstruction.
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| 8. |
- Duan, Jinpei, et al.
(författare)
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Dual-Circulant Modulation for Modular Multilevel DC/DC Converters With Inherent Balance Capability
- 2023
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Ingår i: IEEE transactions on power electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0885-8993 .- 1941-0107. ; 38:7, s. 7958-7963
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Tidskriftsartikel (refereegranskat)abstract
- Modular multilevel dc/dc converters (MMDC) have emerged recently for medium-voltage dc applications. Under single-circulant modulation, the submodule (SM) capacitor voltages in MMDC are found to be evenly divided only at some specific modulation coefficients. To obtain the inherent balance capability under all modulation coefficients and expand the application range of circulant modulation, a simple dual-circulant modulation is proposed in this letter. On the basis of single-circulant modulation, the self-balancing of the SM capacitor voltages is realized by using the additional switching patterns generated by a simple circulant permutation method. The theoretical analysis of the proposed method is presented, and the inherent balance capability of MMDC under the dual-circulant modulation method is verified by experiments.
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| 9. |
- Fang, Shan, et al.
(författare)
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A Dynamic Transformation Car-Following Model for the Prediction of the Traffic Flow Oscillation
- 2024
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Ingår i: IEEE Intelligent Transportation Systems Magazine. - 1939-1390 .- 1941-1197. ; 16:1, s. 174-198
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Tidskriftsartikel (refereegranskat)abstract
- Car-following (CF) behavior is a fundamental of traffic flow modeling; it can be used for the virtual testing of connected and automated vehicles and the simulation of various types of traffic flow, such as free flow and traffic oscillation. Although existing CF models can replicate the free flow well, they are incapable of simulating complicated traffic oscillation, and it is difficult to strike a balance between accuracy and efficiency. This article investigates the error variation when the traffic oscillation is simulated by the intelligent driver model (IDM). Then, it divides the traffic oscillation into four phases (coasting, deceleration, acceleration, and stationary) by using the space headway of multiple steps. To simulate traffic oscillation between multiple human-driven vehicles, a dynamic transformation CF model is proposed, which includes the long-time prediction submodel [modified sequence-to-sequence (Seq2seq)] model, short-time prediction submodel (Transformer), and their dynamic transformation strategy]. The first submodel is utilized to simulate the coasting and stationary phases, while the second submodel is utilized to simulate the acceleration and deceleration phases. The results of experiments indicated that compared to K-nearest neighbors, IDM, and Seq2seq CF models, the dynamic transformation CF model reduces the trajectory error by 60.79–66.69% in microscopic traffic flow simulations, 7.71–29.91% in mesoscopic traffic flow simulations, and 1.59–18.26% in macroscopic traffic flow simulations. Moreover, the runtime of the dynamic transformation CF model (Inference) decreased by 14.43–66.17% when simulating the large-scale traffic flow.
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| 10. |
- Gao, Feng, et al.
(författare)
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Visible-light photocatalytic properties of weak magnetic BiFeO3 nanoparticles
- 2007
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Ingår i: Advanced Materials. - : Wiley-VCH Verlag. - 0935-9648 .- 1521-4095. ; 19:19, s. 2889-2892
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Tidskriftsartikel (refereegranskat)abstract
- Polycrystalline BiFeO3 nanoparticles (size 80-120 nm) are prepared by a simple sol-gel technique. Such nanoparticles are very efficient for photocatalytic decomposition of organic contaminants under irradiation from ultraviolet to visible frequencies. The BiFeO3 nanoparticles also demonstrate weak ferromagnetism of about 0.06 mu(B)/Fe at room temperature, in good agreement with theoretical calculations.
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