Aims
The objective of this study was to evaluate the potential of hexanoic acid (Hex) as a silage additive.
Methods and Results
The effect of Hex, Lactobacillus plantarum (Lp) and their combination ...(Hex + Lp) on the aerobic stability of napier grass silage was investigated. Napier grass was ensiled without additives (C) or with Lp, Hex or Hex + Lp for 60 days followed by 7 days of aerobic exposure. After 60 days of ensiling, the Lp silage had the lowest pH and the highest lactic acid (LA) concentration among all silage, whereas the highest water‐soluble carbohydrates (WSC) content was observed in Hex + Lp silage, followed by Hex silage. After 60 days of ensiling, the population of yeasts in C and Lp silages was > 3·0 log10 CFU per g FW, while that of Hex and Hex + Lp was <2·0 log10 CFU per g FW. During aerobic exposure, the pH in the Lp and C silages increased (P < 0·05) above 7·0 on day 5. The pH of Hex silage was the lowest among all silages on day 3 and 5, followed by a significant (P < 0·05) increase until 7 days of aerobic exposure. There were no significant changes in pH and AA of Hex + Lp silage over the duration of aerobic exposure. The concentrations of LA in C, Lp and Hex silages decreased while that of Hex + Lp silage remained stable after 3 days of aerobic exposure. The Hex delayed the decline of WSC contents and the increase in yeasts over the aerobic exposure period.
Conclusion
Addition of Hex (97 h) and Hex + Lp (>168 h) improved aerobic stability (P < 0·05) as compared to the control (83 h).
Significance and Impact of the Study
Hex or in combination with L. plantarum inhibited the proliferation of yeasts during aerobic exposure of napier grass. Thus, Hex is an alternative antifungal additive to improve aerobic stability.
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•The structures of microbial communities and DOM change in different redox zones.•Aerobic bacteria limit the reduction of Fe and As via depletion of O2 and NO3−.•SRB/FeRB promote ...reduction of As, Fe and SO42− by using protein-like DOM.•As-Fe-humic DOM complexation enhance the mobility of As and Fe in groundwater.•Microbial adaptative mechanisms on As stress are characterized by PLFAs.
The phospholipid fatty acids (PLFA) and dissolved organic matter (DOM) 3D fluorescent signatures were appointed to elaborate arsenic (As) mobilization mechanism in groundwater from the Datong Basin. Groundwater samples were collected along the groundwater flow path from recharge zones to discharge zones according to redox sensitive parameters. Variations of Eh, NO3− and SO42− manifested the redox condition shifted from a weakly oxidative environment to highly reductive environment. In recharge zones, some aerobic bacteria may serve as the dominant species, such as Thiothrix (S-oxidizing bacteria: SOB), Gallionella (Fe-oxidizing bacteria: FeOB) and Fluviicola, characterized by 16:1ω7, 16:0 and 18:1ω7 PLFAs. The biogeochemical processes were mainly governed by aerobic bacteria exploiting protein-like DOM as electron donors to maintain metabolism together with depleting of O2 and NO3− (electron acceptors), which restricted the reduction of As. While in discharge zones, the anaerobic microbes played a predominant role, such as Desulfosporosinus (Sulfate reducing bacteria: SRB) and Clostridia (Fe reducing bacteria: FeRB), indicated by cy17:0, cy19:0 and 18:1ω9 PLFAs. SRB and FeRB mainly utilized protein-like DOM as energy sources for respiratory action. Simultaneously, biogenic reductive dissolution of Fe(III) (hydr)oxides and reduction of As(V), SO42− resulted in geogenic immobilized As reductive desorption into aquifers. The positive linear correlations between humic substances and Fe, As suggested that As-Fe-DOM complexation can enhance the transport of As and Fe in aqueous environments. The negative relationships between SRB/FeRB and As/Fe concentrations demonstrated that the HS− could react with Fe(II) and As(III) to form secondary Fe(II) sulfides or As-bearing sulfides, which subsequently sequestered As from groundwater via sorption or coprecipitation. In conclusion, the utilization of biodegradable protein-like DOM by SRB/FeRB being associated with reductive dissolution of As-bearing Fe (hydr)oxides minerals and As-Fe-DOM complexation promoted As mobility in groundwater aquifers.
In this article, a deep learning model of precise electromagnetic (EM) response prediction for frequency selective surface (FSS) is proposed, incorporating both a new regularized learning strategy ...and a concatenated model structure. The preliminary prediction network (PPN) employs nine fully connected hidden layers and the elastic weight consolidation (EWC) regularization strategy is introduced during the training process. In the EWC regularization strategy, the new and old tasks are defined, effectively addressing the overfitting problem, thus improving the overall accuracy of EM response prediction. The residual compensation network (RCN) comprises three layers of fully connected networks, which are concatenated with the pre-trained PPN. The RCN can effectively compensate for the initial prediction errors of FSS, further improving the EM response prediction accuracy. Compared to artificial neural networks, deep neural networks, and convolutional neural networks, the proposed model demonstrates the lowest mean square errors in predicting the EM response of a typical single-band bandstop FSS and a dual-band bandpass FSS, with values of 2.96 and 4.39, respectively. Then, a dual-band bandpass FSS prototype is fabricated and measured. The measured results further validate the effectiveness of the concatenated structure with the EWC regularization strategy for predicting the EM response of FSS.
Duchenne muscular dystrophy (DMD) is a devastating disorder caused by loss of functional dystrophin protein, resulting in muscle wasting. Enhancing muscle growth by inhibiting myostatin, a growth ...factor negatively regulating skeletal muscle mass, is a promising approach to slow disease progression. Direct administration of myostatin propeptide, a natural inhibitor of mature myostatin, has shown limited efficacy probably due to low serum stability. Here, we demonstrate that serum stability, delivery efficiency and efficacy of propeptide can be significantly enhanced by anchoring propeptide to the surface of exosomes by fusing the inhibitory domain of myostatin propeptide into the second extracellular loop of CD63 (EXOpro). Repeated administrations of EXOpro accelerated muscle regeneration and growth, resulting in significantly increased muscle mass and functional rescue without any detectable toxicity in mdx mice. Importantly, EXOpro partially rehabilitated bone structure and promoted bone regeneration in mdx mice. Our findings demonstrate that anchoring to exosomes increased delivery and serum stability of propeptide and augmented the inhibitory efficacy of myostatin propeptide and thus provide a delivery platform for propeptide-based intervention in DMD.
Developing a low-cost and eco-friendly alternative to cement is of great significance for reducing CO2 emissions. Mine tailings (MTs) rich in Si and Al can be served as a promising precursor for ...geompolymer preparation only when the severe defect in the low reactivity is overcame. Alkali-hydrothermal activation technology was used to enhance the reactivity of MTs, and then activated tailings (ATs) and slag served as the precursors for the one-part geopolymer (OPG) preparation. Activation mechanism of MTs, workability, compressive strength, and hydration reactions of OPG samples were studied. The crystalline mineral phases in the MTs reacted with NaOH to form the amorphous sodium aluminosilicate, thus increasing the amorphization degree. High NaOH content favored the MTs activation, and the ATs with high NaOH content tended to create a higher initial pH and release more active species (Si and Al) for the slag hydration. The increase of NaOH content shortened the setting time, decreased the fluidity, and increased the strength of OPG samples. This was because the duration of the induction period was shortened and the hydration rate in the acceleration period of OPG samples was improved with increasing NaOH content, which generated large amounts of calcium–sodium aluminosilicate hydrate (C(N)-A-S-H) gel and yield the compact microstructure. However, excessive NaOH content resulted in a poor microstructure, and it is likely responsible for the reduction in strength.
•TP80-90 had higher concentration of anthocyanin and antioxidant activity than HHP.•HHP was better in maintaining the puree color than high temperature treatments.•PSC was correlated with total ...anthocyanin content.•TP80 - CAA was highest for blueberry puree.•Proper HHP treatment can activate PPO and β - glucosidase activity.
Thermal processing (TP) and high hydrostatic pressure (HHP) are two important puree processing methods. In this study, the polyphenol oxidase (PPO) and β-glucosidase activities, chromatic values, peroxide radical scavenging capacities (PSCs), cellular antioxidant activities (CAAs), and anthocyanin profiles were evaluated in blueberry puree following TP and HHP treatments. Nine anthocyanins were identified and cyanidin glycosides were the most abundant compounds in the blueberry puree sample. Petunidin-3-O-arabinoside, malvidin-3-O-galactoside, and malvidin-3-O-glucoside concentrations increased at temperatures of 70–90 °C (TP) and a pressure of 300 MPa (HHP). The highest total anthocyanin concentration (503.5 μg/mL) and PSC (13.45 µg VCE/mL) were observed following the TP (90 °C) treatment. Furthermore, a positive correlation was observed between the anthocyanin content and PSC (R2 = 0.655, P < 0.05). Finally, HHP treatment resulted in better puree color retention than TP treatment. The results of this study could provide valuable information for optimizing the processing methods for anthocyanin-rich products.
Blueberry (Vaccinium, family Ericaceae) is well known for its strong antioxidant properties and abundant active ingredients including anthocyanins, flavonols, and proanthocyanidins. In this study, ...variations in anthocyanin and phenolic compounds content in Bluecrop and Northblue blueberry cultivar fruits were studied, and comparative transcriptome analysis was performed to analyze differences in the molecular mechanisms of anthocyanin biosynthesis. A total of 13 799 unique genes were identified by differential expression analysis, and further subjected to GO classification and pathway enrichment. Nine differentially expressed genes (DEGs), including CHI, DFR, F3′H, FLS, CHS, OMT, UGT, ANS and F3H, were selected to validate the differential expression data using quantitative real-time PCR. The obtained qRT-PCR expression results were consistent with the RNA-Seq results. The expression levels of 9 candidate genes involved in flavonoid biosynthesis and metabolism were concurrent with the anthocyanin content. The developmental stage appeared to affect the expression of genes related to flavonoid biosynthesis to a greater extent than the tissue or cultivar type. This study provides an abundant data resource that will further our understanding of the molecular mechanisms of anthocyanin biosynthesis in blueberries.
•TPC and TAC in different tissues and fruit development stages of two blueberry cultivars were examined.•The biosynthetic pathway and metabolism of flavonoids was further characterized.•Several candidate genes associated with flavonoid biosynthesis were identified.•Comparative transcriptome analysis provided genetic evidence on the differences between the different blueberry cultivars.
High As groundwater has been reported in aquifers comprising Late Pleistocene and Holocene sediments worldwide, and could be due to the depositional environment and sedimentological processes. To ...investigate the paleoenvironment and chemical weathering as mechanisms controlling the fate of As, this study characterized the elemental, clay mineral, and Li isotopic compositions of sediments of an As-contaminated aquifer in the Datong Basin, China. Indices for reconstructing chemical weathering conditions, for example, the Chemical Index of Alternation (CIA), indicate overall incipient to intermediate chemical weathering conditions in the Datong Basin during the Late Pleistocene to Holocene. The higher CIA values at depths of ∼20–∼85 m indicate stronger chemical weathering and a shift in climatic regime towards warm and humid conditions in Stage 2 compared to Stage 1 and Stage 3. Under such climatic conditions, intense chemical weathering favors the leaching of silicate-bound Fe and thus the production of various secondary Fe-oxide minerals. Besides, the positive relationship between CIA values and easily reducible Fe oxides further shows the enrichment of more weakly crystalline Fe-oxides during the depositional condition; this finding is also supported by the results of chemical extractions performed on the sediments. Moreover, the good correlations between total organic carbon (TOC) and both Fe/Na and As concentrations suggest the enrichment of As and OM along with Fe enrichment during chemical weathering; this is attributed to the adsorption or co-precipitation of As and OM on Fe minerals. Under warm and humid conditions, intense chemical weathering released a large amount of Fe minerals; As was also released due to stronger weathering of the terrestrial bedrock and sequestered by Fe oxides and organic matter, thus forming complexes involving As, Fe, and OM. FTIR and chemical extraction results confirm the formation of As–Fe-OM complexes during the geological history contributes to As enrichment and accumulation in the late Pleistocene sediments. These findings provide new insights into the interaction between the paleoenvironment and the accumulation of ferric oxides/hydroxides and OM, which serve as controlling mechanisms with respect to As enrichment in Late Pleistocene to Holocene sediments, and thus shed light on the sedimentogenesis of high As aquifers.
•Paleoenvironment controls on As accumulation in sediments was discussed.•Warm and humid conditions governed the accumulation of Fe oxides and organic matter co-burial.•Formation of As–Fe-OM complexes is the mechanism of As enrichment in aquifer sediments.
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•The N, O coordination number on ORR and OER catalytic activity is explored by DFT.•RhN3O1-1 and IrN3O1-1 have the excellent ORR catalytic activity.•Mulliken charge analysis can ...effectively reveal the origin of the activity.
The reaction rate of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is an important factor restricting its application. In this work, we have systematic explorated of N, O coordination number on the catalytic performance for ORR and OER. Firstly, a variety of stability analysis methods show that most of the catalysts have excellent stability. Secondly, a series of excellent bifunctional catalysts are screened by volcanic maps, ORR overpotential (ηORR), OER overpotential (ηOER), and bifunctional index (BI), such as, RhN3O1-1 (ηORR = 0.28 V, ηOER = 0.34 V, BI = 0.62 V) and CoN3O1-1 (ηORR = 0.33 V, ηOER = 0.37 V, BI = 0.70 V). In particular, RhN3O1-1 has the smallest BI value, indicating that it has the best bifunctional catalytic activity. This study offers insights into how the coordination environment affects the activity of OER/ORR.
Background Unruptured intracerebral aneurysm wall enhancement (AWE) on vessel wall magnetic resonance imaging scans may be a promising predictor for rupture-prone intracerebral aneurysms. However, ...the pathophysiology of AWE remains unclear. To this end, the association between AWE and histopathological changes was assessed in this study. Methods and Results A total of 35 patients with 41 unruptured intracerebral aneurysms who underwent surgical clipping were prospectively enrolled. A total of 27 aneurysms were available for histological evaluation. The macroscopic and microscopic features of unruptured intracerebral aneurysms with and without enhancement were assessed. The microscopic features studied included inflammatory cell invasion and vasa vasorum, which were assessed using immunohistochemical staining with CD68, CD3, CD20, and myeloperoxidase for the former and CD34 for the latter. A total of 21 (51.2%) aneurysms showed AWE (partial AWE, n=7; circumferential AWE, n=14). Atherosclerotic and translucent aneurysms were identified in 17 and 14 aneurysms, respectively. Aneurysm size, irregularity, and atherosclerotic and translucent aneurysms were associated with AWE on univariate analysis (
<0.05). Multivariate logistic regression analysis showed that atherosclerosis was the only factor significantly and independently associated with AWE (
=0.027). Histological assessment revealed that inflammatory cell infiltration, intraluminal thrombus, and vasa vasorum were significantly associated with AWE (
<0.05). Conclusions Though AWE on vessel wall magnetic resonance imaging scans may be associated with the presence of atherosclerotic lesions in unruptured intracerebral aneurysms, inflammatory cell infiltration within atherosclerosis, intraluminal thrombus, and vasa vasorum may be the main pathological features associated with AWE. However, the underlying pathological mechanism for AWE still needs to be further studied.
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