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Objective(s): Chemerin is associated with insulin resistance, obesity, and metabolic syndrome. α-lipoic acid (α-LA) is a potent antioxidant involved in the reduction of diabetic symptoms. This study aimed to investigate the relationship between chemerin and P38 MAPK in the progression of diabetic nephropathy (DN) and examine the effects of α-LA on chemerin-treated human mesangial cells (HMCs). Materials and Methods: HMCs were transfected with a chemerin-overexpressing plasmid. HMCs were also treated with high-glucose, chemerin, α-LA, PDTC (pyrrolidine dithiocarbamate ammonium, NF-κB p65 inhibitor), and/or SB203580 (P38 MAPK inhibitor). Cell proliferation was tested using the Cell Counting Kit-8 assay. Collagen type IV and laminin were tested by ELISA. Chemerin expression was detected by qRT-PCR. The chemerin receptor was detected by immunohistochemistry. Interleukin-6 (IL-6), tumor necrosis factor-a (TNF-α), nuclear factor-κBp-p65 (NF-κB p-p65), transforming growth factor-β (TGF-β), and p-P38 mitogen-activated protein kinase (p-P38 MAPK) were evaluated by western blot. Results: High-glucose culture increased the expression of the chemerin receptor. α-LA inhibited HMC proliferation. Chemerin overexpression increased collagen type IV and laminin expression. P38 MAPK signaling was activated by chemerin, resulting in up-regulation of IL-6, TNF-α, NF-κB p-p65, and TGF-β. SB203580, PDTC, and α-LA reversed the effects of chemerin, reducing IL-6, TNF-α, NF-κB p-p65, and TGF-β expression. Conclusion: Chemerin might be involved in the occurrence and development of DN. α-LA might prevent the effects of chemerin on the progression of DN, possibly via the P38 MAPK pathway.

The work in this thesis was motivated by the theoretical prediction that a pair of Majorana bound states (MBSs) will be formed in Josephson junctions (JJs), which consist of s-wave superconductors (SCs) and three-dimensional topological insulators (3D TIs). A fractional Josephson effect is expected in such JJs with a 4π-periodic current phase relation. Our JJs are based on the MBE-grwon (Bi1−xSbx)2Te3 (BST) film. Both planar JJs and sandwich JJs were fabricated and characterized by transport measurements. First, we discovered that SCs are formed by magnetron sputtering Pd onto BST film. The transition temperature (TC) and the upper critical field (HC2) of the SCs were characterized in Hall-bar devices based on Pd/BST bilayer films. To identify the SC phase in our samples, scanning transmission electron microscopy (STEM) Energy-dispersive x-ray spectroscopy (EDX) were performed. STEM and EDX analyses show the result that the self-formed PdTe1,2 SCs are epitaxially formed on the BST film. A planar SC-TI-SC JJ is built when two Pd electrodes are deposited on BST film with a small gap. A supercurrent and a Fraunhofer-like pattern were observed on this JJ, suggesting that BST film is proximitized by self-formed SCs successfully. To characterize the junction transparency, a superconducting quantum interference device (SQUID) was fabricated. A high transparency ∼ 0.96 is obtained based on the Octavio-Tinkham-Blonder-Klapwijk (OTBK) theory. For most of the planar JJs, the interface between SCs and TIs is on the surface of TI. The surface can be polluted by water and oxide layers during nanofabrication. While the interface is inside the TI film and the SCs are epitaxially grown in our device. These are possible reasons for the high junction transparency. However, there is a lack of features for the existence of multiple Andreev reflections, which is usually observed in high-transparency JJs. Epitaxial growth of a superconductor on the TI surface is still challenging. Our discovery of unexpected self-epitaxy to form SCs on the surface of BST makes the nanofabrication of devices with an epitaxial SC/TI interface much more straightforward. These devices provide a good platform to realize the Fu-Kane proposal in TIs to engineer a topological superconducting (TSC) state. Second, we found that SCs can also form when Pd is thermally-deposited onto BST films. The SCs of PdTe and PdTe2 with an “epitaxial” interface is confirmed by STEM and EDX analyses. It is different from the case of the sputter-deposited Pd. The Pd penetrates fully through the BST film when Pd was deposited by thermal evaporation. This finding opened the possibility to create a TI nanowire sandwiched by SCs, by converting the BST film into the SC and leaving only a narrow BST channel to remain as the pristine TI. TI nanowires are created in this way that is confirmed by STEM. The finding of the complete conversion of BST into SCs also opened the possibility to build SC-TI-SC sandwiched JJs. The TI nanowire was proximitized by self-formed SCs successfully. Standard Fraunhofer patterns were observed on such JJs, suggesting that the supercurrent is not due to a superconducting short-circuit and the distribution of the supercurrent is homogeneous. The junction transparency is about 0.8, and the resonance conductance peaks resulting from multiple Andreev reflection (MAR) were observed. The MAR feature observed with the index up to 9 and at temperatures up to 1.0 K which is close to the transition temperature of self-formed SCs, suggesting that the superconducting proximity effect in JJs is strong. Finally, we did the Shapiro measurements. The m = 1 Shapiro step is clearly missing at low frequencies and low power. Two possible topologically trivial origins of the first step missing are Landau-Zener transitions (LZTs) and hysteretic I − V characteristics. Temperature dependence of the Shapiro steps shows that the m = 1 step is still missing at a high enough temperature where the hysteretic I − V behavior is completely gone. Landau-Zener transition is considered when the junction transparency is close to 1, but our junction transparency is not that high.We proved that the origin of the missing first Shapiro step is neither hysteretic I−V characteristic nor Landau-Zener transitions. These phenomena are reproduced in another two devices. Hence, our Shapiro-step suggest that a 4π-periodic contribution in the sandwich JJs. This gives possible evidence for topological Majorana bound states.

Air-source heat pumps (ASHPs) have been widely used in domestic buildings. However, the regulation performance of ASHPs for indoor thermal comfort control is influenced by the factors such as cold draft and slow response to the variation in room temperature. In this paper, a range of experiments was carried out for 14 ASHPs in an indoor environmental chamber under both cooling and heating conditions. A multi-index comprehensive evaluation model including the questionnaire survey method, the weighted scoring method and the quartile algorithm method was then adopted to analyze the tested data in order to give some intuitive indices to evaluate the regulation performance of ASHPs for indoor thermal comfort control. The results showed that unsatisfied factor of the overall thermal comfort under the cooling conditions was reached to 71 %. Besides, the precision of the temperature control was poor in both cooling and heating conditions, which manifesting ASHPs need a novel matched adjust mode and more intelligent control system to meet thermal comfort requirement. This study provided a reference basis for evaluating ASHP’s regulation performance on indoor thermal comfort.

Recent years, the demand of cold products has been increasing. Its main features are high quality preservation, small batch sizes, and diverse product varieties, which are in line with current consumption patterns. However, the influence of many factors such as the development of the cold chain logistics enterprises in China now, and the cost has entered a period of slow development. Cold chain logistics distribution and inventory strategy issues become the key to achieve the lowest cost or benefit maximization for cold chain companies. The text has researched the background of M dessert company, and from two aspects of multi-temperature coarrangement and inventory strategy of cold-chain logistics to study. Firstly, the cost as the objective function, considers the constraints such as cargo loading, and establishes a multi-temperature co-provisioning and integration optimization mathematical model under load constraints. The particle swarm optimization algorithm was improved and the improved particle swarm algorithm was used to solve the model. Taking M dessert company as an example, MATLAB R2009a software was used to solve the problem, and the effectiveness of the model was verified. Secondly, this paper establishes an inventory control model with the goal of maximizing profit, The inventory of cold chain products can create value. This paper takes profit maximization as an objective function, considers the overdue loss rate of foods and the time allowed in the warehouse, and formulates inventory control strategies. The various models and research methods proposed not only have a theoretical guiding role for M dessert company, but also can provide reference for other similar cold chain companies in the future.