Introduction
Gut microbiota is now considered to be a hidden organ that interacts bidirectionally with cellular responses in numerous organs belonged to the immune, bone, and nervous systems. Here, ...we aimed to investigate the relationships between gut microbiota and complex diseases by utilizing multiple publicly available genome-wide association.
Materials and methods
We applied a novel microbiota-related gene set enrichment analysis approach to detect the associations between gut microbiota and complex diseases by processing genome-wide association studies (GWASs) data sets of six autoimmune diseases (including celiac disease (CeD), inflammatory bowel diseases (IBD), multiple sclerosis (MS), primary biliary cirrhosis (PBC), type 1 diabetes (T1D) and primary sclerosing cholangitis (PSC)) and osteoporosis (OP).
Results
The family
Oxalobacteraceae
and genus
Candidatus_Soleaferrea
were found to be correlated with all of the six autoimmune diseases (FDR adjusted
P
< 0.05). Moreover, we observed that the six autoimmune diseases except PBC shared 3 overlapping features (including family
Peptostreptococcaceae
, order
Gastranaerophilales
and genus
Romboutsia
). For all of the six autoimmune diseases and BMDs (LS-BMD and TB-BMD), an association signal was observed for genus
Candidatus_Soleaferrea
(FDR adjusted
P
< 0.05). Notably, FA / FN-BMD shared the maximum number of overlapping microbial features (e.g., genus
Ruminococcaceae_UCG009
,
Erysipelatoclostridium
and
Ruminococcaceae_UCG013
).
Conclusion
Our study found that part of the gut microbiota could be novel regulators of BMDs and autoimmune diseases via the effects of its metabolites and may lead to a better understanding of the role played by gut microbiota in the communication of the microbiota-skeletal/immune-gut axis.
Conspectus The continuing increase of the concentration of atmospheric CO2 has caused many environmental issues including climate change. Catalytic conversion of CO2 using thermochemical, ...electrochemical, and photochemical methods is a potential technique to decrease the CO2 concentration and simultaneously obtain value-added chemicals. Due to the high energy barrier of CO2 however, this method is still far from large-scale applications which requires high activity, selectivity, and stability. Therefore, development of efficient catalysts to convert CO2 to different products is urgent. With their well-engineered pores and chemical compositions, high surface area, elevated CO2 adsorption capability, and adjustable active sites, porous crystalline frameworks including metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) are potential materials for catalytic CO2 conversion. Here, we summarize our recent work on MOFs and COFs for thermocatalytic, electrocatalytic, and photocatalytic CO2 conversion and describe the structure–activity relationships that could guide the design of effective catalysts. The first section of this paper describes imidazolium-functionalized porous MOFs, including porous liquid and cationic MOFs with nucleophilic halogen ions, which can promote thermocatalytically CO2 cycloaddition reaction with epoxides toward cyclic carbonates at one bar pressure. A porous liquid MOF takes on the role of a CO2 reservoir to tackle the low local CO2 concentrations in gas–liquid–solid heterogeneous reactions. Imidazolium-functionalized MOFs with halogen ions for CO2 cycloaddition could avoid the use of cocatalysts, and this leads to milder and more facile experimental conditions and separation processes. In a section dealing with the electrocatalytic CO2 reduction reaction (CO2RR), we developed a series of conductive porous framework materials with fast electron transmission capabilities, which afford high current densities and outperform the traditional MOF and COF catalysts that have been reported. The intrinsically conductive two-dimensional 2D MOFs and COFs nanosheets based on the fully π-conjugated phthalocyanine motif with excellent electron transport capability were prepared, and strong electron transporters were also integrated into metalloporphyrin-based COFs for CO2RR. Cu2O quantum dots and Cu nanoparticles (NPs) can be uniformly dispersed on porous conductive MOFs/COFs to afford synergistic and/or tandem electrocatalysts, which can achieve highly selective production of CH4 or C2H4 in CO2RR. A third section describes our efforts to facilitate electron–hole separation in CO2 photocatalysis. Our focus is on regulation of coordination spheres in MOFs, fabrication of the architecture of MOF heterojunctions, and engineering MOF films to facilitate photocatalytic CO2 reduction. Finally, we discuss several problems associated with the studies of MOFs and COFs for CO2 conversion and consider some prospects of the fabrication of effective porous frameworks for CO2 adsorption and conversion.
Graphene‐reinforced polymer composites with high thermal conductivity show attractive prospects as thermal transfer materials in many applications such as intelligent robotic skin. However, for the ...most reported composites, precise control of the thermal conductivity is not easily achieved, and the improvement efficiency is usually low. To effectively control the 3D thermal conductivity of graphene‐reinforced polymer nanocomposites, a hyperelastic double‐continuous network of graphene and sponge is developed. The structure (orientation, density) and thermal conductivity (in‐plane, cross‐plane) of the resulting composites can be effectively controlled by adjusting the preparation and deformation parameters (unidirectional, multidirectional) of the network. Based on the experimental and theoretical simulation results, the thermal conduction mechanism is summarized as a two‐stage transmission of phonons. The in‐plane thermal conductivity increases from 0.175 to 1.68 W m−1 K−1 when the directional compression ratio increases from 0% to 95%, and the corresponding enhancement efficiency exceeds 300. The 3D thermal conductivity reaches a maximum of 2.19 W m−1 K−1 when the compression ratio is 70% in three directions, and the graphene content is 4.82 wt%. Moreover, the thermal conduction network can be largely prepared by power‐driven roller equipment, making the composite an ideal candidate for sensitive robotic skin for temperature detection.
A hyperelastic double‐continuous network of graphene and sponge is developed. Polymer nanocomposites are obtained by impregnating resin into the deformed network. The structure (orientation, density) and thermal conductivity (in‐plane, cross‐plane) of the resulting composites can be effectively controlled by adjusting the preparation and deformation parameters (compression ratio and directions) of the network.
Developing efficient bifunctional electrocatalysts for overall water splitting in acidic conditions is the essential step for proton exchange membrane water electrolyzers (PEMWEs). We first report ...the synthesis of core–shell structure nanoparticles (NPs) with an Au core and an AuIr2 alloy shell (Au@AuIr2). Au@AuIr2 displayed 4.6 (5.6) times higher intrinsic (mass) activity toward the oxygen evolution reaction (OER) than a commercial Ir catalyst. Furthermore, it showed hydrogen evolution reaction (HER) catalytic properties comparable to those of commercial Pt/C. Significantly, when Au@AuIr2 was used as both the anode and cathode catalyst, the overall water splitting cell achieved 10 mA/cm2 with a low cell voltage of 1.55 V and maintained this activity for more than 40 h, which greatly outperformed the commercial couples (Ir/C||Pt/C, 1.63 V, activity decreased within minutes) and is among the most efficient bifunctional catalysts reported. Theoretical calculations coupled with X-ray-based structural analyses suggest that partially oxidized surfaces originating from the electronic interaction between Au and Ir provide a balance for different intermediates binding and realize significantly enhanced OER performance.
The low structural stability of hydrogen‐bonded organic frameworks (HOFs) is a thorny issue retarding the development of HOFs. A rational design approach is now proposed for construction of a stable ...HOF. The resultant HOF (PFC‐1) exhibits high surface area of 2122 m2 g−1 and excellent chemical stability (intact in concentrated HCl for at least 117 days). A new method of acid‐assisted crystalline redemption is used to readily cure the thermal damage to PFC‐1. With periodic integration of photoactive pyrene in the robust framework, PFC‐1 can efficiently encapsulate Doxorubicin (Doxo) for synergistic chemo‐photodynamic therapy, showing comparable therapeutic efficacy with the commercial Doxo yet considerably lower cytotoxicity. This work demonstrates the notorious stability issue of HOFs can be properly addressed through rational design, paving a way to develop robust HOFs and offering promising application perspectives.
An ultra‐robust hydrogen‐bonded organic framework with high BET surface area and acid‐assisted crystalline recovery was developed through several rational design strategies. With periodic integration of photoactive pyrene in the framework, this material can efficiently encapsulate the drug doxorubicin for synergistic chemo‐photodynamic therapy, showing low cytotoxicity and prominent therapeutic efficacy.
•We reviewed the application of MOF materials in removal of Hg2+ ions.•We described the advantages of MOF membrane in removal of Hg2+ ions.•We propose the current problems faced by Hg2+ ions ...treatment and future solutions.
Mercury pollution of water has caused serious health problems in humans. Therefore, reducing the mercury content into the drinking water standard is currently a priority measure. As a kind of porous frame materials with adjustable structure and easy to design and synthesize, metal–organic frameworks (MOFs) materials have attracted widespread attention. Their large specific surface area and adjustable pores make MOFs an excellent platform for removing mercury metals from water. In this review, we discussed the mercury removal performance of functionalized MOF powder materials, including sulfur-functionalized MOF, nitrogen-functionalized MOF, nitrogen-sulfur co-functionalized MOF, MOF composites and MOFs-derived materials. Compared to MOF powder materials, MOF membranes can easily recycle and effectively avoid secondary pollution. Therefore, we also reviewed nanofiber MOF membranes and polymer-supported MOF membranes. At the same time, in order to further explore the potential of MOF materials in heavy metal adsorption, we also introduced the current problems and challenges faced by MOF materials in detail, and proposed future research directions and difficulties to be overcome. We will hope that the review may provide more researchers with a more comprehensive, intuitive, clear cognition.
Polymer electrolyte membrane fuel cells (PEMFCs) feature high energy densities, low operating temperatures, and low environmental impact, which make them a promising technology for power ...applications. As a key component of PEMFCs, Pt‐based catalysts are still under widespread investigation and have shown exciting performance; however, to move towards their successful commercialization, focusing solely on their catalytic activity is not sufficient. Instead, more effort is required to improve their stability and to decrease costs. Herein, we provide a comprehensive review of current research activities that have concentrated on how to stabilize the Pt‐based catalysts. We devote the most attention to the structure‐optimization of the Pt‐based catalysts and the development of advanced supports. The feasible strategies for structure optimization are subdivided into three groups: 1) dimension effects; 2) electronic and bifunctional effects; and 3) steric effects. Then, we discuss the techniques that have been developed for improving carbon black and for generating various types of carbon‐free supports and composites supports (e.g., graphite, carbon nanotubes, new‐type oxides and nitrides, and macromolecules). An outlook on the future trends and developments in this area is also provided at the end of the review.
When platinum meets polymer: Pt‐based catalysts have reached exciting performance targets towards their use in polymer electrolyte membrane fuel cells. However, moving towards their commercialization requires more efforts to improve their stability and to decrease costs. This review highlights the current research activities that have been devoted to stabilizing these Pt‐based catalysts.
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•Synthesis of ZnG@ZIF-8 composite using the ZnG as a single metal source.•The ZnG@ZIF-8 composite enhanced sustainability of the inhibitors.•The ZnG@ZIF-8/EP coatings displayed ...excellent corrosion resistance.
The unique porous characteristic of metal-organic frameworks (MOFs) has been attracting significant attention for gas storage, catalysis and drug delivery. However, the studies regarding loading inhibitors into MOFs for metallic anti-corrosion applications are scarcely reported. Herein, a strategy based on encapsulating corrosion inhibitors into MOFs matrix has been developed, and their corrosion process and mechanism have been fully studied. Specifically, an environmentally friendly green corrosion inhibitor, zinc gluconate (ZnG), was selected as a metal resource for the preparation of ZIF-8 and then inherently intercalated into the porous ZIF-8. Various characterizations were carried out to confirm that zinc gluconate was successfully loaded into the ZIF-8 matrix. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves show the evidence that the prepared ZnG@ZIF-8/EP coatings display good metallic anti-corrosion performances. The probably protecting mechanism of ZnG@ZIF/EP coatings for magnesium alloy surface was thoroughly discussed.
A significant role of MOFs as heterogeneous photocatalysts in enabling organic transformations.
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•Light harvesting Ru-polypyridyl complexes were incorporated into a semiconductor-like ...metal-organic framework (MIL-125).•Disclosing photoinduced electron transfer among photocatalysis.•The prepared Ru(bpy)3@MIL-125 exhibited good recyclability during reaction.
Visible-light-driven selective photocatalytic organic synthesis has recently become a topic of great interest due to its environmental friendliness and sustainability. It is demanding for photocatalysis to utilize the wider range of light, such as visible light, and its performance is often plagued by the sluggish separation of photogenerated charge carriers. An approach is now reported to address these issues by incorporating light harvesting RuII-polypyridyl complexes into a semiconductor-type metal-organic framework (MIL-125). Delightedly, the obtained Ru(bpy)3@MIL-125 photocatalyst presents a remarkably stable and high photoactivity toward the selective oxidative coupling of amines under ambient air with visible light irradiation (λ > 440 nm). The mechanistic investigation unveiled that both effectively photoexcited electrons transfer from Ru(bpy)3Cl2 to MIL-125 and the interaction of CH bonds with superoxide radical (O2·−) play a critical role in photo-catalyzing selective aerobic oxidative coupling of amines. This work highlights a significant role of MOFs as heterogeneous photocatalysts in photocatalytic organic transformations.
A robust, highly water stable (up to 3 weeks), microporous MOF, Zn8(O)2(CDDB)6(DMF)4(H2O) {where CDDB = 4,4'-(9-H carbazole-3,6-diyl)dibenzoic acid}, was synthesized based on an open N-H site by a ...solvothermal process and exhibited an outstanding loading capacity (around 53.3 wt%) and satisfactory release capability (64.9% and 81.9%) for 5-fluorouracil, constituting a negligible cytotoxicity effect.
