•ACE2 are highly expressed in human small intestinal enterocytes.•2019-nCoV may have same tissue tropism such as small intestine with SARS-CoV.•The gastrointestinal tract may be an alternative route ...for 2019-nCoV.•Distribution pattern of ACE2 gene insinuates the possibility of a fecal–oral transmission for COVID-19.
The coronavirus disease 2019 (COVID-19) was first reported in Wuhan, China and rapidly spread in other countries in December 2019. The infected patients presented with fever, respiratory symptoms, sometimes with digestive and other systemic manifestations, and some progressed with a severe acute respiratory syndrome or even death. Associated digestive symptoms were frequently observed in the patients, with an unknown significance and mechanism. ACE2, as the major known functional receptor of the 2019 novel coronavirus (2019-nCoV) attracted our attention. We collected the clinical data of the 2019-nCoV-infected patients from published studies and extracted the data about the incidence of gastrointestinal symptoms. Furthermore, we used online datasets to analyze ACE2 expression in different human organs, especially in the small intestine, to explore the relationship between ACE2 expression patterns and clinical symptoms. We found that diarrhea accounted for a notable proportion of COVID-19 patients, ranging from 8.0% to 12.9%. The results reveal that ACE2 mRNA and protein are highly expressed in the small intestinal enterocytes but not in the goblet cells or intestinal immune cells. High expression of ACE2 on the surface cells in the digestive tract may lead to gastrointestinal symptoms and inflammation susceptibility. Overall, digestive symptoms were common in the COVID-19 patients. ACE2 expression on surface cells of the small intestine may mediate the invasion and amplification of the virus and activation of gastrointestinal inflammation. It is a possible mechanism of digestive symptoms in the COVID-19 patients and explains the presence of the virus in patients’ stool samples. The study also highlights the necessity of taking stool samples for suspected patients to help in early diagnosis and assessment of disease status.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A geophysical model function (GMF), which is denoted by XMOD2, is developed to retrieve sea surface wind field from X-band TerraSAR-X/TanDEM-X (TS-X/TD-X) data. In contrast to the previously ...developed XMOD1, XMOD2 consists of a nonlinear GMF, and thus, it depicts the difference between upwind and downwind of the sea surface backscatter in X-band synthetic aperture radar (SAR) imagery. By exploiting 371 collocations with in situ buoy measurements that are used as the tuning data set together with analysis wind model results, the retrieved TS-X/TD-X sea surface wind speed using XMOD2 shows a close agreement with buoy measurements with a bias of -0.32 m/s, a root-mean-square error (RMSE) of 1.44 m/s, and a scatter index (SI) of 16.0%. Further validation using an independent data set of 52 cases shows a bias of -0.17 m/s, an RMSE of 1.48 m/s, and an SI of 17.0% comparing with buoy measurements. To apply XMOD2 to TS-X/TD-X data acquired at HH polarization, we validate three X-band SAR polarization ratio models that were tuned using TS-X dual-polarization data by comparing the retrieved sea surface wind speed with buoy measurements.
Indoor detection of volatile organic compounds (VOCs) concentration is necessary due to the serious toxicity hazards even at trace level. However, physisorbents usually exhibit weak interactions ...especially in the presence of trace concentrations of VOCs, thus exhibiting poor responsive signal. Herein, we report a new flexible metal–organic framework (MOF) that exhibits interesting pore‐opening behavior after immersing in H2O. The pore‐opening phase shows significant (≈116 folds) and extremely fast (<1 minute) fluorescence enhancement after being exposed to saturated benzene vapor. The limit of detection concentration for benzene vapor can be calculated as 0.133 mg L−1. Thus this material represents the first MOF to achieve visual detection of trace benzene vapor by the naked eyes. Theoretical calculations and single‐crystal structure reveal that the special “bilateral π–π stacking” interactions between the host and guest, which facilitate electron transfer and greatly enhance the intensity of fluorescence.
A new flexible metal–organic framework (MOF) exhibits significant and sensitive fluorescence “turn‐on” behavior for benzene vapor by virtue of unique “bilateral π–π stacking” interactions, enabling visual detection of a trace level of benzene for the first time.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Magnesium isotopic compositions are reported for twenty‐four international geological reference materials including igneous, metamorphic and sedimentary rocks, as well as phlogopite and serpentine ...minerals. The long‐term reproducibility of Mg isotopic determination, based on 4‐year analyses of olivine and seawater samples, was ≤ 0.07‰ (2s) for δ26Mg and ≤ 0.05‰ (2s) for δ25Mg. Accuracy was tested by analysis of synthetic reference materials down to the quoted long‐term reproducibility. This comprehensive dataset, plus seawater data produced in the same laboratory, serves as a reference for quality assurance and inter‐laboratory comparison of high‐precision Mg isotopic data.
Les compositions isotopiques du magnésium sont fournies pour vingt‐quatre matériaux géologiques de référence internationaux, comprenant des roches ignées, métamorphiques et sédimentaires, ainsi qu'une phlogopite et des serpentines. La reproductibilité à long terme de la détermination isotopique du Mg, basée des analyses sur quatre ans d’échantillons d'olivine et d'eau de mer, était ≤ 0.07% (2s) pour δ26Mg et ≤ 0.05% (2s) pour δ25Mg. La précision a été testée par l'analyse de matériaux de référence synthétiques jusqu’à la reproductibilité à long terme indiquée. Cette base de données complète, ainsi que des données d'eau de mer produites dans le même laboratoire, servent de référence pour l'assurance qualité et la comparaison inter‐laboratoires de haute précision des données isotopiques du Mg.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
The feedback between CO2 sources and sinks through chemical weathering is one of the important reasons why Earth has maintained a habitable climate for over four billion years. The lithium (Li) ...isotopic system is a promising tracer of silicate weathering, but the mechanisms causing its isotope fractionation during weathering remain ambiguous. Here, we performed batch experiments of Li adsorption to one of the common clay minerals -kaolinite in three sets, including the time-series, pH-dependent, and concentration-control sets. Our results demonstrate that the liquid-solid Li isotope fractionation reaches up to 36‰, with up to 99% initial Li being adsorbed on kaolinite. The magnitudes of Li adsorption and isotope fractionation increase with reaction time, and reach the steady-state after ∼1000 min. The magnitude of Li isotope fractionation increases with the adsorption ratio of Li, in positive relationships with solute pH and ionic strength. At constant solute pH = 8.5 and ionic strength of 0.001 M, the adsorption ratio and isotope fractionation of Li on kaolinite reach the maximum with the lowest initial Li concentration of 2 μM. In experiments, Li is removed by kaolinite as the inner-sphere and/or outer-sphere complexes, likely followed by structural occupation as supported by incomplete desorption. We model the Li isotope fractionation in all three sets, which can be best described by Rayleigh distillation models. In summary, significant Li isotope fractionation occurs following a kinetic law in closed-systems during adsorption on kaolinite. Adsorption-driven isotope fractionation conforms to a kinetic solid-liquid isotope fractionation factor α ∼ 0.992, consistent with theoretical ion-desolvation between complexed and dissolved ions (α = 0.9925, Hofmann et al., 2012). This study reveals a vital kinetic role of clay uptake in Li isotope fractionation during chemical weathering, suggesting rapid forward adsorption reaction versus relatively slow backward reaction. The dominance of the kinetic mechanism over the equilibrium mechanism further explains field observations from rivers worldwide. Given above, the outcome of this study calls for additional attention on low-temperature kinetic Li isotope fractionation at Earth’s surface and further refinement of quantitative models using geological Li records to trace weathering and reconstruct climate.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Necroptosis plays an essential role in acute kidney injury and is mediated by receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3), and mixed lineage kinase ...domain-like pseudokinase (MLKL). A novel RIPK3 inhibitor, compound 42 (Cpd-42) alleviates the systemic inflammatory response. The current study was designed to investigate whether Cpd-42 exhibits protective effects on acute kidney injury and reveal the underlying mechanisms.
The effects of Cpd-42 were determined in vivo through cisplatin- and ischaemia/reperfusion (I/R)-induced acute kidney injury and in vitro through cisplatin- and hypoxia/re-oxygenation (H/R)-induced cell damage. Transmission electron microscopy and periodic acid-Schiff staining were used to identify renal pathology. Cellular thermal shift assay and RIPK3-knockout mouse renal tubule epithelial cells were used to explore the relationship between Cpd-42 and RIPK3. Molecular docking and site-directed mutagenesis were used to determine the binding site of RIPK3 with Cpd-42.
Cpd-42 reduced human proximal tubule epithelial cell line (HK-2) cell damage, necroptosis and inflammatory responses in vitro. Furthermore, in vivo, cisplatin- and I/R-induced acute kidney injury was alleviated by Cpd-42 treatment. Cpd-42 inhibited necroptosis by interacting with two key hydrogen bonds of RIPK3 at Thr94 and Ser146, which further blocked the phosphorylation of RIPK3 and mitigated acute kidney injury.
Acting as a novel RIPK3 inhibitor, Cpd-42 reduced kidney damage, inflammatory response and necroptosis in acute kidney injury by binding to sites Thr94 and Ser146 on RIPK3. Cpd-42 could be a promising treatment for acute kidney injury.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Efficient adsorptive separation of propylene/propane (C3H6/C3H8) is highly desired and challenging. Known strategies focus on either the thermodynamic or the kinetic mechanism. Here, we report an ...interesting reactivity of a metal–organic framework that improves thermodynamic and kinetic adsorption selectivity simultaneously. When the metal–organic framework is heated under oxygen flow, half of the soft methylene bridges of the organic ligands are selectively oxidized to form the more polar and rigid carbonyl bridges. Mixture breakthrough experiments showed drastic increase of C3H6/C3H8 selectivity from 1.5 to 15. For comparison, the C3H6/C3H8 selectivities of the best‐performing metal–organic frameworks Co‐MOF‐74 and KAUST‐7 were experimentally determined to be 6.5 and 12, respectively. Gas adsorption isotherms/kinetics, single‐crystal X‐ray diffraction, and computational simulations revealed that the oxidation gives additional guest recognition sites, which improve thermodynamic selectivity, and reduces the framework flexibility, which generate kinetic selectivity.
Tailoring with O2: When a flexible metal–organic framework is heated in a flow of oxygen, half of the organic ligands are selectively oxidized, thereby adding guest recognition sites and reducing the flexibility of the pores. As a result, the thermodynamic and kinetic selectivity for propylene/propane separation improve simultaneously.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Global soil carbon (C) stocks are expected to decline with warming, and changes in microbial processes are key to this projection. However, warming responses of critical microbial parameters such as ...carbon use efficiency (CUE) and biomass turnover (rB) are not well understood. Here, we determine these parameters using a probabilistic inversion approach that integrates a microbial‐enzyme model with 22 years of carbon cycling measurements at Harvard Forest. We find that increasing temperature reduces CUE but increases rB, and that two decades of soil warming increases the temperature sensitivities of CUE and rB. These temperature sensitivities, which are derived from decades‐long field observations, contrast with values obtained from short‐term laboratory experiments. We also show that long‐term soil C flux and pool changes in response to warming are more dependent on the temperature sensitivity of CUE than that of rB. Using the inversion‐derived parameters, we project that chronic soil warming at Harvard Forest over six decades will result in soil C gain of <1.0% on average (1st and 3rd quartiles: 3.0% loss and 10.5% gain) in the surface mineral horizon. Our results demonstrate that estimates of temperature sensitivity of microbial CUE and rB can be obtained and evaluated rigorously by integrating multidecadal datasets. This approach can potentially be applied in broader spatiotemporal scales to improve long‐term projections of soil C feedbacks to climate warming.
Model performance is substantially improved by integrating 22 years of data using a probabilistic inversion method. Warming reduces microbial carbon use efficiency (CUE) but increases microbial biomass turnover rate (rB). Two decades of soil warming increases the temperature sensitivities of CUE and rB suggesting no thermal adaptation of the microbial decomposer community.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Precise determination of the structure‐property relationship of zeolite‐based metal catalysts is critical for the development toward practical applications. However, the scarcity of real‐space ...imaging of zeolite‐based low‐atomic‐number (LAN) metal materials due to the electron‐beam sensitivity of zeolites has led to continuous debates regarding the exact LAN metal configurations. Here, a low‐damage high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) imaging technique is employed for direct visualization and determination of LAN metal (Cu) species in ZSM‐5 zeolite frameworks. The structures of the Cu species are revealed based on the microscopy evidence and also proved by the complementary spectroscopy results. The correlation between the characteristic Cu size in Cu/ZSM‐5 catalysts and their direct oxidation of methane to methanol reaction properties is unveiled. As a result, the mono‐Cu species stably anchored by Al pairs inside the zeolite channels are identified as the key structure for higher C1 oxygenates yield and methanol selectivity for direct oxidation of methane. Meanwhile, the local topological flexibility of the rigid zeolite frameworks induced by the Cu agglomeration in the channels is also revealed. This work exemplifies the combination of microscopy imaging and spectroscopy characterization serves as a complete arsenal for revealing structure‐property relationships of the supported metal‐zeolite catalysts.
A low‐damage HAADF‐STEM imaging technique is employed for direct visualization and determination of Cu species in ZSM‐5 zeolite frameworks. The structure of the Cu species are revealed based on the microscopy evidence and also proved by the complementary spectroscopy results. The mono‐Cu species stably anchored by Al pairs inside the zeolite channels are identified as the key structure for higher C1 oxygenates yield and methanol selectivity for direct oxidation of methane.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Summary
Diversity and plasticity are hallmarks of macrophages. Classically activated macrophages are considered to promote T helper type 1 responses and have strong microbicidal, pro‐inflammatory ...activity, whereas alternatively activated macrophages are supposed to be associated with promotion of tissue remodelling and responses to anti‐inflammatory reactions. Transformation of different macrophage phenotypes is reflected in their different, sometimes even opposite, roles in various diseases or inflammatory conditions. MicroRNAs (miRNAs) have emerged as critical regulators of macrophage polarization (MP). Several miRNAs are induced by Toll‐like receptors signalling in macrophages and target the 3′‐untranslated regions of mRNAs encoding key molecules involved in MP. Therefore, identification of miRNAs related to the dynamic changes of MP and understanding their functions in regulating this process are important for discussing the molecular basis of disease progression and developing novel miRNA‐targeted therapeutic strategies. Here, we review the current knowledge of the role of miRNAs in MP with relevance to immune response and inflammation.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
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