Designing and Studying Redox-Active Molecules for Energy Storage and Desalination

Since the fast growth of the global population, energy scarcity has become a new threat to modern society. Those commonly seen resources like fossil, coal, and natural gas are nonrenewable energies, which cannot be replenished by human-scale time. In contrast, wind, solar, and hydropower are the three main renewable green energies under development with great efforts around the world. However, the intermittent character of these powers raises a new question: how to store them properly on large scales? By 2021, more than 90% of the electricity storage was taken by Lithium-ion batteries (LIBs). The usage of lithium brings concerns about its limited amount and high reactivity, and thus urgent to look for a replacement. Under this situation, redox-flow batteries (RFBs) were recognized as a promising class for large-scale renewable energy storage. Unlike conventional solid- state batteries in daily portable devices, RFBs use electrolytes, which is a kind of solution that contains dissolved redox-active materials, for electricity storage. The general construction of RFBs contains two electrolyte tanks and a center reaction site that has been divided into two polars by a separator (membrane). Such an architecture separates the power-producing site and the energy-storing site, which is a merit that cannot be accomplished by LIBs. This character offers the chance to change one parameter while holding the other one intact within a single device. The study of RFBs has passed through decades with the two most advanced designs, all vanadium RFBs (VRFBs) and Zinc-Bromine RFBs (ZBRFBs), that have been commercialized. Nevertheless, due to the high cost of vanadium and toxicity for both vanadium and bromine species, the development focus has switched from inorganic materials to organic materials. Organic compounds incorporate earth-abundant elements like C, H, O, N, etc., and have high flexibility to fabricate their structures. By modifying the organic molecules, they could achieve desired solubilities (energy), redox potentials (energy & power), and material stabilities (lifetime). The efforts in my graduate studies have been put into designing two aqueous- based viologen materials and studying the chemical stability of (2,2,6,6- tetramethylpiperidin-1-yl)oxyl (TEMPO). Inclusive analysis of physiochemical and electrochemical properties and battery demonstrations have been made using numerous techniques. After the work with material development, a further study on desalination RFBs has been made to establish a relationship between the battery parameter and the desalination performance

Microwave-Assisted Oxidation of Electrospun Turbostratic Carbon Nanofibers for Tailoring Energy Storage Capabilities

We report the systematic structural manipulation of turbostratic electrospun carbon nanofibers (ECNFs) using a microwave-assisted oxidation process, which is extremely rapid and highly controllable and affords controlled variation of the capacitive energy storage capabilities of ECNFs. We find a nonmonotonic relationship between the oxidation degree of ECNFs and their electrocapacitive performance and present a detailed study on the electronic and crystalline structures of ECNFs to elucidate the origin of this nonmonotonic relation. The ECNFs with an optimized oxidation level show ultrahigh capacitances at high operation rates, exceptional cycling performance, and an excellent energy–power combination. We have identified three key factors required for optimal energy storage performance for turbostratic carbon systems: (i) an abundance of surface oxides, (ii) microstructural integrity, and (iii) an appropriate interlayer spacing

MiR-20a regulates the PRKG1 gene by targeting its coding region in pulmonary arterial smooth muscle cells

AbstractChronic hypoxia triggers pulmonary vascular remodeling, which is associated with de-differentiation of pulmonary artery smooth muscle cells (PASMC). Here, we show that miR-20a expression is up-regulated in response to hypoxia in both mouse and human PASMC. We also observed that miR-20a represses the protein kinase, cGMP-dependent, type I (PRKG1) gene and we identified two crucial miR-20a binding sites within the coding region of PRKG1. Functional studies showed that miR-20a promotes the proliferation and migration of human PASMC, whereas it inhibits their differentiation. In summary, we provided a possible mechanism by which hypoxia results in decreased PRKG1 expression and in the phenotypic switching of PASMC

Highly Active Nanostructured CoS2/CoS Heterojunction Electrocatalysts for Aqueous Polysulfide/Iodide Redox Flow Batteries

Aqueous polysulfide/iodide redox flow batteries are attractive for scalable energy storage due to their high energy density and low cost. However, their energy efficiency and power density are usually limited by poor electrochemical kinetics of the redox reactions of polysulfide/iodide ions on graphite electrodes, which has become the main obstacle for their practical applications. Here, CoS2/CoS heterojunction nanoparticles with uneven charge distribution, which are synthesized in situ on graphite felt by a one-step solvothermal process, can significantly boost electrocatalytic activities of I−/I3− and S2−/Sx2−redox reactions by improving absorptivity of charged ions and promoting charge transfer. The polysulfide/iodide flow battery with the graphene felt-CoS2/CoS heterojunction can deliver a high energy efficiency of 84.5% at a current density of 10 mA cm−2, a power density of 86.2 mW cm−2 and a stable energy efficiency retention of 96% after approximately 1000 h of continuous operation

Secondary infection with Streptococcus suis serotype 7 increases the virulence of highly pathogenic porcine reproductive and respiratory syndrome virus in pigs

<p>Abstract</p> <p>Background</p> <p>Porcine reproductive and respiratory syndrome virus (PRRSV) and <it>Streptococcus suis </it>are common pathogens in pigs. In samples collected during the porcine high fever syndrome (PHFS) outbreak in many parts of China, PRRSV and <it>S. suis </it>serotype 7 (SS7) have always been isolated together. To determine whether PRRSV-SS7 coinfection was the cause of the PHFS outbreak, we evaluated the pathogenicity of PRRSV and/or SS7 in a pig model of single and mixed infection.</p> <p>Results</p> <p>Respiratory disease, diarrhea, and anorexia were observed in all infected pigs. Signs of central nervous system (CNS) disease were observed in the highly pathogenic PRRSV (HP-PRRSV)-infected pigs (4/12) and the coinfected pigs (8/10); however, the symptoms of the coinfected pigs were clearly more severe than those of the HP-PRRSV-infected pigs. The mortality rate was significantly higher in the coinfected pigs (8/10) than in the HP-PRRSV- (2/12) and SS7-infected pigs (0/10). The deceased pigs of the coinfected group had symptoms typical of PHFS, such as high fever, anorexia, and red coloration of the ears and the body. The isolation rates of HP-PRRSV and SS7 were higher and the lesion severity was greater in the coinfected pigs than in monoinfected pigs.</p> <p>Conclusion</p> <p>HP-PRRSV infection increased susceptibility to SS7 infection, and coinfection of HP-PRRSV with SS7 significantly increased the pathogenicity of SS7 to pigs.</p

Activated mouse CD4+Foxp3−CD4^+Foxp3^− T cells facilitate melanoma metastasis via Qa-1-dependent suppression of NK-cell cytotoxicity

The regulatory activities of mouse $CD^4+Foxp3^+$ T cells on various immune cells, including NK cells, have been well documented. Under some conditions, conventional $CD4^+Foxp3^−$ T cells in the periphery are able to acquire inhibitory function on other T cells, but their roles in controlling innate immune cells are poorly defined. As a potential cellular therapy for cancer, ex vivo activated $CD4^+Foxp3^−$ effector T cells are often infused back in vivo to suppress tumor growth and metastasis. Whether such activated T cells could affect NK-cell control of tumorigenesis is unclear. In the present study, we found that mitogen-activated $CD4^+Foxp3^−$ T cells exhibited potent suppressor function on NK-cell proliferation and cytotoxicity in vitro, and notably facilitated B16 melanoma metastasis in vivo. Suppression of NK cells by activated $CD4^+Foxp3^−$ T cells is cell-cell contact dependent and is mediated by Qa-1:NKG2A interaction, as administration of antibodies blocking either Qa-1 or NKG2A could completely reverse this suppression, and significantly inhibited otherwise facilitated melanoma metastasis. Moreover, activated $CD4^+Foxp3^−$ cells from Qa-1 knockout mice completely lost the suppressor activity on NK cells, and failed to facilitate melanoma metastasis when transferred in vivo. Taken together, our findings indicate that innate anti-tumor response is counter regulated by the activation of adaptive immunity, a phenomenon we term as “activation-induced inhibition”. Thus, the regulatory role of activated $CD4^+Foxp3^−$ T cells in NK-cell activity must be taken into consideration in the future design of cancer therapies

Review and development of surrounding rock control technology for gob-side entry retaining in China

The research and application of gob-side entry retaining (GER) technology in Chinese coal mines has been over 60 years. Two major technical types including GER with filling and GER with roof cutting were developed. However, due to the complex mining and geological conditions of the mined-out coal seam in different mining areas, as well as the strong mining pressure behaviours in the retained roadway, the promotion and application of GER technology presented ups and downs. Firstly, the achievements and key technological advances in the main GER types in China, the principle of surrounding rock stability, road-in support technology, roadside support technology, adaptability evaluation and surrounding rock stability monitoring are summarized, and the application applicability of different technologies at this stage is analyzed. Then, the difficulties and challenges faced by current GER technology are summarized: there is still no systematic theory for GER with strong mining pressure; there are still shortcomings in the theoretical understanding of the interaction mechanism between the surrounding rock and the support body for GER with filling; the mechanical and deformation characteristics of the filling materials for the roadside support body are not yet suitable for GER in deep working faces or with strong mining pressure; the mechanism and control technology of floor heave for GER are not yet perfect; the research on stability control of filling body for GER under strong dynamic load or rock burst is still in a blank. Finally, concerned with such difficulties and challenges, several reserve technologies have been proposed: the coordinated control of controlled roof cutting and filling for GER in fully mechanized caving/ full-seam mining in the thick coal seam, and the GER technology with additive modified high-water materials in working faces with strong mining pressure; finally, a set of intelligent inversion workflow for rock mechanical parameters used in GER numerical simulations for GER is established, and an intelligent optimization design method for GER support parameters is proposed

Involvement of NMDA-AKT-mTOR Signaling in Rapid Antidepressant-Like Activity of Chaihu-jia-Longgu-Muli-tang on Olfactory Bulbectomized Mice

Background: Fast-onset antidepressants are urgently needed. Chaihu-jia-Longgu-Muli-tang (CLM), a classic Chinese herbal medicine, has been used for antidepressant treatment with long history. Olfactory bulbectomization (OB) model is validated for identification of rapid antidepressant efficacy. Here we used OB model for investigating the rapid onset activity of CLM in mice, and also tested the involvement of prefrontal Akt-mTOR and associated AMPA/NMDA receptors as well as hippocampal BDNF in the rapid antidepressant-like effect of CLM.Methods: The OB model was first characterized with depression-like behaviors and the time course changes of the behaviors. The fast onset of antidepressant effect of CLM was evaluated using sucrose preference test, tail suspension test and forced swim test in OB mice after a single administration. The expression of synaptic proteins of AMPA and NMDA subunits as well as Akt/mTOR signaling in the prefrontal cortex, and hippocampal BDNF was evaluated with the immunoblotting method.Results: A single dose of CLM significantly improved the deficiency in the sucrose preference and decreased the immobility time in the tail suspension test in OB mice. In the prefrontal cortex (PFC) in OB mice, there was lower expression level of the AMPA receptor subunit GluR1, rescued by a single dose of CLM. Additionally, the expression of NMDA subunit NR1 was up-regulated in OB mice, whereas mTOR and its upstream Akt signalings were both down-regulated. These deficiencies were reversed by a single dose of CLM. The CLM treatment also attenuated the expressions of NMDA receptor subunits NR2A and NR2B, which did not change in OB mice. In the hippocampus, expressions of GluR1 and brain derived neurotrophic factor (BDNF) were both up-regulated in OB mice, although CLM increased GluR1, but not BDNF.Conclusion: CLM elicited rapid antidepressant-like effects in the OB model mice, and CLM reversal of the abnormality in PFC expression of AMPA and NMDA receptors and associated Akt-mTOR signaling may underlie the effects