SIRT6 mediated histone H3K9ac deacetylation involves myocardial remodelling through regulating myocardial energy metabolism in TAC mice.

Pathological myocardial remodelling is the initial factor of chronic heart failure (CHF) and is induced by multiple factors. We previously demonstrated that histone acetylation is involved in CHF in transverse aortic constriction (TAC) mice, a model for pressure overload-induced heart failure. In this study, we investigated whether the histone deacetylase Sirtuin 6 (SIRT6), which mediates deacetylation of histone 3 acetylated at lysine 9 (H3K9ac), is involved pathological myocardial remodelling by regulating myocardial energy metabolism and explored the underlying mechanisms. We generated a TAC mouse model by partial thoracic aortic banding. TAC mice were injected with the SIRT6 agonist MDL-800 at a dose of 65 mg/kg for 8 weeks. At 4, 8 and 12 weeks after TAC, the level of H3K9ac increased gradually, while the expression of SIRT6 and vascular endothelial growth factor A (VEGFA) decreased gradually. MDL-800 reversed the effects of SIRT6 on H3K9ac in TAC mice and promoted the expression of VEGFA in the hearts of TAC mice. MDL-800 also attenuated mitochondria damage and improved mitochondrial respiratory function through upregulating SIRT6 in the hearts of TAC mice. These results revealed a novel mechanism in which SIRT6-mediated H3K9ac level is involved pathological myocardial remodelling in TAC mice through regulating myocardial energy metabolism. These findings may assist in the development of novel methods for preventing and treating pathological myocardial remodelling.

Use of Dual-Task Timed-Up-and-Go Tests for Predicting Falls in Physically Active, Community-Dwelling Older Adults-A Prospective Study.

This prospective study aimed to determine which specific mobility tests were the most accurate for predicting falls in physically active older adults living in the community. Seventy-nine physically active older adults who met the American College of Sports Medicine physical activity guidelines volunteered. Participants were assessed and followed up for 12 months. Mobility assessments included the 30-s sit-to-stand test, five times sit-to-stand test, single-task timed-up-and-go test (TUG), motor dual-task TUG (Mot-TUG), and cognitive dual-task TUG (Cog-TUG). Mot-TUG and Cog-TUG performances were moderately correlated with number of falls (r = .359, p < .01 and r = .372, p < .01, respectively). When Mot-TUG, Cog-TUG, or Age were included as fall predictors, discrimination scores represented by the area under the receiver operating characteristic curve (AUC) were AUC (Mot-TUG) = 0.843 (p < .01), AUC (Cog-TUG) = 0.856 (p < .01), and AUC (Age) = 0.734 (p < .05). The cutoff point for Cog-TUG was 10.98 s, with test sensitivity of 1.00 and specificity of 0.66. Fall predictors for different populations may be based on different test methods. Here, the dual-task TUG test more accurately predicted falls in older adults who met American College of Sports Medicine's physical activity guidelines.

Rolling circle amplification promoted magneto-controlled photoelectrochemical biosensor for organophosphorus pesticides based on dissolution of core-shell MnO2 nanoflower@CdS mediated by butyrylcholinesterase.

A photoelectrochemical (PEC) aptasensing platform is devised for sensitive detection of an organophosphorus pesticide based on dissolution of core-shell MnO2 nanoflower@CdS (MnO2 NF@CdS) by thiocholine (TCh). TCH is produced from the butyrylcholinesterase-acetylthiocholine system, accompanied by target-triggered rolling circle amplification (RCA). The core-shell MnO2 NF@CdS with excellent PEC performance was synthesized and employed as a photo-sensing platform. The target was detected on a functionalized magnetic probe with the corresponding aptamer. Upon malathion introduction, the aptamer was detached from the magnetic beads, while capture DNA (cDNA, with primer fragment) remained on the beads. The primer fragment in cDNA can trigger the RCA reaction to form a long single-stranded DNA (ssDNA). Furthermore, a large number of butyrylcholinesterase (BChE) were assembled on the long ssDNA strands through the hybridization with the S2-Au-BChE probe. Thereafter, TCh generated from hydrolysis of ATCh by BChE can reduce MnO2 NF (core) to Mn2+ and release the CdS nanoparticles (shell) from the platform electrode, significantly enhancing the PEC signal. Under optimal conditions, the proposed aptasensor exhibited high sensitivity for malathion with a low detection limit of 0.68 pg mL-1. Meanwhile, it also presents outstanding specificity, reproducibility, and stability. Importantly, the sensing platform provides a new concept for detection of pesticide. Graphical abstract Herein, this work devised a photoelectrochemical (PEC) aptasensing platform for sensitive detection of organophosphorus pesticide based on dissolution of core-shell MnO2 nanoflower@CdS (MnO2 NF@CdS) by the as-produced thiocholine (TCh) from the butyrylcholinesterase-acetylthiocholine system, accompanying with the target-triggered rolling circle amplification (RCA).

Interaction between in vivo bioluminescence and extracellular electron transfer in Shewanella woodyi via charge and discharge.

Extracellular electron transfer (EET) and bioluminescence are both important for microbial growth and metabolism, but the mechanism of interaction between EET and bioluminescence is poorly understood. Herein, we demonstrate an exclusively respiratory luminous bacterium, Shewanella woodyi, which possesses EET ability and electron communication at the interface of S. woodyi and solid substrates via charge and discharge methods. Using an electro-chemiluminescence apparatus, our results confirmed that the FMN/FMNH2 content and the redox status of cytochrome c conjointly regulated the bioluminescence intensity when the potential of an indium-tin oxide electrode was changed. More importantly, this work revealed that there is an interaction between the redox reaction of single cells and bioluminescence of group communication via the EET pathway.

A Novel Zero Velocity Interval Detection Algorithm for Self-Contained Pedestrian Navigation System with Inertial Sensors.

Zero velocity update (ZUPT) plays an important role in pedestrian navigation algorithms with the premise that the zero velocity interval (ZVI) should be detected accurately and effectively. A novel adaptive ZVI detection algorithm based on a smoothed pseudo Wigner-Ville distribution to remove multiple frequencies intelligently (SPWVD-RMFI) is proposed in this paper. The novel algorithm adopts the SPWVD-RMFI method to extract the pedestrian gait frequency and to calculate the optimal ZVI detection threshold in real time by establishing the function relationships between the thresholds and the gait frequency; then, the adaptive adjustment of thresholds with gait frequency is realized and improves the ZVI detection precision. To put it into practice, a ZVI detection experiment is carried out; the result shows that compared with the traditional fixed threshold ZVI detection method, the adaptive ZVI detection algorithm can effectively reduce the false and missed detection rate of ZVI; this indicates that the novel algorithm has high detection precision and good robustness. Furthermore, pedestrian trajectory positioning experiments at different walking speeds are carried out to evaluate the influence of the novel algorithm on positioning precision. The results show that the ZVI detected by the adaptive ZVI detection algorithm for pedestrian trajectory calculation can achieve better performance.

Azithromycin attenuates wheezing after pulmonary inflammation through inhibiting histone H3K27me3 hypermethylation mediated by EZH2.

BACKGROUND: Histone methylation modification plays an irreplaceable role in the wheezing diseases. The aim of this study was to explore whether azithromycin (AZM) attenuates post-inflammatory wheezing through inhibiting hypermethylation of histone H3K27me3 mediated by EZH2. RESULTS: A randomized controlled trial was conducted on 227 children who underwent fiber-optic bronchoscopy, and bronchoalveolar lavage fluid (BALF) was collected for analyses. The expressions of IL-6, IL-2, NF-κB P65, EZH2 and H3K27me3 in the BALF of wheezing cases were significantly increased when compared with levels in non-wheezing cases (P < 0.05), while IL-10 was decreased (P < 0.05). AZM attenuated the overexpression of NF-κB P65, EZH2 and H3K27me3 in wheezing cases (P < 0.05) and shortened the time of wheezing in wheezing cases (P < 0.05). An in vitro model of inflammation was established using rat alveolar macrophages induced by lipopolysaccharide (LPS). AZM, SN50 (a NK-κB inhibitor) and GSK126 (an EZH2 inhibitor) attenuated the overexpression of EZH2, NF-κB P65 and H3K27me3 induced by LPS in rat alveolar macrophages (P < 0.05). AZM, SN50 and GSK126 normalized the decreased expression of IL-10 induced by LPS in the same samples (P < 0.05). Co-immunoprecipitation results showed that H3K27me3 interacted with EZH2 and NF-κB P65, and immunofluorescence data showed that AZM and SN50 inhibited LPS-induced NF-κB P65 nuclear translocation in rat alveolar macrophages. CONCLUSION: Histone H3K27me3 hypermethylation mediated by EZH2 may be involved in wheezing after pulmonary inflammation. AZM attenuated wheezing after pulmonary inflammation by inhibiting NF-κB P65-related hypermethylation of H3K27me3 mediated by EZH2.

Lumichrome from the photolytic riboflavin acts as an electron shuttle in microbial photoelectrochemical systems.

Riboflavin has been proposed to serve as an electron shuttle in photoelectrochemical systems. However, riboflavin was also observed for abiotic photolysis under illumination. Such conflicting reports raise the necessity for further investigation. In this study, riboflavin secreted by Rhodopseudomonas palustris was studied to clarify its stability and electron shuttle function under illumination. The data of high-performance liquid chromatography-mass spectrometry showed that the riboflavin was photolyzed to lumichrome in microbial photoelectrochemical systems. In addition, the anodic current increased by 75% after adding lumichrome compared with that of the control; it further demonstrated that lumichrome, not riboflavin, as an electron shuttle could facilitate microbial electron transfer. This study clarifies the mechanism of the interface process in microbial photoelectrochemical systems.

Efficient lead immobilization by bio-beads containing Pseudomonas rhodesiae and bone char.

Mineralization of lead ions (Pb2+) to pyromorphite using phosphorus-containing materials is an effective way to remediate lead (Pb) contamination. Bone char is rich in phosphorus, but its immobilization of Pb2+ is limited by poor phosphate release. To utilize the phosphorus in bone char and provide a suitable growth environment for phosphate-solubilizing bacteria, bone char and Pseudomonas rhodesiae HP-7 were encapsulated into bio-beads, and the immobilization performance and mechanism of Pb in solution and soil by bio-beads were investigated. The results showed that 137 mg/g of phosphorus was released from bone char in the presence of the HP-7 strain. Pb2+ removal efficiency reached 100 % with an initial Pb2+ concentration of 1 mM, bone char content of 6 g/L, and bio-bead dosage of 1 %. Most Pb2+ was immobilized on the surface of the bio-beads as Pb5(PO4)3Cl. The soil remediation experiments showed a 34 % reduction in the acid-soluble fraction of Pb. The bio-beads showed good stability in long-term (30 d) soil remediation. The present study shows that bone char can be turned into an efficient Pb immobilization material in the presence of phosphate-solubilizing bacteria. Thus, bio-beads are expected to be used in the remediation of Pb-contaminated environments.

Enhanced interfacial electron transfer between semiconductor and non-photosynthetic microorganism under visible light.

Under visible light, non-photosynthetic microorganism/semiconductor has recently shown promising applications in biofuel production, bioenergy generation and pollutant removal. However, the understanding of electron transfer mechanism at the biotic-abiotic interface is limited. Herein, mixed culture/carbon nitride and pure culture (Stenotrophomonas maltophilia HP14)/carbon nitride were constructed to reveal the energy conversion pathway under visible light. Enhanced electron transfer was observed on the biotic-abiotic interface. The photocurrent of non-photosynthetic S. maltophilia HP14/g-C3N4/ITO with riboflavin addition was 10.2-fold higher than that of g-C3N4/ITO control. As the electron donor, S. maltophilia HP14 transfer bio-electrons to self-secreted riboflavin and valence band of semiconductor. Riboflavin (RF) accept bio-electrons and photogenerated electrons to form 1,5-dihydroflavin (RFH2). While RFH2 is able to transfer electrons to the valence band of carbon nitride and transform into RF again. However, riboflavin is not stable under visible light irradiation, which may lead to a decreased photocurrent. This study demonstrated the role of redox active compounds at the microorganism/semiconductor interface and described a possibility for non-photosynthetic microorganisms to capture and utilize visible light.

Transforming cerussite to pyromorphite by immobilising Pb(II) using hydroxyapatite and Pseudomonas rhodesiae.

Lead (Pb) pollution has become one of the most serious environmental problems in recent decades. However, there are few remediation technologies for insoluble cerussite (PbCO3), which are common in the environment and have high bioavailability. In this study, the immobilisation of Pb(II) released from PbCO3 by Pseudomonas rhodesiae HP-7 isolated from Pb-contaminated soil was studied. The results showed that hydroxyapatite and PbCO3 were dissolved by the organic acids secreted by the HP-7 strain, and then the dissolved Pb2+ and H2PO4- reacted to form low bioavailable Pb5(PO4)3Cl precipitate. XRD and mass conservation calculations showed that 85.7% of PbCO3 was transformed to Pb5(PO4)3Cl when P:Pb was 9:5. Our research showed that the HP-7 strain and hydroxyapatite could reduce the bioavailability of Pb(II) in PbCO3, which could be used for the remediation of Pb-polluted environments.

Functional role of mixed-culture microbe in photocatalysis coupled with biodegradation: Total organic carbon removal of ciprofloxacin.

Ciprofloxacin is an extensively used fluoroquinolone antibiotic, which exists in aquatic environment, causing detrimental effects to the aquatic ecosystem and thus, indirectly to humans. Thus, an efficient and rapid removal method for ciprofloxacin is urgently needed. Intimately coupled photocatalysis and biodegradation has proven to be highly efficient, low-cost, and eco-friendly. In this study, cube polyurethane sponges modified with visible light-responsive g-C3N4 and mixed culture microbes were used to increase the ciprofloxacin removal efficiency. Subsequently, 94% of ciprofloxacin was removed by photocatalytic-biodegradation and 12 degradation products and possible degradation pathways were analyzed. Photocatalytic-biodegradation had a 1.57 times higher total organic carbon (TOC) removal rate than photocatalytic degradation. The microbial community structure after 72 h of photocatalytic biodegradation was examined. High microbial richness, evenness, and functional dominant species belong to Proteobacteria, which were closely associated with the utilization of antibiotics, may be majorly responsible for the highly efficient removal degradation process. Additionally, microbes retarded the interaction of photogenerated electrons and holes, which may contribute to the increasing mineralization. The findings demonstrated the potential ability of photocatalytic biodegradation in degrading bio-recalcitrant compounds and provide new insights into photocatalytic coupled with biodegradation for removal of ciprofloxacin.

Degradation of low-concentration perfluorooctanoic acid via a microbial-based synergistic method: assessment of the feasibility and functional microorganisms.

Perfluorooctanoic acid (PFOA) is persistent in the environment. The activities of microorganisms alone are insufficient for the decomposition of PFOA, but microorganisms can contribute positively to the degradation of PFOA in synergistic systems. Herein, a synergistic system combining photocatalytic decay with microbial degradation of the transformation products was applied to degrade 500.0 µg L-1 PFOA. The microorganisms increased the total removed percentage by 30.7% to a final percentage of 79.7 ± 9.4% in comparison with the photocatalytic method alone. Moreover, an additional 44.2% of removed total organic carbon and additional defluorination percentage of 24.5% were obtained after the synergistic tests. The 16S RNA sequencing analysis indicated that Stenotrophomonas, Bacillus, Pseudomonas, and Brevundimonas were highly enriched in the functional microbial community, which was simultaneously shaped by photocatalysis and substances. This study found it would be feasible to use a synergistic method containing photocatalysis and a microbial community for the degradation of low-concentrations of PFOA, and the results provided a reference to modified the removal efficiency of the synergistic system by looking insight into the relationship between the functional microbial community and PFOA.

Interspecific competition by non-exoelectrogenic Citrobacter freundii An1 boosts bioelectricity generation of exoelectrogenic Shewanella oneidensis MR-1.

The performance of bioelectrochemical systems (BESs) is significantly influenced by metabolic interactions within a particular microbial community. Although some studies show that interspecific metabolic cooperation benefits BESs performance, the effect of interspecific substrate competition on BESs performance has not yet been discussed. Herein, the impact of interspecific competition is investigated by monitoring the extracellular electron transfer of exoelectrogenic Shewanella oneidensis MR-1 and non-exoelectrogenic Citrobacter freundii An1 alone and simultaneously. The bacterial consortia generate the highest current of 38.4 µA cm-2, 6 times of that produced by the single strain S. oneidensis MR-1. Though S. oneidensis MR-1 loses out to C. freundii An1 in solution, the competition enhances the metabolic activity of S. oneidensis MR-1 on electrode, which facilitates the biofilm formation and therefore helps S. oneidensis MR-1 to gain an competitive advantage over C. freundii An1. Increased metabolic activity triggers more electrons generation and flavin secretion of S. oneidensis MR-1 which contributes to its excellent exoelectrogenic capacity. The proteomics analysis confirms that the expression of proteins related to lactate metabolism, biofilm formation, and outer membrane c-type cytochromes are significantly upregulated in S. oneidensis MR-1 from bacterial consortia.

Molecular Dynamics Simulation Study of a CO2-Switchable Surfactant.

We computed molecular properties of a long-tail amidine surfactant (N'-dodecyl-N,N-dimethylacetamidinium bicarbonate, DDAB) through quantum mechanics (QM) method. We then used molecular dynamics (MD) computations to obtain the properties of DDAB when displaced from the center to the boundary surface. The QM calculation results indicated that the mono-dentate type of bindings between polar head group and HCO-3 ion was more likely to be adopted. The MD results indicated that the HCO-3 ions could pass the energy barrier surrounding the head groups to form stable ion pairs. Meanwhile, the surfactant molecules aggregated very quickly, and absorbed in a direction pointed from the bulk center to the boundary. These results indicated that hydrophobic correlations of alkyl chains are the driving force for boundary adsorption of DDAB.

Antibiotic resistance genes are increased by combined exposure to sulfamethoxazole and naproxen but relieved by low-salinity.

Combined pollution of antibiotic and non-antibiotic pharmaceutical residues is ubiquitous in realistic polluted environments, which is regarded as a complicated emerging pollution. Herein, high-throughput sequencing and high-throughput quantitative PCR were applied to profile the overall changes in microbial communities and antibiotic resistance genes (ARGs) of biofilms in response to a combination of naproxen and sulfamethoxazole pollution. After continuous operation for 120 days, naproxen or/and sulfamethoxazole were efficiently removed, and the salinity of 1.00% enhanced the removal rate of sulfamethoxazole. The high-throughput sequencing revealed that Eubacterium spp. with abundances of over 40.00% dominated in all samples, and combined pollution of naproxen and sulfamethoxazole more readily promoted the occurrence of multidrug-resistant microbes, including Pseudomonas and Methylophilus. The high-throughput quantitative PCR results showed that the combined pollution of naproxen and sulfamethoxazole increased the total abundance of ARGs to approximately 9 copies per cell. In contrast, increasing the salinity to 1.00% greatly reduced the overall abundance of ARGs to below 2 copies per bacterial cell. Mantel test and Procrustes analysis indicated that microbiomes from different treatments had tight links to their respective antibiotic resistomes. Furthermore, network analysis revealed that multidrug-resistant microbes were potential hosts for greatly enriched numbers of ARGs in the combined treatment. As increased salinity eliminated those multidrug-resistant but salt-sensitive microbes, the abundance of ARGs was significantly decreased. These results showed the high probability of the transmission of ARGs in biofilms exposed to combined pollution of naproxen and sulfamethoxazole, which could be relieved by increased salinity.

Leaching of indium from end-of-life LCD panels via catalysis by synergistic microbial communities.

Currently, a large amount of discarded liquid crystal displays (LCDs) are being produced, and the improper treatment of discarded LCDs causes serious environmental pollution problems. Indium is the most valuable metal in LCDs and is present in such devices at a concentration of over 0.025%. In this study, the bioleaching of indium from end-of-life LCD panels was comprehensively investigated through three methods: S-mediated pathway, Fe-mediated pathway and Mixed pathway of S- and Fe-mediated, which yielded maximum bioleaching efficiencies of approximately 100%, 0% and 78%, respectively. Microbial community analysis showed that the dominant functional bacteria under the S-mediated pathway were Acidithiobacillus. The Acidithiobacillus genus catalysed the leaching of indium, which was mainly achieved by indirect bioleaching. In addition, the microorganisms can secrete enzymes and extracellular polymeric substances, which also contributed to the leaching of indium. Therefore, this work provides an economical and efficient biological method for future research and practical applications in indium recovery from solid waste.

Long-term operation of electroactive biofilms for enhanced ciprofloxacin removal capacity and anti-shock capabilities.

Few studies have focused on the feasibility of microbial fuel cells (MFCs) for removing quinolones antibiotics and their anti-shock capabilities. After 1.5 years of operation, the removal efficiency of 10 mg/L ciprofloxacin in MFCs increased to 99.00% in 88 h. These results are in accordance with the enhanced activity of biofilms and voltage output of MFCs. Additionally, the anti-shock capacities of the biofilms in MFCs were evaluated by treating ofloxacin and enrofloxacin and operating at different temperature and salinity. These MFCs can remove 87.31% and 40.81% of ofloxacin and enrofloxacin in 72 h, respectively. Even exposed to a low temperature of 10 °C or a salinity of 3%, the MFCs can achieve greater than 50% and nearly 80% of ciprofloxacin removal efficiency, respectively. The enrichment of Alcaligenes and Chryseobacterium contributed mostly to the removal of quinolones antibiotics. This study provides scientific evidences for treating wastewater containing quinolones antibiotics using MFCs.

Interactions between iron mineral-humic complexes and hexavalent chromium and the corresponding bio-effects.

The interfacial behaviors of chromium are fundamental for understanding the environmental effects of chromium in contaminated environments. However, complex surfaces can cause chromium to exhibit a variety of behaviors, especially when humic substances are considered. This work illustrated the role of humics (humic acid and fulvic acid) during the adsorption of Cr(VI) onto iron minerals (magnetite and hematite). The interfacial behaviors were investigated through their adsorption kinetics, adsorption isotherms, and thermodynamics. Then, the microbial diversity was monitored to reflect the bio-effects of Cr(VI) adsorbed onto four iron oxide-humic complexes. The differences in the adsorption capacities and mechanisms of Cr(VI) on the surfaces of the iron mineral-humic complexes were observed. Humics obviously decreased the adsorption capacities of Cr(VI) on the hematite complexes and relieved the decline in the microbial diversity; meanwhile, humics imposed relatively insignificant changes to the Cr(VI) adsorption capacity onto the magnetite complexes. Thus, the corresponding microbial diversity might be mainly affected by released micelles formed by Cr(VI) and humics. These results illustrate the complexities of the interfacial behaviors of Cr(VI) on the surfaces of iron mineral-humic complexes and broaden the current understanding of chromium migration and transportation.

One-pot synthesis of single-crystalline PtPb nanodendrites with enhanced activity for electrooxidation of formic acid.

Bimetallic PtPb nanodendrites with a single-crystalline structure were obtained by a facile one-pot strategy. The as-synthesized dendritic structure was well characterized and the growth mechanism was investigated. PtPb nanodendrites exhibited superior activity (5.1 times higher than commercial Pd black) and strong anti-poisoning ability for electrooxidation of formic acid.