718 research outputs found

    Proteiniphilum and Methanothrix harundinacea became dominant acetate utilizers in a methanogenic reactor operated under strong ammonia stress

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    Microorganisms in anaerobic digestion (AD) are easily affected by ammonia, especially acetoclastic methanogens. Thus, in ammonia-suppressed AD systems, acetate degradation is reported to be carried out mainly by the cooperation of syntrophic acetate oxidizers and hydrogenotrophic methanogens. Previous studies have revealed ammonia inhibition on microbial flora by AD performance, but the effect mechanism of ammonia on microbial metabolism remains poorly understood. In this study, we constructed a mesophilic chemostat fed with acetate as the sole carbon source, gradually increased the total ammonia nitrogen (TAN) concentration from 1 g L−1 to 6 g L−1, and employed the 16S rRNA gene, metagenomics, and metatranscriptomics analysis to characterize the microbial community structure and metabolic behavior. The results showed that even at the TAN of 6 g L−1 (pH 7.5), the methanogenesis kept normal, the biogas production was approximately 92% of that at TAN of 1 g L−1 and the acetate degradation ratio reached 99%, suggesting the strong TAN tolerance of the microbial community enriched. 16S rRNA gene analysis suggested that the microbial community structure changed along with the TAN concentration. Methanothrix predominated in methanogens all the time, in which the dominant species was gradually replaced from M. soehngenii to M. harundinacea with the increased TAN. Dominant bacterial species also changed and Proteiniphilum showed a significant positive correlation with increased TAN. Meta-omics analysis showed that the absolute dominant microorganisms at TAN of 6 g L−1 were M. harundinacea and Proteiniphilum, both of which highly expressed genes for anti-oxidative stress. M. harundinacea and the second dominant methanogen Methanosarcina highly expressed both acetate cleavage and CO2 reduction pathways, suggesting the possibility that these two pathways contributed to methanogenesis together. Proteiniphilum and some other species in Firmicutes and Synergistetes were likely acetate oxidizers in the community as they highly expressed genes for syntrophic acetate oxidization, H2 generation, and electron transfer. These results suggested that Proteiniphilum as well as M. harundinacea have strong ammonia tolerance and played critical roles in acetate degradation under ammonia-suppressed conditions. The achievements of the study would contribute to the regulation and management of the AD process

    Optical coherence tomography angiography for macular microvessels in ischemic branch retinal vein occlusion treated with conbercept: predictive factors for the prognosis

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    AIM: To evaluate the predicative factors of visual prognosis using optical coherence tomography angiography (OCTA) in ischemic branch retinal vein occlusion (BRVO) patients with macular edema (ME) after anti-vascular endothelial growth factor (VEGF) treatment. METHODS: In this retrospective analysis, data from 60 patients (60 eyes) with a definite diagnosis of ischemic BRVO with ME by fundus fluorescein angiography (FFA) were studied. The eyes with ME according to spectral domain optical coherence tomography (SD-OCT) underwent intravitreal conbercept (IVC) and 3+pro re nata (PRN) regimen. The injection times were recorded. Two weeks after injection, fundus laser photocoagulation was performed in the non-perfusion area of the retina. The patients were followed up once a month for 6mo. The best-corrected visual acuity (BCVA), foveal avascular zone (FAZ), and A-circularity index (AI), at 6mo and the baseline were compared. RESULTS: All patients showed significant improvement in BCVA from 0.82±0.32 to 0.39±0.11 logMAR (P<0.001). The mean central macular thickness (CMT) significantly decreased from 476.22±163.54 to 298.66±109.23 μm. Both the FAZ area and AI at 6mo were significantly higher than those at the baseline: the FAZ area increased (0.38±0.02 vs 0.39±0.02 mm², P<0.05); the AI increased (1.27±0.02 vs 1.31±0.01, P=0.000). The baseline BCVA showed a significantly positive correlation with the baseline FAZ area, FAZ perimeter (PERIM) and AI, final visual gain (FVG) and injection times, respectively (P<0.001). FVG showed a significantly negative correlation with the FAZ area, PERIM, AI and injection times, but a significantly positive correlation with vessel densities (VDs) 300 µm area around FAZ (FD-300; P<0.001). Injection times was positively correlated with the baseline FAZ area, and AI, but inversely correlated with the baseline FD-300 (P<0.001). However macular ischemia was noted in 5 cases during follow-up. CONCLUSION: Using OCTA to observe macular ischemia and quantify parameters can better predict the final visual prognosis of patients before treatment. The changes in FAZ parameters may influence the visual prognosis and injection times

    Seismic Risk Assessment and Rehabilitation Method of Existing RCC Structures Using Micro Concrete

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    Aging reinforced concrete (RC) building structures typically experience more severe damage and are prone to collapse during earthquakes, constituting a primary factor in casualties and direct economic losses. To enhance the seismic performance of these old structures, this paper proposes a seismic risk assessment and a micro-concrete restoration method. It applies the process to an existing three-story reinforced concrete structure. A practical framework for mitigating structural vulnerabilities in seismic-prone regions was proposed. Then an as-built survey was conducted to create as-built architectural and structural drawings. Concrete core tests, ferroscans, and rebar tests were also performed. Based on field surveys and test data, nonlinear static and dynamic analyses have been used to evaluate structural safety. Concrete column jacketing was used to strengthen weak existing columns with micro-concrete. In assessing the structural response of retrofitted buildings, a comparison was made to their initial state. The comparison shows that applying concrete column jacketing with micro concrete can reduce other structural elements' demand capacity ratio (DCR), minimize maximum displacements, and enhance overall stiffness. The results indicate that the proposed method effectively evaluates the seismic risk of aging structures and enhances seismic resilience in existing buildings. Moreover, the application to the actual structure demonstrates that micro-concrete is highly durable and compatible with parent-concrete. Doi: 10.28991/CEJ-2023-09-12-04 Full Text: PD

    An Approach of One-vs-Rest Filter Bank Common Spatial Pattern and Spiking Neural Networks for Multiple Motor Imagery Decoding

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    Motor imagery (MI) is a typical BCI paradigm and has been widely applied into many aspects (e.g. brain-driven wheelchair and motor function rehabilitation training). Although significant achievements have been achieved, multiple motor imagery decoding is still unsatisfactory. To deal with this challenging issue, firstly, a segment of electroencephalogram was extracted and preprocessed. Secondly, we applied a filter bank common spatial pattern (FBCSP) with one-vs-rest (OVR) strategy to extract the spatio-temporal-frequency features of multiple MI. Thirdly, the F-score was employed to optimise and select these features. Finally, the optimized features were fed to the spiking neural networks (SNN) for classification. Evaluation was conducted on two public multiple MI datasets (Dataset IIIa of the BCI competition III and Dataset IIa of the BCI competition IV). Experimental results showed that the average accuracy of the proposed framework reached up to 90.09% (kappa: 0.868) and 81.33% (kappa: 0.751) on the two public datasets, respectively. The achieved performance (accuracy and kappa) was comparable to the best one of the compared methods. This study demonstrated that the proposed method can be used as an alternative approach for multiple MI decoding and it provided a potential solution for online multiple MI detection

    ESC-Derived Basal Forebrain Cholinergic Neurons Ameliorate the Cognitive Symptoms Associated with Alzheimer’s Disease in Mouse Models

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    SummaryDegeneration of basal forebrain cholinergic neurons (BFCNs) is associated with cognitive impairments of Alzheimer’s disease (AD), implying that BFCNs hold potentials in exploring stem cell-based replacement therapy for AD. However, studies on derivation of BFCNs from embryonic stem cells (ESCs) are limited, and the application of ESC-derived BFCNs remains to be determined. Here, we report on differentiation approaches for directing both mouse and human ESCs into mature BFCNs. These ESC-derived BFCNs exhibit features similar to those of their in vivo counterparts and acquire appropriate functional properties. After transplantation into the basal forebrain of AD model mice, ESC-derived BFCN progenitors predominantly differentiate into mature cholinergic neurons that functionally integrate into the endogenous basal forebrain cholinergic projection system. The AD mice grafted with mouse or human BFCNs exhibit improvements in learning and memory performances. Our findings suggest a promising perspective of ESC-derived BFCNs in the development of stem cell-based therapies for treatment of AD

    Number of parous events affects the association between physical exercise and glycemic control among women with gestational diabetes mellitus:A prospective cohort study

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    BACKGROUND: Multiparous women are at a higher risk of gestational diabetes mellitus (GDM) than primiparas. Physical activity during pregnancy has been shown to be beneficial for GDM, but there is little evidence on the association between physical activity and glycemic control among women with GDM, whether primiparas or multiparas. Thus, the objective of the present study was to examine the association between physical activity and glycemic control in women with GDM and to determine what, if any, effects result from number of parous events. METHODS: A prospective cohort of 1162 women with GDM was recruited, with 604 multiparas (51.98%). The general linear model was used to calculate the risk difference and its 95% confidence interval (95%CI) to quantify the impact of parous events on glycemic control in pregnancy as well as the association between physical activity time and glycemic control. RESULTS: Among 1162 women with GDM, the median daily activity time was 65 min (interquartile range (IQR): 45–90 min), and the abnormal plasma glucose (PG) percentage, calculated as number of abnormal PG tests divided by the total number of PG tests, was 40.00% (IQR: 22.22%–66.67%). The percentage of abnormal PG was stabilized and statistically lower with daily physical activity time exceeding 60 min among primiparas (IQR: 30.89%–44.43%) and exceeding 90 min among multiparas (ranged from 27.76% to 38.82%). After adjusting for potential confounders, primiparas tended to have a lower percentage of abnormal PG than do multiparas (rate difference = –0.39, 95%CI: –3.61 to 2.84). The same amount of physical activity time was significantly less effective for multiparas than for primiparas (trend p-value < 0.01). CONCLUSION: In women with GDM, being multiparous is associated with less effective glycemic control through physical activity, such that multiparas need more physical activity to achieve glycemic control at a similar level to primiparas

    ITO-Free Semitransparent Organic Solar Cells Based on Silver Thin Film Electrodes

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    ITO-free semitransparent organic solar cells (OSCs) based on MoO3/Ag anodes with poly(3-hexylthiophene) and [6,6]-phenyl-C61-butyric acid methyl ester films as the active layer are investigated in this work. To obtain the optimal transparent (MoO3)/Ag anode, ITO-free reference OSCs are firstly fabricated. The power conversion efficiency (PCE) of 2.71% is obtained for OSCs based on the optimal MoO3 (2 nm)/Ag (9 nm) anode, comparable to that of ITO-based reference OSCs (PCE of 2.85%). Then based on MoO3 (2 nm)/Ag (9 nm) anode, ITO-free semitransparent OSCs with different thickness combination of Ca and Ag as the cathodes are investigated. It is observed from our results that OSCs with Ca (15 nm)/Ag (15 nm) cathode have the optimal transparency. Meanwhile, the PCE of 1.79% and 0.67% is obtained for illumination from the anode and cathode side, respectively, comparable to that of similar ITO-based semitransparent OSCs (PCE of 1.59% and 0.75% for illumination from the anode and cathode side, resp.) (Sol. Energy Mater. Sol. Cells, 95, pp. 877–880, 2011). The transparency and PCE of ITO-free semitransparent OSCs can be further improved by introducing a light couple layer. The developed method is compatible with various substrates, which is instructive for further research of ITO-free semitransparent OSCs
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