Redox flow cells for energy conversion Ponce de León, C.; Frías-Ferrer, A.; González-García, J. ...
Journal of power sources,
09/2006, Volume:
160, Issue:
1
Journal Article
Peer reviewed
Open access
Energy storage technologies provide an alternative solution to the problem of balancing power generation and power consumption. Redox flow cells are designed to convert and store electrical energy ...into chemical energy and release it in a controlled fashion when required. Many redox couples and cell designs have being evaluated. In this paper, redox flow systems are compared in the light of characteristics such as open circuit potential, power density, energy efficiency and charge-discharge behaviour. The key advantages and disadvantages of redox flow cells are considered while areas for further research are highlighted.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The interaction of L-Phe with the membrane components, i.e., lipids and proteins, has been discussed in the current literature due to the interest to understand the effect of single amino acids in ...relation to the formation of amyloid aggregates.
In the present work, it is shown that L-Phe interacts with 9:1 DMPC (1,2-dimyristoyl-sn-glycero-3 phosphocholine)/DPPC (1,2-dipalmitoyl-sn-glycero-3 phosphocholine) mixtures but not in the 1:9 one. An important observation is that the interaction disappears when DPPC is replaced by diether PC (2-di-O-hexadecyl-sn-glycero-3-phosphocholine) a lipid lacking carbonyl groups (CO). This denotes that CO groups may interact specifically with L-Phe in accordance with the appearance of a new peak observed by Infrared spectroscopy (FTIR-ATR). The interaction of L-Phe affects the compressibility pattern of the 9:1 DMPC/DPPC mixture which is congruent with the changes observed by Raman spectra.
The specific interaction of L-Phe with CO, propagates to phosphate and choline groups in this particular mixture as analyzed by FTIR-ATR spectroscopy and is absent when DMPC is dopped with diether PC.
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•L-Phe binds to 9:1 DMPC/DPPC mixtures•CO groups in the DPPC component are required.•Effect of L-Phe propagates to PO and choline groups.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZRSKP
The authors describe a label-free electrochemical biosensor based on CNTs for picogram range detection of the food carcinogen aflatoxin B1 (AFB1). A gold electrode was modified with a cysteine (Cys) ...self-assembled layer, and carboxyl-functionalized carbon nanotubes were covalently attached to Cys for the subsequent tethering of antibody against AFB1 (anti-AFB1). Topographical images of the biosensor surface were acquired by atomic force microscopy throughout the modification and assay procedure. Upon exposure to samples containing AFB1, its binding to anti-AFB1 will result in a change in electrical conductivity. The use of CNT warrants enhanced electrical properties, and the charge-transfer resistance (Rct) can be related to the concentration of AFB1. Biosensor selectivity was tested by using samples containing ochratoxin A. The electrode displays a limit of detection as low as 0.79 pg·g
−1
, and response is linear in the 0.1 to 20 pg·g
−1
concentration range. The assay was applied to the determination of AFB1 in contaminated corn flour at concentrations so low that they cannot be quantified by established ELISAs. In our perception, this method represents a viable point-of-care probe for detection of AFB1.
Graphical abstract
A gold electrode was modified with a cysteine self-assembled layer, and carboxyl-functionalized carbon nanotubes were covalently attached to cysteine for the subsequent tethering of antibody against AFB1. The assay was applied to the determination of AFB1 in contaminated corn flour.
This paper demonstrates by means of FTIR/ATR analysis that water molecules intercalate at different extents in the acyl chain region of lipid membranes in correlation with the hydration of the ...phosphate groups.
This correlation is sensible to the chain length, the presence of double bonds and the phase state of the lipid membrane.
The presence of carbonyl groups CO modifies the profile of hydration of the two regions as observed from the comparison of DMPC and 14:0 Diether PC.
The different water populations in lipid interphases would give arrangements with different free energy states that could drive the interaction of biological effectors with membranes.
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•Water intercalates in the acyl chain region of lipid membranes correlated with the hydration of the phosphate groups.•The correlation is sensible to the chain length, the presence of double bonds and the phase state of the lipid membrane.•Carbonyl groups CO modifies the profile of hydration of the two regions.•Different water populations in each condition
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Let S be a numerical semigroup. An element
is a special gap of S if
is also a numerical semigroup. If a is a positive integer, we denote by
the set of all numerical semigroups for which a is a ...special gap. We say that an element of
is
-irreducible if it cannot be expressed as the intersection of two numerical semigroups of
properly containing it. The main aim of this paper is to describe three algorithmic procedures: the first one calculates the elements of
the second one determines whether or not a numerical semigroup is
-irreducible and the third one computes all the
-irreducibles numerical semigroups.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Lysozyme (LYS) applications encompass anti-bacterial activity, analgesic, and anti-inflammatory effects. In this work, a porous framework that was based on the polymerization of pyrrole (PPy) in the ...presence of multi-functional graphene oxide/iron oxide composite (GO@Fe3O4) has been developed. Oxygen-containing and amine groups that were present in the nanocomposite were availed to assembly LYS as the molecularly imprinted polymer (MIP) template. The synthesized material (MIPPy/GO@Fe3O4) was electrodeposited on top of a gold microelectrode array. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to confirm the adequate preparation of GO@Fe3O4, and the characterization of the resulting molecularly imprinted electrochemical sensor (MIECS) was carried out by electrochemical impedance spectrometry (EIS), FT-IR analysis, and scanning electron microscopy (SEM). The impedimetric responses were analyzed mathematically by fitting to a Q(Q(RW)) equivalent circuit and quantitative determination of LYS was obtained in a linear range from 1 pg/mL to 0.1 µg/mL, presenting good precision (RSD ≈ 10%, n = 5) and low limit of detection (LOD = 0.009 pg/mL). The fabrication of this device is relatively simple, scalable, rapid, and economical, and the sensor can be used up to nine times without disintegration. The MIECS was successfully applied to the determination of LYS in fresh chicken egg white sample and in a commercial drug, resulting in a straightforward platform for the routine monitoring of LYS.
Objective
To define and characterize the progression of the spontaneous autoimmune disease that develops in mice in the absence of the leukocyte adhesion receptor P‐selectin glycoprotein ligand 1 ...(PSGL‐1).
Methods
Skin‐resident immune cells from PSGL‐1–deficient mice and C57BL/6 control mice of different ages were isolated and analyzed by flow cytometry. Biochemical parameters were analyzed in mouse serum and urine, and the presence of serum autoantibodies was investigated. Skin and internal organs were extracted, and their structure was analyzed histologically.
Results
Skin‐resident innate and adaptive immune cells from PSGL‐1−/− mice had a proinflammatory phenotype with an imbalanced T effector cell:Treg cell ratio. Sera from PSGL‐1−/− mice had circulating autoantibodies commonly detected in connective tissue–related human autoimmune diseases. Biochemical and histologic analysis of skin and internal organs revealed skin fibrosis and structural and functional abnormalities in the lungs and kidneys. Furthermore, PSGL‐1−/− mice exhibited vascular alterations, showing loss of dermal vessels, small vessel medial layer remodeling in the lungs and kidneys, and ischemic processes in the kidney that promote renal infarcts.
Conclusion
Our study demonstrates that immune system overactivation due to PSGL‐1 deficiency triggers an autoimmune syndrome with characteristics similar to systemic sclerosis, including skin fibrosis, vascular alterations, and systemic organ involvement. These results suggest that PSGL‐1 expression contributes to the maintenance of the homeostasis of the immune system and could act as a barrier for autoimmunity in mice.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Neuroinflammation contributes to neuronal degeneration in Parkinson's disease (PD). However, how brain inflammatory factors mediate the progression of neurodegeneration is still poorly understood. ...Experimental models of PD have shed light on the understanding of this phenomenon, but the exploration of inflammation-driven models is necessary to better characterize this aspect of the disorder. The use of lipopolysaccharide (LPS) to induce a neuroinflammation-mediated neuronal loss is useful to induce reliable elimination of dopaminergic neurons. Nevertheless, how this model parallels the PD-like neuroinflammation is uncertain. In the present work, we used the direct LPS injection as a model inductor to eliminate dopaminergic neurons of the substantia nigra pars compacta (SNpc) in rats and reevaluated the inflammatory reaction. High-resolution 3D histological examination revealed that, although LPS induced a reliable elimination of SNpc dopaminergic neurons, it also generated a massive inflammatory response. This inflammation-mediated injury was characterized by corralling, a damaged parenchyma occupied by a vast population of lesion-associated microglia and macrophages (LAMMs) undertaking wound compaction and scar formation, surrounded by highly reactive astrocytes. LAMMs tiled the entire lesion and engaged in long-standing phagocytic activity to resolve the injury. Additionally, modeling LPS inflammation in a cell culture system helped to understand the role of phagocytosis and cytotoxicity in the initial phases of dopaminergic degeneration and indicated that LAMM-mediated toxicity and phagocytosis coexist during LPS-mediated dopaminergic elimination. However, this type of severe inflammatory-mediated injury, and subsequent resolution appear to be different from the ageing-related PD scenario where the architectural structure of the parenchyma is mostly preserved. Thus, the necessity to explore new experimental models to properly mimic the inflammatory compound observed in PD degeneration.
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•LPS-induced mesencephalic injury causes corralling of microglia/macrophages•LPS-mediated lesion in SNpc triggers microglia/macrophages tiling and honeycomb structures•Microglia/macrophages tiling contributes to promote interactions with remnant dopaminergic neurons and debris•Corralled lesion shows high phagocytic capacity of dopaminergic remains
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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