Modulation of adipose tissue metabolism by microbial-derived metabolites

Obesity and its complications, including type 2 diabetes, cardiovascular disease, and certain cancers, have posed a significant burden on health and healthcare systems over the years due to their high prevalence and incidence. Gut microbial derivatives are necessary for the regulation of energy metabolism and host immunity, as well as for maintaining homeostasis of the intestinal environment. Gut flora metabolites may be a link between gut microbes and diseases, such as obesity, and help understand why alterations in the microbiota can influence the pathophysiology of human disease. This is supported by emerging evidence that microbial-derived metabolites, such as short-chain fatty acids, bile acids, tryptophan, trimethylamine-N-oxide, and lipopolysaccharides, can be beneficial or detrimental to the host by affecting organs outside the gut, including adipose tissue. Adipose tissue is the largest lipid storage organ in the body and an essential endocrine organ that plays an indispensable role in the regulation of lipid storage, metabolism, and energy balance. Adipose tissue metabolism includes adipocyte metabolism (lipogenesis and lipolysis), thermogenesis, and adipose tissue metabolic maladaptation. Adipose tissue dysfunction causes the development of metabolic diseases, such as obesity. Here, we review the current understanding of how these microbial metabolites are produced and discuss both established mechanisms and the most recent effects of microbial products on host adipose tissue metabolism. We aimed to identify novel therapeutic targets or strategies for the prevention and treatment of obesity and its complications

Stretchable elastic synaptic transistors for neurologically integrated soft engineering systems

Artificial synaptic devices that can be stretched similar to those appearing in soft-bodied animals, such as earthworms, could be seamlessly integrated onto soft machines toward enabled neurological functions. Here, we report a stretchable synaptic transistor fully based on elastomeric electronic materials, which exhibits a full set of synaptic characteristics. These characteristics retained even the rubbery synapse that is stretched by 50%. By implementing stretchable synaptic transistor with mechanoreceptor in an array format, we developed a deformable sensory skin, where the mechanoreceptors interface the external stimulations and generate presynaptic pulses and then the synaptic transistors render postsynaptic potentials. Furthermore, we demonstrated a soft adaptive neurorobot that is able to perform adaptive locomotion based on robotic memory in a programmable manner upon physically tapping the skin. Our rubbery synaptic transistor and neurologically integrated devices pave the way toward enabled neurological functions in soft machines and other applications

Active Layer Modification of Organic Photovoltaics - Structural Impact of Conjugated Polymer and Using Inorganic Nano-material as Charge Transport Pathways

Thesis (Ph.D.)--University of Washington, 2013The potential of organic photovoltaics (OPVs) to be a low-cost and low-carbon renewable energy source has generated great interest in this field over the last decade. To obtain OPVs with higher efficiency, efforts have been devoted to improving the properties of the active layer materials (the conjugated polymers and n-type materials), improving the fabrication processes, and understanding the many operating mechanisms. Besides the intrinsic materials properties, the morphology of the active layer has also been found to dramatically affect the performance of OPVs. Among these studies, two strategies are often used to develop OPVs with higher efficiency: (1) Develop new device structure; (2) Design and synthesize conjugated polymer with better properties for OPV application. In this thesis, a project based on each strategy will be discussed. The first strategy leads to a serial studies and process method developments on using inorganic nanomaterial as charge transport pathways in OPVs (Chapter 2). On the other hand, as understanding the structure-property relationship of conjugated polymers is very helpful in using the second strategy to improve OPVs, two different structures -- silafluorene containing multi-fused heptacylic arenes as the donor in donor-acceptor conjugated polymer and fluorine substituents on the conjugated polymer backbone will be included in Chapter 3

Gut microbiota in obesity and nonalcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide with prevalence estimates ranging from 25% to 45%, increasing in parallel with that of obesity and diabetes. There are inherent links between the liver and the gut, with the two are all budding from the entoderm during development. The gut microbiota is a central regulator of host metabolism. The composition and function of the gut microbiota is dynamic and affected by many factors. The gut microbiota has been shown to affect lipid metabolism and lipid levels in blood and tissues, both in mice and humans. Furthermore, diseases linked to dyslipidemia, such as non-alcoholic liver disease and atherosclerosis, are associated with changes in gut microbiota profile. This review explores the role of the gut microbiota in the pathogenesis of nonalcoholic fatty liver disease, as well as the prospects of microbiota and treatment of the nonalcoholic fatty liver disease

Chemotaxis of <i>Meloidogyne incognita</i> Response to Rhizosphere Bacteria

Rhizosphere microorganisms and the volatile organic compounds (VOCs) produced by them take part in the regulation of the chemotaxis of nematodes. A total of 150 strains of rhizosphere bacteria were screened via a chemotaxis experiment with Meloidogyne incognita. Some isolates affected the behavior of the nematodes, including attraction, randomness, and repulsion. Volatile metabolites produced via the selected bacteria were associated with the chemotaxis of nematodes. M. incognita was highly attracted to decanal. In addition, dimethyl disulfide, 2,5-dimethylpyrazine, pentadecanoic acid, and palmitic acid were found to attract weakly M. incognita. Furthermore, the chemotaxis of M. incognita was tested in a pot experiment. The bacteria Bacillus sp. 1-50, Brevibacillus brevis 2-35, B. cereus 5-14, Chryseobacterium indologens 6-4, and VOC decanal could regulate the movement of M. incognita in the pot with or without plants. The results provide insights into rhizosphere microorganisms and their VOCs and how they regulate the chemotaxis of the nematodes

High-Efficiency Pre-Treatment Core Tube for Produced Water in the Main Cavity Coupled with Secondary Cavities and Its Application in the Bohai Heavy Oilfield

Improving the produced fluid yield is an effective measure for realizing the crude oil production capacity of offshore platforms. However, for offshore platforms employed in production, using the narrow space of the platform to expand the produced water treatment system is a significant problem. In this study, a highly efficient pre-treatment core tube was coupled with the main cavity and secondary cavities (MCSCs) based on a vane-type tubular separator and a cub-mother cyclone. The optimal inlet Reynolds number and processing capacity were determined according to the structure size of the MCSC, and the MCSC was applied to achieve highly efficient pre-treatment of produced water in a heavy oilfield in the Bohai Sea. The comprehensive evaluation indicators FA and FV were better than those used by current technology. When the influent oil content fluctuated around 2000 mg/L (average of 1772.81 mg/L), the oil content in the effluent was stable and below 200 mg/L (average of 106.44 mg/L), and the separation efficiency was nearly 94%. Compared to those of the current corrugated plate interceptor on the platform, the floor space was reduced by more than 60% and the separation efficiency increased by up to 65%

Low Bandgap Polymers Based on Silafluorene Containing Multifused Heptacylic Arenes for Photovoltaic Applications

A series of donor–acceptor copolymers based on a new silafluorene containing multifused heptacylic arenes have been designed and synthesized in order to further modulate and optimize their electronic and optical properties. Polymer solar cells based on a blend of these polymers and PC₆₁BM exhibited high open circuit voltages of up to 0.86 V. Through simple and straightforward engineering of molecular structures, the devices based on the PSiFDCTBT:PC₆₁BM (1:3.5 in wt %) blend provided, on average, a <i>V</i>_oc of 0.86 V, a <i>J</i>_sc of 8.8 mA/cm², a FF of 56%, delivering a PCE of 4.2%

An epicardial bioelectronic patch made from soft rubbery materials and capable of spatiotemporal mapping of electrophysiological activity

An epicardial bioelectronic patch is an important device for investigating and treating heart diseases. The ideal device should possess cardiac-tissue-like mechanical softness and deformability, and be able to perform spatiotemporal mapping of cardiac conduction characteristics and other physical parameters. However, existing patches constructed from rigid materials with structurally engineered mechanical stretchability still have a hard-soft interface with the epicardium, which can strain cardiac tissue and does not allow for deformation with a beating heart. Alternatively, patches made from intrinsically soft materials lack spatiotemporal mapping or sensing capabilities. Here, we report an epicardial bioelectronic patch that is made from materials matching the mechanical softness of heart tissue and can perform spatiotemporal mapping of electrophysiological activity, as well as strain and temperature sensing. Its capabilities are illustrated on a beating porcine heart. We also show that the patch can provide therapeutic capabilities (electrical pacing and thermal ablation), and that a rubbery mechanoelectrical transducer can harvest energy from heart beats, potentially providing a power source for epicardial devices. An epicardial patch made from materials that match the mechanical softness of heart tissue can perform spatiotemporal mapping of electrophysiological activity, as well as strain and temperature sensing, pacing and ablation therapies, and energy harvesting, while deforming with a beating heart