An All‐Organic Non‐aqueous Lithium‐Ion Redox Flow Battery

A non‐aqueous lithium‐ion redox flow battery employing organic molecules is proposed and investigated. 2,5‐Di‐tert‐butyl‐1,4‐bis(2‐methoxyethoxy)benzene and a variety of molecules derived from quinoxaline are employed as initial high‐potential and low‐potential active materials, respectively. Electrochemical measurements highlight that the choice of electrolyte and of substituent groups can have a significant impact on redox species performance. The charge‐discharge characteristics are investigated in a modified coin‐cell configuration. After an initial break‐in period, coulombic and energy efficiencies for this unoptimized system are ～70% and ～37%, respectively, with major charge and discharge plateaus between 1.8‐2.4 V and 1.7‐1.3 V, respectively, for 30 cycles. Performance enhancements are expected with improvements in cell design and materials processing.     

A High‐Energy‐Density Multiple Redox Semi‐Solid‐Liquid Flow Battery

A new concept of multiple redox semi‐solid‐liquid (MRSSL) flow battery that takes advantage of active materials in both liquid and solid phases, is proposed and demonstrated. Liquid lithium iodide (LiI) electrolyte and solid sulfur/carbon (S/C) composite, forming LiI‐S/C MRSSL catholyte, are employed to demonstrate this concept. Record volumetric capacity (550 Ah L^?1_catholyte) is achieved using highly concentrated and synergistic multiple redox reactions of LiI and sulfur. The liquid LiI electrolyte is found to increase the reversible volumetric capacity of the catholyte, improve the electrochemical utilization of the S/C composite, and reduce the viscosity of catholyte. A continuous flow test is demonstrated and the influence of the flow rate on the flow battery performance is discussed. The MRSSL flow battery concept transforms inactive component into bi‐functional active species and creates synergistic interactions between multiple redox couples, offering a new direction and wide‐open opportunities to develop high‐energy‐density flow batteries.     

Annulated Dialkoxybenzenes as Catholyte Materials for Non‐aqueous Redox Flow Batteries: Achieving High Chemical Stability through Bicyclic Substitution

1,4‐Dimethoxybenzene derivatives are materials of choice for use as catholytes in non‐aqueous redox flow batteries, as they exhibit high open‐circuit potentials and excellent electrochemical reversibility. However, chemical stability of these materials in their oxidized form needs to be improved. Disubstitution in the arene ring is used to suppress parasitic reactions of their radical cations, but this does not fully prevent ring‐addition reactions. By incorporating bicyclic substitutions and ether chains into the dialkoxybenzenes, a novel catholyte molecule, 9,10‐bis(2‐methoxyethoxy)‐1,2,3,4,5,6,7,8‐octahydro‐1,4:5,8‐dimethanenoanthracene (BODMA), is obtained and exhibits greater solubility and superior chemical stability in the charged state. A hybrid flow cell containing BODMA is operated for 150 charge–discharge cycles with a minimal loss of capacity.     

Designing Redox‐Stable Cobalt–Polypyridyl Complexes for Redox Flow Batteries: Spin‐Crossover Delocalizes Excess Charge

Redox‐active organometallic molecules offer a promising avenue for increasing the energy density and cycling stability of redox flow batteries. The molecular properties change dramatically as the ligands are functionalized and these variations allow for improving the solubility and controlling the redox potentials to optimize their performance when used as electrolytes. Unfortunately, it has been difficult to predict and design the stability of redox‐active molecules to enhance cyclability in a rational manner, in part because the relationship between electronic structure and redox behavior has been neither fully understood nor systematically explored. In this work, rational strategies for exploiting two common principles in organometallic chemistry for enhancing the robustness of pseudo‐octahedral cobalt–polypyridyl complexes are developed. Namely, the spin‐crossover between low and high‐spin states and the chelation effect emerging from replacing three bidentate ligands with two tridentate analogues. Quantum chemical models are used to conceptualize the approach and make predictions that are tested against experiments by preparing prototype Co‐complexes and profiling them as catholytes and anolytes. In good agreement with the conceptual predictions, very stable cycling performance over 600 cycles is found.     

High‐Voltage Oxygen‐Redox‐Based Cathode for Rechargeable Sodium‐Ion Batteries

Recently, anionic‐redox‐based materials have shown promising electrochemical performance as cathode materials for sodium‐ion batteries. However, one of the limiting factors in the development of oxygen‐redox‐based electrodes is their low operating voltage. In this study, the operating voltage of oxygen‐redox‐based electrodes is raised by incorporating nickel into P2‐type Na_2/3[Zn_0.3Mn_0.7]O₂ in such a way that the zinc is partially substituted by nickel. As designed, the resulting P2‐type Na_2/3[(Ni_0.5Zn_0.5)_0.3Mn_0.7]O₂ electrode exhibits an average operating voltage of 3.5 V and retains 95% of its initial capacity after 200 cycles in the voltage range of 2.3–4.6 V at 0.1C (26 mA g^?1). Operando X‐ray diffraction analysis reveals the reversible phase transition: P2 to OP4 phase on charge and recovery to the P2 phase on discharge. Moreover, ex situ X‐ray absorption near edge structure and X‐ray photoelectron spectroscopy studies reveal that the capacity is generated by the combination of Ni²⁺/Ni⁴⁺ and O^2?/O^1? redox pairs, which is supported by first‐principles calculations. It is thought that this kind of high voltage redox species combined with oxygen redox could be an interesting approach to further increase energy density of cathode materials for not only sodium‐based rechargeable batteries, but other alkali‐ion battery systems.     

High‐Performance Lithium‐Iodine Flow Battery

A cathode‐flow lithium‐iodine (Li–I) battery is proposed operating by the triiodide/iodide (I₃^?/I^?) redox couple in aqueous solution. The aqueous Li–I battery has noticeably high energy density (≈0.28 kWh kg^?1_cell) because of the considerable solubility of LiI in aqueous solution (≈8.2 m ) and reasonably high power density (≈130 mW cm^?2 at a current rate of 60 mA cm^?2, 328 K). In the operation of cathode‐flow mode, the Li–I battery attains high storage capacity (≈90% of the theoretical capacity), Coulombic efficiency (100% ± 1% in 2–20 cycles) and cyclic performance (>99% capacity retention for 20 cycles) up to total capacity of 100 mAh.     

Non‐genetic diversity modulates population performance

Biological functions are typically performed by groups of cells that express predominantly the same genes, yet display a continuum of phenotypes. While it is known how one genotype can generate such non‐genetic diversity, it remains unclear how different phenotypes contribute to the performance of biological function at the population level. We developed a microfluidic device to simultaneously measure the phenotype and chemotactic performance of tens of thousands of individual, freely swimming Escherichia coli as they climbed a gradient of attractant. We discovered that spatial structure spontaneously emerged from initially well‐mixed wild‐type populations due to non‐genetic diversity. By manipulating the expression of key chemotaxis proteins, we established a causal relationship between protein expression, non‐genetic diversity, and performance that was theoretically predicted. This approach generated a complete phenotype‐to‐performance map, in which we found a nonlinear regime. We used this map to demonstrate how changing the shape of a phenotypic distribution can have as large of an effect on collective performance as changing the mean phenotype, suggesting that selection could act on both during the process of adaptation.     

Large‐Scale Analysis of Redox‐Sensitive Conditionally Disordered Protein Regions Reveals Their Widespread Nature and Key Roles in High‐Level Eukaryotic Processes

Recently developed quantitative redox proteomic studies enable the direct identification of redox‐sensing cysteine residues that regulate the functional behavior of target proteins in response to changing levels of reactive oxygen species. At the molecular level, redox regulation can directly modify the active sites of enzymes, although a growing number of examples indicate the importance of an additional underlying mechanism that involves conditionally disordered proteins. These proteins alter their functional behavior by undergoing a disorder‐to‐order transition in response to changing redox conditions. However, the extent to which this mechanism is used in various proteomes is currently unknown. Here, a recently developed sequence‐based prediction tool incorporated into the IUPred2A web server is used to estimate redox‐sensitive conditionally disordered regions at a large scale. It is shown that redox‐sensitive conditional disorder is fairly widespread in various proteomes and that its presence strongly correlates with the expansion of specific domains in multicellular organisms that largely rely on extra stability provided by disulfide bonds or zinc ion binding. The analyses of yeast redox proteomes and human disease data further underlie the significance of this phenomenon in the regulation of a wide range of biological processes, as well as its biomedical importance.     

Graphene–Polymer Nanocomposite‐Based Redox‐Induced Electricity for Flexible Self‐Powered Strain Sensors

Graphene as a powerful inorganic material such as excellent conductivity and ideal mechanical strength has recently been extensively utilized to develop flexible strain sensors. However, graphene‐based strain sensors usually suffer from the deficiencies of stretchability, sensitivity, and sensing range, which can restrict their applications in wearable devices. Here, a novel strain sensor is designed by integrating graphene/ecoflex film and meandering zinc wire into the flexible base. The constructed strain sensor not only possesses high stretchability of up to 150% strain but can also self‐generates current signals from redox‐induced electricity, where the stable current and voltage signals of about 75 µA and 0.83 V can be obtained, respectively. Furthermore, the self‐powered sensor presents a broad and linear sensing range of 25% to 150% strains and a fast response time of less than 0.11 s. Attached on human body, the sensor has been utilized to realize the motion detection of knee joint.     

Non‐Parametric Selected Ranked Set Sampling

A nonparametric selected ranked set sampling is suggested. The estimator of population mean based on the new approach is compared with that using the simple random sampling (SRS), the ranked set sampling (RSS) and the median ranked set sampling (MRSS) methods. The estimator of population mean using the new approach is found to be more efficient than its counter‐parts for almost all the cases considered.     

Carcinoma‐associated fibroblasts: Non‐neoplastic tumour‐promoting mesenchymal cells

Cancerous stroma coevolves alongside tumour progression, thereby promoting the malignant conversion of epithelial carcinoma cells. To date, an abundance of data have supported crucial roles of the tumour microenvironment (TME) in providing cancer cells with proliferative, migratory, survival and invasive propensities favouring the processes of tumourigenesis. The cancerous reactive stroma is frequently populated by a large number of myofibroblasts (MFs), which are activated, non‐transformed fibroblasts expressing α‐smooth muscle actin (α‐SMA). MFs together with non‐MF cells present in the tumour‐associated stroma are collectively referred to as carcinoma‐associated fibroblasts (CAFs), one of the major stromal cell types recognised in various human carcinomas. Recruitment of fibroblasts and/or their progenitors to a tumour mass and their subsequent transdifferentiation into MFs, as well as ongoing maintenance of their activated state, are believed to be essential processes facilitating tumour progression. However, the complex networks of signalling pathways mediating the phenotypic conversion into CAFs, as well as those underlying their tumour‐promoting interactions with other tumour‐constituting cells, have yet to be fully explored. Histopathological confirmation of the presence of large numbers of CAF MFs within TME and their altered gene expression profiles are known to be associated with disease progression and to serve as independent negative prognostic factors for a wide range of tumour types. In this review, we examine the current evidence shedding light on the emerging roles of tumour‐promoting CAFs, cells that are pivotal for epithelial cancer development and progression, and discuss the therapeutic potential of targeting these cells. J. Cell. Physiol. 228: 1651–1657, 2013. © 2013 Wiley Periodicals, Inc.     

Against Harmful Research on Non‐Agreeing Children

The Code of Federal Regulations permits harmful research on children who have not agreed to participate, but I will argue that it should be no more permissive of harmful research on such children than of harmful research on adults who have not agreed to participate. Of course, the Code permits harmful research on adults. Such research is not morally problematic, however, because adults must agree to participate. And, of course, the Code also permits beneficial research on children without needing their explicit agreement. This sort of research is also not problematic, this time because paternalism towards children may be justifiable. The moral problem at the center of this paper arises from the combination of two potential properties of pediatric research, first that it might be harmful and second that its subjects might not agree to participate. In Section 2 of this article I explain how the Code permits harmful research on non‐agreeing children. Section 3 contains my argument that we should no more permit harmful research on non‐agreeing children than on non‐agreeing adults. In Section 4, I argue that my thesis does not presuppose that pediatric assent has the same moral force that adult consent does. In Section 5, I argue that the distinction between non‐voluntary and involuntary research is irrelevant to my thesis. In Section 6, I rebut an objection based on the power of parental permission. In Section 7 I suggest how the Code of Federal Regulations might be changed.