Highly efficient reverse transfection with siRNA in multiple wells of microtiter plates

We have developed an efficient and inexpensive method of reverse transfection from the solid phase to suppress genes with siRNA. The method enabled the realization of (i) a high efficiency of transfection; (ii) transfection of various types of cell; (iii) a high efficiency of gene knockdown by siRNA; (iv) a low toxicity to cells; and (v) a long-term stabilization (more than 210 d) of attached transfection mixture including siRNA in multiple wells. Although array-based reverse transfection has advantages in terms of miniaturization, the method has the advantage of enabling the inclusion of various soluble factors, such as humoral factors, drugs and ligands that affect gene expression, because the liquid phase is partitioned within the individual wells of each microtiter plate. Our method of reverse transfection with siRNA in multiple wells is a powerful and high-throughput tool for the analysis of signaling pathways.     

Polymer electrolyte membranes derived from novel fluorine-containing poly(arylene ether ketone)s by controlled post-sulfonation

Precise assignment with ¹H, ¹³C and some two dimensional NMR measurements showed that sulfonation reaction by concentrated sulfuric acid at 30 °C of fluorine-containing poly(arylene ether ketone) copolymers derived from 4,4′-bis(2,4,5,6-pentafluorobenzoyl)diphenyl ether (BPDE) and 9,9-bis(4-hydroxypehnyl)fluorene (HF) and 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane (6FBA) yielded quantitative introduction of sulfonic groups onto 2- and 7-positions of fluorene ring in HF unit. A series of sulfonated poly(arylene ether ketone)s with different ion exchange capacity was prepared by using this method with different compositions of HF and 6FBA, and membranes obtained from these polymers were characterized by TGA, moisture and water uptake, proton conductivity, methanol permeability, and Fenton testing. These membranes showed sufficient thermal stability, high proton conductivity at high humidified condition for PEFC and good balance in proton conductivity in water and methanol permeability for DMFC. On the other hand, they showed relatively high swelling by water probably due to weak intermolecular interaction caused by the existence of fluorine atoms in the polymer structure.     

The Role of Leaky Gut in Nonalcoholic Fatty Liver Disease: A Novel Therapeutic Target

The liver directly accepts blood from the gut and is, therefore, exposed to intestinal bacteria. Recent studies have demonstrated a relationship between gut bacteria and nonalcoholic fatty liver disease (NAFLD). Approximately 10–20% of NAFLD patients develop nonalcoholic steatohepatitis (NASH), and endotoxins produced by Gram-negative bacilli may be involved in NAFLD pathogenesis. NAFLD hyperendotoxicemia has intestinal and hepatic factors. The intestinal factors include impaired intestinal barrier function (leaky gut syndrome) and dysbiosis due to increased abundance of ethanol-producing bacteria, which can change endogenous alcohol concentrations. The hepatic factors include hyperleptinemia, which is associated with an excessive response to endotoxins, leading to intrahepatic inflammation and fibrosis. Clinically, the relationship between gut bacteria and NAFLD has been targeted in some randomized controlled trials of probiotics and other agents, but the results have been inconsistent. A recent randomized, placebo-controlled study explored the utility of lubiprostone, a treatment for constipation, in restoring intestinal barrier function and improving the outcomes of NAFLD patients, marking a new phase in the development of novel therapies targeting the intestinal barrier. This review summarizes recent data from studies in animal models and randomized clinical trials on the role of the gut–liver axis in NAFLD pathogenesis and progression.     

High Capacity Li2S–Li2O–LiI Positive Electrodes with Nanoscale Ion-Conduction Pathways for All-Solid-State Li/S Batteries

All-solid-state lithium–sulfur (Li/S) batteries are promising next-generation energy-storage devices owing to their high capacities and long cycle lives. The Li₂S active material used in the positive electrode has a high theoretical capacity; consequently, nanocomposites composed of Li₂S, solid electrolytes, and conductive carbon can be used to fabricate high-energy-density batteries. Moreover, the active material should be constructed with both micro- and nanoscale ion-conduction pathways to ensure high power. Herein, a Li₂S–Li₂O–LiI positive electrode is developed in which the active material is dispersed in an amorphous matrix. Li₂S–Li₂O–LiI exhibits high charge–discharge capacities and a high specific capacity of 998 mAh g⁻¹ at a 2 C rate and 25 °C. X-ray photoelectron spectroscopy, X-ray diffractometry, and transmission electron microscopy observation suggest that Li₂O–LiI provides nanoscale ion-conduction pathways during cycling that activate Li₂S and deliver large capacities; it also exhibits an appropriate onset oxidation voltage for high capacity. Furthermore, a cell with a high areal capacity of 10.6 mAh cm^–2 is demonstrated to successfully operate at 25 °C using a Li₂S–Li₂O–LiI positive electrode. This study represents a major step toward the commercialization of all-solid-state Li/S batteries.     

Fabrication and Training of 3D Conductive Polymer Networks for Neuromorphic Wetware

The human brain possesses an exceptional information processing capability owing to the 3D and dense network architecture of numerous neurons and synapses. Brain-inspired neuromorphic hardware can also benefit from 3D architectures, such as high integration of circuits and acquisition of highly complex dynamical systems. In this study, for future 3D neuromorphic engineering, 3D conductive polymer networks consisting of poly(3,4-ethylenedioxy-thiophene) doped with poly(styrene sulfonate) anions (PEDOT:PSS) are successfully and stably fabricated between multiple electrodes from scratch in precursor solution by electropolymerization. The networks efficiently emulate the 3D local connections between neighboring neurons observed in the cortex. This novel technology, which allows 3D conductive wiring only between desired electrodes, is unprecedented and has potential as an underlying technology for 3D integration. Furthermore, the experimental results also conclusively prove that conductance modification can be performed by manipulating the physical and chemical properties of 3D branch-wired conductive polymer wires, thus demonstrating for the first time the feasibility of neuromorphic wetware with enhanced biological plausibility in the subsequent post-Moore era.