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•The microbial ecosystem of Chinese liquor cellar was studied as a whole.•Significantly distinctive microbial communities were identified in jiupei and pit mud.•The metabolic ...contribution in organic acid synthesis of jiupei and pit mud microbiota was explored.•Acetate and lactate accumulated in jiupei were further converted to butyrate and hexanoate by pit mud microbiota.•Synergistic cooperation within jiupei and pit mud microbiota drives baijiu’s typical flavor formation.
Mud cellars have long been used as anaerobic bioreactors for the fermentation of Chinese strong-flavor Baijiu, where starchy raw materials (mainly sorghum) are metabolized to ethanol and various flavor compounds by multi-species microorganisms. Jiupei (fermented grains) and pit mud are two spatially linked microbial habitats in the mud cellar, yet their metabolic division of labor remains unclear. Here, we investigated the changes in environmental variables (e.g., temperature, oxygen, pH), key metabolites (e.g., ethanol, organic acids) and microbial communities in jiupei and pit mud during fermentation. Jiupei (low pH, high ethanol) and pit mud (neutral pH) provided two habitats with distinctly different environmental conditions for microbial growth. Lactic acid accumulated in jiupei, while butyric and hexanoic acids were mainly produced by microbes inhabiting the pit mud. Biomass analysis using quantitative real-time PCR showed that bacteria dominated the microbial consortia during fermentation, moreover cluster and principal coordinate analysis (PCoA) analysis showed that the bacterial communities of jiupei and pit mud were significantly divergent. The bacterial community diversity of jiupei decreased significantly during the fermentation process, and was relatively stable in pit mud. Lactobacillus dominated the jiupei bacterial community, and its relative abundance reached 98.0% at the end of fermentation. Clostridia (relative abundance: 42.9–85.5%) was the most abundant bacteria in pit mud, mainly distributed in the genus Hydrogenispora (5.3–68.4%). Fungal communities of jiupei and pit mud showed a similar succession pattern, and Kazachstania, Aspergillus and Thermoascus were the predominant genera. PICRUSt analysis demonstrated that enzymes participating in the biosynthesis of acetic and lactic acid were mainly enriched in jiupei samples, while the bacterial community in the pit mud displayed greater potential for butyric and hexanoic acid synthesis. Assays from an in vitro simulated fermentation further validated the roles of jiupei microbiota in acetic and lactic acid production, and these acids were subsequently metabolized to butyric and hexanoic acid by the pit mud microbiota. This work has demonstrated the synergistic cooperation between the microbial communities of jiupei and pit mud for the representative flavor formation of strong-flavor Baijiu.
Classical amino-functionalized Fe-terephthalate metal–organic framework NH2-MIL-53(Fe) and its parent framework MIL-53(Fe) were prepared via simple hydrothermal methods. The catalytic performaces ...of these two Fe-MOFs were explored for the selective oxidation of H2S. The physicochemical properties of the fresh and used Fe-MOFs catalysts were investigated by XRD, BET, SEM, FT-IR, CO2-TPD, and XPS techniques. It was found that the introduction of amino groups reduces the activation energies for H2S oxidation and endows this catalyst surface with moderate basic sites. As a result, the NH2-MIL-53(Fe) catalyst displays high H2S conversion and near 100% S selectivity in the temperature range of 130–160 °C, outperforming commercial Fe2O3 and activated carbon. Moreover, a plausible reaction route for H2S selective oxidation over NH2-MIL-53(Fe) is proposed. This work opens up the possibility of utilizing MOFs as efficient catalyst for desulfuration reactions.
In the early February, 2020, we called up an experts’ committee with more than 30 Chinese experts from 11 national medical academic organizations to formulate the first edition of consensus statement ...on diagnosis, treatment and prevention of coronavirus disease 2019 (COVID-19) in children, which has been published in this journal. With accumulated experiences in the diagnosis and treatment of COVID-19 in children, we have updated the consensus statement and released the second edition recently. The current version in English is a condensed version of the second edition of consensus statement on diagnosis, treatment and prevention of COVID-19 in children. In the current version, diagnosis and treatement criteria have been optimized, and early identification of severe and critical cases is highlighted. The early warning indicators for severe pediatric cases have been summarized which is utmost important for clinical practice. This version of experts consensus will be valuable for better prevention, diagnosis and treatment of COVID-19 in children worldwide.
Chemodynamic therapy (CDT) utilizes iron‐initiated Fenton chemistry to destroy tumor cells by converting endogenous H2O2 into the highly toxic hydroxyl radical (.OH). There is a paucity of ...Fenton‐like metal‐based CDT agents. Intracellular glutathione (GSH) with .OH scavenging ability greatly reduces CDT efficacy. A self‐reinforcing CDT nanoagent based on MnO2 is reported that has both Fenton‐like Mn2+ delivery and GSH depletion properties. In the presence of HCO3−, which is abundant in the physiological medium, Mn2+ exerts Fenton‐like activity to generate .OH from H2O2. Upon uptake of MnO2‐coated mesoporous silica nanoparticles (MS@MnO2 NPs) by cancer cells, the MnO2 shell undergoes a redox reaction with GSH to form glutathione disulfide and Mn2+, resulting in GSH depletion‐enhanced CDT. This, together with the GSH‐activated MRI contrast effect and dissociation of MnO2, allows MS@MnO2 NPs to achieve MRI‐monitored chemo–chemodynamic combination therapy.
Self‐reinforcing weapon: The Fenton‐like Mn2+ delivery and glutathione (GSH) depletion abilities of MnO2 allow it to exert enhanced chemodynamic efficacy in cancer treatment. An activatable theranostic platform based on multifunctional MnO2‐coated mesoporous silica nanoparticles (MS@MnO2 NPs) has been developed for MRI‐monitored combination chemotherapy and chemodynamic therapy (CDT). ADS=antioxidant defense system.
Activating PtSe2 monolayer for Hydrogen Evolution Reaction by defect engineering and Pd doping.
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•Pd dopant is introduced to active the basal plane for HER.•Pd doping reduces the band ...gap and enhances the catalytic ability.•Pd dopant and vacancies improve the catalytic activities comparable to that of Pt.•Band-center model is applied to better understand the difference in HER activities.
Platinum diselenide (PtSe2) has been successfully fabricated with a hope of catalytic applications. However, the active sites of pristine PtSe2 are only located at the edges while the sites in basal plane are largely inactive. To change such situation, in this study we introduce Pd dopant and vacancies to activate the basal plane for hydrogen evolution reaction (HER). Based on systematic density functional theory calculations, we find that Pd doping reduces the band gap and enhances the catalytic ability, and the divacancy sites (VSe2 and VPt2) in pristine PtSe2 monolayer and the monovacancy sites (VSe, VPd) as well as the divacancy sites (VPt2, VPdPt) in PdPtSe4 monolayer significantly improve the catalytic activities comparable to that of Pt(111). A band-center model is applied to better understand the difference in HER activities, where the chemical bond energies of H (ΔG1) show an approximately linear relationship with the energy of d/p level of Pt/Se. The strategy proposed here would be applicable to other two-dimensional materials.
Abstract
Nationwide prospective surveillance of all-age patients with acute respiratory infections was conducted in China between 2009‒2019. Here we report the etiological and epidemiological ...features of the 231,107 eligible patients enrolled in this analysis. Children <5 years old and school-age children have the highest viral positivity rate (46.9%) and bacterial positivity rate (30.9%). Influenza virus, respiratory syncytial virus and human rhinovirus are the three leading viral pathogens with proportions of 28.5%, 16.8% and 16.7%, and
Streptococcus pneumoniae
,
Mycoplasma pneumoniae
and
Klebsiella pneumoniae
are the three leading bacterial pathogens (29.9%, 18.6% and 15.8%). Negative interactions between viruses and positive interactions between viral and bacterial pathogens are common. A Join-Point analysis reveals the age-specific positivity rate and how this varied for individual pathogens. These data indicate that differential priorities for diagnosis, prevention and control should be highlighted in terms of acute respiratory tract infection patients’ demography, geographic locations and season of illness in China.
Chronic pancreatitis (CP) is characterized by persistent inflammation of the pancreas that results in progressive loss of the endocrine and exocrine compartment owing to atrophy and/or replacement ...with fibrotic tissue. Currently, the clinical therapeutic scheme of CP is mainly symptomatic treatment including pancreatic enzyme replacement, glycaemic control and nutritional support therapy, lacking of specific therapeutic drugs for prevention and suppression of inflammation and fibrosis aggravating in CP. Here, we investigated the effect of isoliquiritigenin (ILG), a chalcone‐type dietary compound derived from licorice, on pancreatic fibrosis and inflammation in a model of caerulein‐induced murine CP, and the results indicated that ILG notably alleviated pancreatic fibrosis and infiltration of macrophages. Further in vitro studies in human pancreatic stellate cells (hPSCs) showed that ILG exerted significant inhibition on the proliferation and activation of hPSCs, which may be due to negative regulation of the ERK1/2 and JNK1/2 activities. Moreover, ILG significantly restrained the M1 polarization of macrophages (RAW 264.7) via attenuation of the NF‐κB signalling pathway, whereas the M2 polarization was hardly affected. These findings indicated that ILG might be a potential anti‐inflammatory and anti‐fibrotic therapeutic agent for CP.
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•Aged Baijiu was rich in acids, long-chain ethyl esters, pyrazines and terpenes.•More even composition was driven by attaining equilibrium state of esterification.•Evenness index and ...reaction quotient (Qc) of esterification are age-indicative.•41 age-related features were selected out using 5 ranking algorithms and 3 models.•Model using 41 key-features as input could accurately predict age group of Baijiu.
The aged Chinese liquor, Baijiu, is highly valued for its superior organoleptic qualities. However, since age-authentication method and aging-mechanism elucidation of Baijiu is still in the exploratory stage, high-quality aged Baijiu is often replaced by lower-quality, less-aged product with fraudulent mislabeling. Authentic high-quality strong-flavor Baijiu was analyzed by gas chromatography-mass spectrometry. Total esters decreased with aging, while acids, alcohols, aldehydes, ketones, terpenes, pyrazines increased. Although concentrations of partial compounds showed non-monotonic profiling during aging, a close positive linear correlation (R2 = 0.7012) of Baijiu Evenness index (0.55–0.59) with aging time was observed, indicating a more balanced composition in aged Baijiu. The reaction quotient (Qc) of each esterification, calculated by the corresponding reactant and product concentration, approached to the corresponding thermodynamic equilibrium constant Kc. This result demonstrated that the spontaneous transformation driven by thermodynamics explained part of the aging compositional profiling. Furthermore, an aging-related feature selection and an age-authentication method were established based on three models combined with five ranking algorithms. Forty-one key features, including thirty-six compound concentrations, four esterification Qc values and the Evenness index were selected out. The age-authentication based on neural network using forty-one input features accurately predicted the age group of Baijiu samples (F1 = 100 %). These findings have deepened understanding of the Baijiu aging mechanism and provided a novel, effective approach for age-authentication of Baijiu and other liquors.
Aptamer-based rolling circle amplification (aptamer-RCA) was developed as a novel versatile electrochemical platform for ultrasensitive detection of protein. This method utilized antibodies ...immobilized on the electrode surface to capture the protein target, and the surface-captured protein was then sandwiched by an aptamer−primer complex. The aptamer−primer sequence mediated an in situ RCA reaction that generated hundreds of copies of a circular DNA template. Detection of the amplified copies via enzymatic silver deposition then allowed enormous sensitivity enhancement in the assay of target protein. This novel aptamer−primer design circumvented time-consuming preparation of the antibody−DNA conjugate for the common immuno-RCA assay. Moreover, the detection strategy based on enzymatic silver deposition enabled a highly efficient readout of the RCA product as compared to a redox-labeled probe based procedure that might exhibit low detection efficiency due to RCA product distance from the electrode. With the platelet-derived growth factor B-chain (PDGF-BB) as a model target, it was demonstrated that the presented method was highly sensitive and specific with a wide detection range of 4 orders of magnitude and a detection limit as low as 10 fM. Because of the wide availability of aptamers for numerous proteins, this platform holds great promise in ultrasensitive immunoassay.
Several studies have examined the functions of nucleic acids in small extracellular vesicles (sEVs). However, much less is known about the protein cargos of sEVs and their functions in recipient ...cells. This study demonstrates the presence of lysine‐specific demethylase 1 (LSD1), which is the first identified histone demethylase, in the culture medium of gastric cancer cells. We show that sEVs derived from gastric cancer cells and the plasma of patients with gastric cancer harbor LSD1. The shuttling of LSD1‐containing sEVs from donor cells to recipient gastric cancer cells promotes cancer cell stemness by positively regulating the expression of Nanog, OCT4, SOX2, and CD44. Additionally, sEV‐delivered LSD1 suppresses oxaliplatin response of recipient cells in vitro and in vivo, whereas LSD1‐depleted sEVs do not. Taken together, we demonstrate that LSD1‐loaded sEVs can promote stemness and chemoresistance to oxaliplatin. These findings suggest that the LSD1 content of sEV could serve as a biomarker to predict oxaliplatin response in gastric cancer patients.
Synopsis
Lysine specific demethylase 1 is not only a nuclear protein but is also secreted. Gastric cancer cells release sEVs that contain LSD1, thereby promoting cancer cell stemness and oxaliplatin resistance.
LSD1 is a component of small extracellular vesicles (sEVs) from gastric cancer cells and gastric cancer patient plasma.
LSD1‐containing sEVs increase the expression of Nanog, OCT4, SOX2 and CD44, and promote oxaliplatin resistance.
sEVs‐delivered LSD1 may serve as a potential biomarker to predict oxaliplatin response in the clinic.
Lysine specific demethylase 1 is not only a nuclear protein but is also secreted. Gastric cancer cells release sEVs that contain LSD1, thereby promoting cancer cell stemness and oxaliplatin resistance.
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