3D Printing of Functional Materials: Surface Technology and Structural Optimization

There has been a surge in interest of 3D printing technology in the recent 5 years with respect to the equipment and materials, because this technology allows one to create sophisticated and customized parts in a manner that is more efficient regarding both material and time consumption. However, 3D printing has not yet become a mainstream technology within the established manufacturing routes. One primary factor accounting for this slow progress is the lack of a broad variety of 3D printable materials, resulting in limited functions of 3D printed parts. To bridge this gap, I present an integrated strategy to fabricate a variety of functional materials/devices through the post-printing surface modification and target-motivated structural topology. A reusable 3D printed filter was first demonstrated to remove metal ions from water. This filter was functionalized with a layer of bio-adsorbent grown on its surface using post-printing modification, and the capacity was improved through structural optimization. To further improve the working efficiency, a customized 3D all-in-one printable material system was employed, which uses only one 3D printing material, but can realize various functionalities through a post-printing process. This material system is applicable for all types of photo-polymerization based 3D printing routes, including DLP, SLA, polyjet and other emerging technologies. It has significantly extended the capacity of current 3D printing technology. The 3D printed structures were converted into useful devices with new functions or new structural metamaterials with novel properties, that are attributed to both their materials composition and structural design. For example, we have showcased the magnetically manipulated robot, strength-enhanced lattice materials with high effective strength, ultralight metal materials and mechanical-metamaterials. In this thesis, a new generation of initiator-integrated material system was also developed. Beyond being able to successfully 3D print functional devices/materials with desirable properties, I also demonstrated that this initiator-laden material can be utilized to locally repair the surface damage, allowing a self-healing ability. In general, the developed 3D printing process that incorporates surface modification and structural topology enables a new class of functional devices/materials to be produced, and opens a door for further research and development of an increasing variety of 3D printing applications. Through the work presented in this dissertation, I substantially build upon and further establish the strategy and material system for 3D printing functional devices/materials, keeping in mind components, design, engineering and application

Quantum-dot gain without inversion:Effects of dark plasmon-exciton hybridization

We propose an initial-state-dependent quantum-dot gain without population inversion in the vicinity of a resonant metallic nanoparticle. The gain originates from the hybridization of a dark plasmon-exciton and is accompanied by efficient energy transfer from the nanoparticle to the quantum dot. This hybridization of the dark plasmon-exciton, attached to the hybridization of the bright plasmon-exciton, strengthens nonlinear light-quantum emitter interactions at the nanoscale, thus the spectral overlap between the dark and the bright plasmons enhances the gain effect. This hybrid system has potential applications in ultracompact tunable quantum devices.Physics, Condensed MatterSCI(E)[email protected]

Dapagliflozin relieves renal injury in a diabetic nephropathy model by inducing autophagy through regulation of miR-30e-5p/AKT/mTOR pathway

Purpose: To investigate the mechanism of action of dapagliflozin on diabetic nephropathy. Methods: A rat model of diabetic nephropathy was established by injection of fructose-streptozotocin. Blood glucose and urinary protein levels were measured, while histopathological changes in kidney tissues were determined by hematoxylin & eosin staining (H & E). Serum levels of creatinine (Cr), blood urea nitrogen (BUN), malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH), and lactate dehydrogenase (LDH) were evaluated by enzyme-linked immunosorbent assay (ELISA). Cell apoptosis and autophagy were investigated by evaluating apoptotic and autophagic protein expression by western blot. Results: Administration of fructose-streptozotocin increased the blood glucose level of the rats (p < 0.001) and induced pathological changes in the kidney tissues, including glomerulosclerosis, renal tubule dilation, and inflammatory cell infiltration of rats. However, long-term treatment with dapagliflozin attenuated the fructose-streptozotocin-induced increases in Cr, BUN, and urinary protein and reversed the fructose-streptozotocin-induced decrease in Bcl-2 expression and increases in Bax and cleaved PARP expression in diabetic rats. Dapagliflozin also reversed the increases in MDA and LDH and decreases in SOD and GSH in diabetic rats. The fructose-streptozotocin-induced increase in p62 expression and decreases in LC3 and Beclin 1 expression were reversed by dapagliflozin. It upregulated miR-30e-5p expression and downregulated phosphorylated AKT and mTOR expression in diabetic rats. MicroRNA-30e-5p targeted AKT and inhibition of miR-30e-5p attenuated the dapagliflozin-induced decrease in p-AKT and p-mTOR expression in diabetic rats. Conclusion: In fructose-streptozotocin-induced diabetic rats, dapagliflozin ameliorates kidney injury, suppresses cell apoptosis and oxidative stress, and promotes cell autophagy through upregulation of miR-30e-5p and inactivation of the AKT/mTOR pathway. Therefore, dapagliflozin is a potent therapeutic agent for the management of diabetic neuropathy

MiR-384 is associated with renal damage in lupus nephritis via regulation of TET3 expression

Purpose: To investigate the correlations between miR-384 expression and renal damage in lupus nephritis (LN).Methods: Lupus nephritis and normal tissues were collected during surgery. The relative miR-384 expression was evaluated by extracting RNA and performing quantitative real time PCR (qRT-PCR) assays. Expression of ten-eleven translocation (TET3) mRNA and protein were measured by qRT-PCR and western blotting, respectively. The 24-h urine protein, serum complement C3, and serum creatinine were determined using commercial enzyme-linked immunosorbent assay (ELISA) kits. TargetScan and luciferase assays were used to validate the binding site for miR-384 and its target mRNA. Relationships among miR-384, TET3, and renal damage were analyzed by Spearman rank-order correlation coefficients.Results: MiR-384 expression increased in LN tissues and was positively correlated with the activity index (AI) and chronicity index of LN, whereas miR-384 expression and serum complement C3 were negatively correlated. Positive correlations were observed between miR-384 expression and 24-h urine protein, serum creatinine, and systemic lupus erythematosus disease AI. TargetScan and luciferaseassays indicated that the TET3 3′-UTR was the direct target of miR-384. MiR-384 upregulation inhibited TET3 mRNA and protein  expression, and was negatively associated with renal damage in LN.Conclusion: MiR-384 upregulation contributes to renal damage in LN by targeting the 3′-UTR of TET3 mRNA, suggesting that miR-384 is a potential biomarker and therapeutic target in LN. Keywords: MiR-384, Renal damage, Lupus nephritis, Ten-eleven translocation, TET

Dimensional Analysis of Average Diameter of Bubbles for Bottom Blown Oxygen Copper Furnace

Average diameter of bubbles is important in copper furnace. Based on the principle of similarity, a slice water model of a furnace with bottom-blown oxygen in matte-smelting process was established. A high-speed camera was used to record images continuously and clearer pictures were selected for treatment. Finally, image processing software was used for obtaining the average diameter of the bubbles. The effects of different injection conditions and equipment factors such as the diameter of nozzle, the nozzle installing angle, and gas velocity on the average diameter of bubbles were studied with cold water model experiment, exploring the dispersion and disintegration rules of bubbles. According to experimental data and Buckingham’s theorem, by using dimensional analysis method, an empirical formula on average diameter of bubbles was established (dB=0.41666d0.29374θ-0.46572v-0.16725). It can be seen from the formula that nozzle installing angle and diameter of nozzle make the most impact on the average diameter of bubbles in bottom blown oxygen copper furnace

Hydroxide-based magneto-ionics: electric-field control of reversible paramagnetic-to-ferromagnetic switch in α{\alpha}-Co(OH)2_{2} films

Magneto-ionics has emerged as a promising approach to manipulate magnetic properties, not only by drastically reducing power consumption associated with electric current based devices but also by enabling novel functionalities. To date, magneto-ionics have been mostly explored in oxygen-based systems, while there is a surge of interests in alternative ionic systems. Here we demonstrate highly effective hydroxide-based magneto-ionics in electrodeposited ${\alpha}$-Co(OH)$_{2}$ films. The ${\alpha}$-Co(OH)$_{2}$, which is a room temperature paramagnet, is switched to ferromagnetic after electrolyte gating with a negative voltage. The system is fully, magnetically reversible upon positive voltage application. The origin of the reversible paramagnetic-to-ferromagnetic transition is attributed to the ionic diffusion of hydroxyl groups, promoting the formation of metallic cobalt ferromagnetic regions. Our findings demonstrate one of the lowest turn-on voltages reported for propylene carbonate gated experiments. By tuning the voltage magnitude and sample area we demonstrate that the speed of the induced ionic effect can be drastically enhanced.Comment: 27 pages, 4 figures. Supplementary Information: 6 pages with 3 figure

EFFECTS OF VIETNAMESE SOPHORA ROOT ON GROWTH, ADHESION, INVASION AND MOTILITY OF MELANOMA CELLS

Background: Vietnamese Sophora Root mainly contains active constituents such as alkaloids, and it has anti-tumour, antibacterial, and anti-inflammatory effects. The objective of the paper was to study the effects of Vietnamese Sophora Root on growth, adhesion, invasion and motility of mouse melanoma B16BL6 cells, and to preliminarily explore its mechanism of action. Materials and Methods: MTT assay was used to detect the effect of Vietnamese Sophora Root aqueous extract on B16BL6 cell proliferation. Cell adhesion assay, reconstituted basement membrane invasion assay and chemotactic motility assay were used to observe the effects of Vietnamese Sophora Root aqueous extract on adhesion, invasion and motility of B16BL6 cells. Results: Different concentrations of Vietnamese Sophora Root aqueous extracts had different degrees of inhibitory effects on B16BL6 proliferation. With the decrease of concentration, the proliferation inhibitory effect decreased and even turned to promoting effect. The extract significantly inhibited the adhesion of B16BL6 cells to the basement membrane component LN, and had a significant effect on both the invasive and migratory capacities of B16BL6 cells through the basement membrane. Conclusion: We concluded that the aqueous extract of Vietnamese Sophora Root can inhibit the proliferation of melanoma cells, as well as their adhesion and movement

Recent advances in the field of carbon-based cathode electrocatalysts for Zn-air batteries

Carbon-based catalysts are widely regarded as one of the most promising materials for energy storage and conversion technologies due to their high electrical conductivity as well as tunable micro- and nanostructures. Developing efficient, low-cost, and durable bifunctional carbon-based electrocatalysts remains challenging. In this review, the recent advances in the field of carbon-based oxygen reduction reaction/oxygen evolution reaction electrocatalysts for Zn-air batteries are briefly reviewed, focusing on the fabrication strategies of carbon-based electrocatalysts. Finally, the present challenges and perspectives in developing advanced bifunctional carbon-based electrocatalysts are outlined. This journal i