SIRT1 (Sir2) is an NAD
-dependent deacetylase that plays critical roles in a broad range of biological events, including metabolism, the immune response and ageing
. Although there is strong interest ...in stimulating SIRT1 catalytic activity, the homeostasis of SIRT1 at the protein level is poorly understood. Here we report that macroautophagy (hereafter referred to as autophagy), a catabolic membrane trafficking pathway that degrades cellular components through autophagosomes and lysosomes, mediates the downregulation of mammalian SIRT1 protein during senescence and in vivo ageing. In senescence, nuclear SIRT1 is recognized as an autophagy substrate and is subjected to cytoplasmic autophagosome-lysosome degradation, via the autophagy protein LC3. Importantly, the autophagy-lysosome pathway contributes to the loss of SIRT1 during ageing of several tissues related to the immune and haematopoietic system in mice, including the spleen, thymus, and haematopoietic stem and progenitor cells, as well as in CD8
CD28
T cells from aged human donors. Our study reveals a mechanism in the regulation of the protein homeostasis of SIRT1 and suggests a potential strategy to stabilize SIRT1 to promote productive ageing.
Soft scales (Hemiptera: Coccidae), including important agricultural and forestry pests, are difficult to identify directly by morphological characters. Mitochondrial genomes (mitogenomes) have been ...widely used in species identification and phylogenetic research. However, only three complete mitogenomes, and very few mitochondrial genes of scale insects (Hemiptera: Coccoidea) can be searched in GenBank. Mitogenome comparisons between scale insects or between scale insects and other hemipteran species have not yet been reported.
In this study, detailed annotation of three new mitogenomes and comparative analysis of scale insects were completed, as well as comparative analysis of the gene composition, gene arrangement, codon usage and evolutionary forces between scale insects and 488 other hemipteran species for the first time. We found that high A + T content, gene rearrangement and truncated tRNAs are common phenomena in soft scales. The average A + T content and codon usage bias of scale insects are higher and stronger than those of other hemipteran insects, respectively. The atp8 gene of Hemiptera and nine other protein-coding genes of scale insects are under positive selection with higher evolutionary rates.
The study revealed the particularity of the scale insect mitogenomes, which will provide a good reference for future research on insect phylogenetic relationships, insect pest control, biogeography and identification.
Transition metal nitrides (TMN) have recently grabbed immensely appealing as ideal active materials in energy storage and catalysis fields on account of their remarkable electrical conductivity, ...excellent chemical stability, wide band gap and tunable morphology. Both pure TMN and TMN-based materials have been extensively studied concerned with their preparation approaches, nanostructures, and favored performance in various applications. However, the processes towards synthesis of TMN are numerous and complex. Choosing appropriate method to obtain target TMN with desired structure is crucial, which further affects its practical application performance. Herein, this review offers a timely and comprehensive summary of the synthetic ways to TMN and their application in energy related domains. The synthesis section is categorized into in-situ and ex-situ based on where the N element in TMN origins from. Then, overviews on the energy related applications including energy storage, electrocatalysis and photocatalysis are discussed. In the end, the problems to be solved and the development trend of the synthesis and application of transition metal nitrides are prospected.
This review summarized the synthetic approaches toward metal nitride nanostructures by categorizing these methods into in-situ and ex-situ ones and presented their energy-related applications including energy storage, electrocatalysis and photocatalysis. Display omitted
•We innovatory categorized the synthesized methods into in-situ and ex-situ ones, which are discussed in the paper.•The energy-related applications of metal nitride nanostructures, including energy storage, electrocatalysis, and photocatalysis were summarized systematically.•Some challenges and prospects of this topic were outlined.
► The most nitrite accumulation occurred with glucose through denitrification. ► Higher COD/NO3-N ratios resulted in greater accumulation of nitrite. ► Competition for electrons between nitrite and ...nitrate reductase led to different reduction rates. ► pH and ORP validly regulate addition of carbon source without nitrite accumulation.
Effects of external carbon sources and COD/NO3-N on nitrite accumulation through denitrification were studied at a temperature of 28±2.0°C using mixed activated sludge. Nitrite accumulation was observed for each type of carbon source studied. Glucose resulted in the greatest nitrite accumulation and production rate, which were 14.51±2.41mg/L and 0.121±0.013gN/(gVSSd), respectively. Moreover, a higher COD/NO3-N ratio ranging from 1.0 to 15.0 increased accumulation to the maximum value of 0.34±0.03gN/(gVSSd). It was assumed that the competition for electrons between nitrite reductase and nitrate reductase led to different reduction rates and finally caused the accumulation. In addition, it was reasonable to use the pH and ORP as proxies for monitoring the real endpoint of the denitrification process with the addition of carbon sources.
•Wood pulping hydrolysate (WPH) was used for butanol production by C. beijerinckii.•Resin adsorption was effective to remove inhibitors in the hydrolysate.•Batch fermentation with gas stripping for ...butanol separation alleviated butanol toxicity.•ABE production reached 17.7g/L, the highest ever achieved in fermentation with WPH.•This process can be used to produce butanol from the abundant wood pulping waste.
Wood pulping hydrolysate (WPH) containing mainly xylose and glucose as a potential substrate for acetone–butanol–ethanol (ABE) fermentation was studied. Due to the inhibitors present in the hydrolysate, several dilution levels and detoxification treatments, including overliming, activated charcoal adsorption, and resin adsorption, were evaluated for their effectiveness in relieving the inhibition on fermentation. Detoxification using resin and evaporation was found to be the most effective method in reducing the toxicity of WPH. ABE production in batch fermentation by Clostridium beijerinckii increased 68%, from 6.73g/L in the non-treated and non-diluted WPH to 11.35g/L in the resin treated WPH. With gas stripping for in situ product removal, ABE production from WPH increased to 17.73g/L, demonstrating that gas stripping was effective in alleviating butanol toxicity by selectively separating butanol from the fermentation broth, which greatly improved solvents production and sugar conversion in the fermentation.
An Aquila optimizer-back propagation (AO-BP) neural network was used to establish an approximate model of the relationship between the design variables and the optimization objective to improve ...elevator block brake capabilities and achieve a lightweight brake design. Subsequently, the constraint conditions and objective functions were determined. Moreover, the multi-objective genetic algorithm optimized the structural block brake design. Finally, the effectiveness of the optimization results was verified using simulation experiments. The results demonstrate that the maximum temperature of the optimized brake wheel during emergency braking was 222.09°C, which is 36.71°C lower than that of 258.8°C before optimization, with a change rate of 14.2%. The maximum equivalent stress after optimization was 246.89 MPa, 28.87 MPa lower than that of 275.66 MPa before optimization, with a change rate of 10.5%. In addition, the brake wheel mass was reduced from 58.85 kg to 52.40 kg, and the thermal fatigue life at the maximum equivalent stress increased from 64 times before optimization to 94 times after optimization.
In order to protect the articles in buildings from ultraviolet radiation and save air-conditioning energy, polyvinyl butyral laminated glass are employed and produced in large quantities. Several ...inorganic particles with blocking effect have been doped into PVB, such as TiO
2
, ZnO, and ATO. T-ZnOw is a widely used functional structural material with excellent absorption properties. Herein, T-ZnOw was lipophilic modified with silane coupling agent KH-570, and T-ZnOw/PVB composite films were prepared via subsequent solution blending. As per the FTIR spectrum, a characteristic peak of Si–O–Zn at 1165 cm
−1
was observed, indicating that T-ZnOw was successfully modified by KH-570. T-ZnOw before and after modification was separately mixed with the St/H
2
O mixed solution. The modified T-ZnOw could be dispersed in styrene instead of water, displaying a certain lipophilicity. On the other hand, from a microscopic perspective, the SEM images suggest that filling the filler in the form of a suspension can disperse the modified T-ZnOw in PVB in an independent four-needle form, which contributes toward improvement of the agglomeration of T-ZnOw in the PVB matrix. The UV–Vis–NIR spectrum shows that the addition of T-ZnOw reduced the UV transmittance of T-ZnOw/PVB composite films from 50.84 to 25.77%, resulting in a decrease in near-infrared transmittance from 82.14 to 43.22%. The ultraviolet and near-infrared light barrier properties of composite films were more than twice that of the ordinary PVB films. Moreover, the modified T-ZnOw endowed composite films with stronger ultraviolet light and near-infrared light-blocking properties, or better visible light transmittance. And the falling ball impact test proved that there was no clear relationship between the thickness of the film and the adhesion. This work proposes a new solution and preparation method for the production of energy-saving glass. Therefore, it is expected that using composite films instead of traditional PVB films to make laminated glass can greatly contribute toward energy conservation and environmental protection.
Lysine lactylation (Kla) has recently been reported to participate in regulating transcription in human cells. However, the characterization, regulatory mechanism and functional consequence of Kla in ...prokaryotes remain unclear. Here, we report that YiaC functions as a lysine lactylase and that CobB serves as a lysine delactylase in the regulation of metabolism. We demonstrate that YiaC catalyzes the addition of Kla, while CobB erases this PTM both in vitro and intracellularly. Moreover, we show that YdiF can catalyze the formation of a lactyl-coenzyme A, which donates lactyl group for Kla. Quantitative proteomic analysis further reveals 446 endogenous Kla sites targeted by CobB and 79 candidates targeted by YiaC in Escherichia coli (E. coli). Furthermore, we present that Kla can influence the functions of metabolic enzymes. Interestingly, we demonstrate that CobB can specifically modulate the activity of PykF by regulating K382la, promoting glycolysis and bacterial growth. Our study identifies the regulatory enzymes and functional network of Kla and reveals a Kla-mediated molecular mechanism catalyzed by CobB for glycolysis regulation in E. coli.
To realize sustainable development, more and more countries forwarded carbon neutrality goal. Accordingly, improving the utilization efficiency of traditional fossil fuel is an effective strategy for ...this great goal. Keeping this in mind, developing thermoelectric devices to recover waste heat energy resulted in the consumption process of fuel is demonstrated to be promising. High performance thermoelectric devices require advanced materials. MXenes are a kind of 2D materials with a layered structure, which demonstrate excellent thermoelectric performance owing to their unique physical, mechanical, and chemical properties. Also, substantial achievement has been gained during the past few years in synthesizing MXene based materials for thermoelectric devices. In this review, the mainstream synthetic routes of MXene from etching MAX were summarized. Significantly, the current state and challenges of research on improving the performance of MXene based thermoelectrics are explored, including pristine MXene and MXene based composites.
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Materials chemistry; Materials application; Applied sciences
Abstract Most phloem-feeding insects face nutritional deficiency and rely on their intracellular symbionts to provide nutrients, and most of endosymbiont genomes have undergone reduction. However, ...the study of genome reduction processes of endosymbionts has been constrained by the limited availability of genome data from different insect lineages. The obligate relationship between aphids and Buchnera aphidicola (hereafter Buchnera ) makes them a classic model for studying insect-endosymbiont interaction. Here, we report 29 newly sequenced Buchnera genomes from 11 aphid subfamilies, and a comprehensive dataset based on 90 Buchnera genomes from 14 aphid subfamilies. The dataset shows a significant genomic difference of Buchnera among different aphid lineages. The dataset exhibits a more balanced distribution of Buchnera (from 14 aphid subfamilies) genome sizes, ranging from 400 kb to 600 kb, which can illustrate the genome reduction process of Buchnera . The new genome data provide valuable insights into the microevolutionary processes leading to genomic reduction of insect endosymbionts.
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