The Ni3S2 nanoparticles with the diameters ranging from 10 to 80 nm are grown on the backbone of conductive multiwalled carbon nanotubes (MWCNTs) using a glucose-assisted hydrothermal method. It is ...found that the Ni3S2 nanoparticles deposited on MWCNTs disassemble into smaller components after the composite electrode is activated by the consecutive cyclic voltammetry scan in a 2 M KOH solution. Therefore, the active surface area of the Ni3S2 nanoparticles is increased, which further enhances the capacitive performance of the composite electrode. Because the synergistic effect of the Ni3S2 nanoparticles and MWCNTs on the capacitive performance of the composite electrode is pronounced, the composite electrode shows a high specific capacitance of 800 F/g and great cycling stability at a current density of 3.2 A/g. To examine the capacitive performance of the composite electrode in a full-cell configuration, an asymmetric supercapacitor device was fabricated by using the composite of Ni3S2 and MWCNTs as the cathode and activated carbon as the anode. The fabricated device can be operated reversibly between 0 and 1.6 V, and obtain a high specific capacitance of 55.8 F/g at 1 A/g, which delivers a maximum energy density of 19.8 Wh/kg at a power density of 798 W/kg. Furthermore, the asymmetric supercapacitor shows great stability based on the fact that the device retains 90% of its initial capacitance after a consecutive 5000 cycles of galvanostatic charge–discharge performed at a current density of 4 A/g.
Maintaining lipid asymmetry across membrane leaflets is critical for functions like vesicular traffic and organelle homeostasis. However, a lack of molecular‐level understanding of the mechanisms ...underlying membrane fission and fusion processes in synthetic systems precludes their development as artificial analogs. Here, we report asymmetry induction of a bilayer membrane formed by an extended π‐conjugated molecule with oxyalkylene side chains bearing terminal tertiary amine moieties (BA1) in water. Autogenous protonation of the tertiary amines in the periphery of the bilayer by water induces anisotropic curvature, resulting in membrane fission to form vesicles and can be monitored using time‐dependent spectroscopy and microscopy. Interestingly, upon loss of the induced asymmetry by extensive protonation using an organic acid restored bilayer membrane. The mechanism leading to the compositional asymmetry in the leaflet and curvature induction in the membrane is validated by density functional theory (DFT) calculations. Studies extended to control molecules having changes in hydrophilic (BA2) and hydrophobic (BA3) segments provide insight into the delicate nature of molecular scale interactions in the dynamic transformation of supramolecular structures. The synergic effect of hydrophobic interaction and the hydrated state of BA1 aggregates provide dynamicity and unusual stability. Our study unveils mechanistic insight into the dynamic transformation of bilayer membranes into vesicles.
Spontaneous curvature induction in an artificial supramolecular bilayer membrane and its transformation into vesicles in pure water is demonstrated. Compositional asymmetry resulting from the autogenous protonation of amines led to the formation of an asymmetric membrane and curvature induction. The stability provided by the hydrophobic interaction and the hydrated state of the supramolecular structure in water appears to be critical in the dynamic morphological transformations.
A new class of ternary heterostructures consisting of a reduced graphene oxide, molybdenum disulfide, and tungsten disulfide (rGO‐MoS2‐WS2) is prepared through a simple chemical method. According to ...Raman and X‐ray photoelectron spectroscopy, a MoS2/WS2 heterostructure is uniformly formed on the conductive rGO support. Furthermore, rGO‐MoS2‐WS2 possesses s large surface area of 109 m2 g−1 and a hierarchical pore architecture. When serving as the electrode for supercapacitors, rGO‐MoS2‐WS2 exhibits pseudocapacitive behavior in a KOH solution. It is found that rGO‐MoS2‐WS2 displays a specific capacitance (Cs) of 365 F g−1 at 1 A g−1, which is much higher than those of single TMD (MoS2 or WS2)‐based composites. The enhanced electrochemical performance of rGO‐MoS2‐WS2 is attributed to the lower internal resistance through heterostructure formation, the wide range of TMD oxidation states, and uniform distribution of the few‐layered TMD nanosheets on the rGO surface. Furthermore, the optimal loading amount of MoS2/WS2 heterostructure in the composite is investigated. To demonstrate its practical application, rGO‐MoS2‐WS2 is used as a positive electrode for an asymmetric supercapacitor (ASC). The maximum energy density of the ASC device is 15 Wh kg−1 at a power density of 373 W kg−1. Furthermore, the device remains approximately 70 % of the initial Cs value after 3000 cycles, which shows the excellent cycling stability.
Positive note: A new class of ternary heterostructures consisting of a reduced graphene oxide, MoS2, and WS2 is prepared through a simple chemical method. This composite is used as a positive electrode for an asymmetric supercapacitor, which shows a maximum energy density of 15 Wh kg−1 at a power density of 373 W kg−1.
Display omitted
•Active 1T-MoS2 nanosheets are covalently functionalized with n-butyl chains (~4%).•Introduction of n-butyl chains increased the interlayer spacing to 13.8 Å from ...~9 Å.•Functionalization and solvent enrichment process improved the stability of 1T-MoS2.•en-Bu-1T-MoS2 showed superior performance in clean energy (HER & DSSC) applications.
The selective enrichment of a highly active form/phase of material is essential for the development of potential candidates for specific applications. Herein, we demonstrate the first example of the covalent functionalization of a highly active 1T phase of outstanding 2D material, such as MoS2, and its enrichment (>94%) using a solvent extraction technique. Covalent functionalization stabilizes the metastable 1T phase with increased interlayer distance, which makes it a more suitable candidate for energy applications. The enriched functionalized 1T-MoS2 with n-butyl groups (en-Bu-1T-MoS2) shows a lower overpotential of 169 mV (vs. Reversible Hydrogen Electrode, RHE) with the loading mass of 0.9 mg cm−2 toward the hydrogen evolution reaction (HER). The continuous HER of en-Bu-1T-MoS2-based electrode for >200 h showed only <11% increment in the overpotential of HER, which suggests the ultra-long term stability of en-Bu-1T-MoS2 compared to the covalently functionalized 1T-MoS2-based HER electrocatalysts reported thus far. Interestingly, the semi-transparent en-Bu-1T-MoS2 film also served as an excellent counter electrode for dye-sensitized solar cells (DSSCs) with the higher power conversion efficiency (PCE) of 9.11% and 82% of PCE retention even after 200 h. The unprecedented method presented in this work is a unique example, which shows the possibility of improving material properties with the help of a novel approach.
Obesity is associated with low-grade chronic inflammation and intestinal dysbiosis. Ganoderma lucidum is a medicinal mushroom used in traditional Chinese medicine with putative anti-diabetic effects. ...Here, we show that a water extract of Ganoderma lucidum mycelium (WEGL) reduces body weight, inflammation and insulin resistance in mice fed a high-fat diet (HFD). Our data indicate that WEGL not only reverses HFD-induced gut dysbiosis-as indicated by the decreased Firmicutes-to-Bacteroidetes ratios and endotoxin-bearing Proteobacteria levels-but also maintains intestinal barrier integrity and reduces metabolic endotoxemia. The anti-obesity and microbiota-modulating effects are transmissible via horizontal faeces transfer from WEGL-treated mice to HFD-fed mice. We further show that high molecular weight polysaccharides (>300 kDa) isolated from the WEGL extract produce similar anti-obesity and microbiota-modulating effects. Our results indicate that G. lucidum and its high molecular weight polysaccharides may be used as prebiotic agents to prevent gut dysbiosis and obesity-related metabolic disorders in obese individuals.
CNT@NiSe/SS serves as a free-standing electrode for both supercapacitors and overall water splitting. The HSC exhibits high energy density of 32.1 Wh kg−1 at a power density of 823 W kg−1. ...CNT@NiSe/SS shows excellent HER and OER activities with the lowest overpotential of 174 mV at 10 mA cm−2 and 267 mV at 50 mA cm−2, respectively. The electrolyzer requires 1.71 V to achieve 10 mA cm−2 and shows a negligible increment in potential after 24 h of continuous operation.
Display omitted
•CNT@NiSe/SS serves as the free-standing electrode for bothsupercapacitorsand overallwater splitting.•The HSC exhibits high energy density of 32.1 Wh kg−1 at the power density of 823 W kg−1.•CNT@NiSe/SS shows the high HER and OER activities with η10 = 174 mV and η50 = 267 mV.•The electrolyzer requires 1.71 V to achieve 10 mA cm−2 and shows the negligible increment in potential after 24 h.
NiSe nanoparticles are electrodeposited over a forest of carbon nanotubes (CNTs) to form an intertwined and porous network. The assynthesized composite (denoted as CNT@NiSe/SS) is used as a free-standing and multifunctional electrode for bothsupercapacitorsand overallwater splitting applications. For a supercapacitor application, CNT@NiSe/SS exhibits higher specific capacity and improved rate capability compared with individual NiSe and CNTs. A hybrid supercapacitor device consisting of battery-like CNT@NiSe/SS and EDLC-like graphene delivers a maximum energy density of 32.1 Wh kg−1 at a power density of 823 W kg−1 and has excellent stability after a floating test of 50 h. On the other hand, CNT@NiSe/SS also serves as a bifunctional electrocatalyst with high activity for overall water splitting. The CNT@NiSe/SS electrode displays excellent hydrogen and oxygen evolution reaction performance with the lowest overpotential of 174 mV at 10 mA cm−2 and 267 mV at 50 mA cm−2, respectively. The symmetrical two-electrode system requires an operating potential of 1.71 V to achieve a current density of 10 mA cm−2. Furthermore, this electrolyzer shows a negligible increment in potential after 24 hof continuouswater splitting. The outstanding performances of CNT@NiSe/SS can be attributed to the synergistic effect of NiSe and CNTs.
Display omitted
•The stability and capacitance of VOx-3DG are improved by using VOSO4/KCl electrolyte.•VOSO4 plays a dual role during the GCD process of the composite electrode.•As an electroplating ...solution, VOSO4 helps the V2O5 electrodeposition over the electrode surface.•As a redox active electrolyte, VOSO4 provides the additional capacitive contribution.•ASC delivers 16 Wh kg−1 at 200 W kg−1 and its capacitance retention is 88% after 10,000 cycles.
The composites consisting of vanadium oxide nanoribbons and three-dimensional graphene (VOx-3DG) are synthesized using the hydrothermal method and they are employed as binder-free cathode for supercapacitors. Although VOx-3DG exhibits the high capacitance of 325 mF cm−2 at 1 mA cm−2 in 0.5 M KCl electrolyte, its cycling stability is very poor. Therefore, an innovative and effective method is proposed to improve the stability and capacitance of VOx-3DG by adding VOSO4 into KCl electrolyte. The function of the VOSO4 additive is twofold: (i) it facilitates electrodeposition of vanadium oxide nanoneedles over the electrode surface to keep the nanoribbon structure intact during charge-discharge process, and (ii) it serves as a redox-active electrolyte to provide the additional capacitance contribution via its specific V4+/V5+ conversion. Due to the aforementioned synergistic effects, VOx-3DG electrode after 500 cycles shows the capacitance of 8072 mF cm−2 at 2 mA cm−2, being 7.2 times higher than the initial value. A series of studies are performed to optimize the overall electrode performance. For example, the loading amount of electrodeposited vanadium oxide and electrode capacitance are profoundly modulated by several parameters such as the concentration of VOSO4, the concentration and pH value of the buffer solution. Finally, the asymmetric supercapacitor with VOSO4/KCl shows the increase in energy density by 33% compared with the one with pure KCl electrolyte. Furthermore, the former delivers a maximum energy density of 16 Wh kg−1 at a power density of 200 W kg−1 and exhibits 88% capacitance retention after 10,000 cycles.
Microscopic colitis (MC) is a chronic inflammatory disease of colon with clinical presentations of chronic, watery, nonbloody diarrhea, and normal or almost normal endoscopic findings. Confirmation ...of a diagnosis of MC requires microscopic examination on colon biopsy to identify characteristic morphological features, in which 2 main subtypes of MC, lymphocytic colitis (LC) and collagenous colitis (CC), have been described. Although the pathogenesis of MC is still unclear, studies have revealed associations of MC with many risk factors and other diseases such as celiac disease, inflammatory bowel disease, and medication use. Meanwhile, variants of MC, MC incomplete, or MC-like changes in other conditions are still diagnostic dilemmas for pathologists. The goal of this paper is to systemically introduce the clinicopathologic features of MC and focus on unusual features of MC and its associations with other conditions.
•Diagnosis of two main subtypes of microscopic colitis (MC): lymphocytic colitis (LC) and collagenous colitis (CC), requires microscopic examination.•LC is characterized by increased lamina propria inflammation and intraepithelial lymphocytosis, and CC has similar findings but with thickened subepithelial collagen band.•Diagnostic criteria for LC and CC have been well established, but some variants including MC incomplete are still underrecognized.•MC are frequently associated other conditions such as celiac disease and medications.
Dysbiosis of gut microbiota is closely related to occurrence of many important chronic inflammations-related diseases. So far the traditionally prescribed prebiotics and probiotics do not show ...significant impact on amelioration of these diseases in general. Thus the development of next generation prebiotics and probiotics designed to target specific diseases is urgently needed. In this review, we first make a brief introduction on current understandings of normal gut microbiota, microbiome, and their roles in homeostasis of mucosal immunity and gut integrity. Then, under the situation of microbiota dysbiosis, development of chronic inflammations in the intestine occurs, leading to leaky gut situation and systematic chronic inflammation in the host. These subsequently resulted in development of many important diseases such as obesity, type 2 diabetes mellitus, liver inflammations, and other diseases such as colorectal cancer (CRC), obesity-induced chronic kidney disease (CKD), the compromised lung immunity, and some on brain/neuro disorders. The strategy used to optimally implant the effective prebiotics, probiotics and the derived postbiotics for amelioration of the diseases is presented. While the effectiveness of these agents seems promising, additional studies are needed to establish recommendations for most clinical settings.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The application of the composite of Ni3S2 nanoparticles and 3D graphene as a novel cathode material for supercapacitors is systematically investigated in this study. It is found that the electrode ...capacitance increases by up to 111% after the composite electrode is activated by the consecutive cyclic voltammetry scanning in 1 M KOH. Due to the synergistic effect, the capacitance and the diffusion coefficient of electrolyte ions of the activated composite electrode are ca. 3.7 and 6.5 times higher than those of the Ni3S2 electrode, respectively. Furthermore, the activated composite electrode exhibits an ultrahigh specific capacitance of 3296 F/g and great cycling stability at a current density of 16 A/g. To obtain the reasonable matching of cathode/anode electrodes, the composite of Fe(3)O(4) nanoparticles and chemically reduced graphene oxide (Fe(3)O(4)/rGO) is synthesized as the anode material. The Fe(3)O(4)/rGO electrode exhibits the specific capacitance of 661 F/g at 1 A/g and excellent rate capability. More importantly, an asymmetric supercapacitor fabricated by two different composite electrodes can be operated reversibly between 0 and 1.6 V and obtain a high specific capacitance of 233 F/g at 5 mV/s, which delivers a maximum energy density of 82.5 Wh/kg at a power density of 930 W/kg.
PDF
