Biochar applied to soil can reduce nitrous oxide (N
2
O) emissions produced by freeze–thaw processes. Nonetheless, how biochar modification affects N
2
O emissions during freeze–thaw cycles is not ...completely clear. In our research, during freeze–thaw cycles, microcosm experiments were conducted to investigate the effects of maize straw biochar (MB) or rice straw biochar (RB) addition on soil N
2
O emissions under different water conditions. The N
2
O emissions peaked at the initial stage of thawing in all the soils, and the total N
2
O emissions were considerably greater in the flooded soils than in the nonflooded soils. Compared with the soils without biochar addition, RB and MB amendments inhibited N
2
O emissions by 69 and 67%, respectively. Moreover, after biochar addition, the abundance of AOB
amoA
genes decreased by 9–13%. Biochar addition significantly decreased the content of microbial biomass nitrogen (MBN) in flooded soil during thawing, which was significantly correlated with N
2
O emissions and nitrification and denitrification communities. The PLS-PM further revealed that biochar can inhibit the production and emission of soil N
2
O by reducing soil MBN during soil thawing. In addition, soil moisture directly significantly affects N
2
O emissions and indirectly affects N
2
O emissions through its influence on soil physicochemical properties. Our results revealed the important function of biochar in decreasing the emission of N
2
O in flooded soil during freeze–thaw cycles.
Direct electric curing (EC) is a new green curing method for cement-based materials that improves the early mechanical properties via the uniform high temperature produced by Joule heating. To ...understand the effects of EC and steam curing (SC) on the mechanical properties and microstructure of cement-based materials, the mortar was cured at different temperature-controlled curing regimes (40 °C, 60 °C, and 80 °C). Meanwhile, the mechanical properties, hydrates and pore structures of the specimens were investigated. The energy consumption of the curing methods was compared. The results showed that the EC specimens had higher and more stable growth of mechanical strength. The hydration degree and products of EC samples were similar to that of SC samples. However, the pore structure of EC specimens was finer than that of SC specimens at different curing ages. Moreover, the energy consumption of EC was much lower than that of SC. This study provides an important technical support for the EC in the production of energy-saving and high early-strength concrete precast components.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The emergence of coronavirus disease 2019 (COVID-19) posed a major challenge to healthcare systems worldwide, especially as mutations in the culprit Severe Acute Respiratory Syndrome Coronavirus 2 ...(SARS-CoV-2) complicated the development of vaccines and antiviral drugs. Therefore, the search for natural products with broad anti-SARS-CoV-2 capabilities is an important option for the prevention and treatment of similar infectious diseases. Lectins, which are widely recognized as antiviral agents, could contribute to the development of anti-SARS-CoV-2 drugs. This study evaluated the binding affinity of six lectins (including the cyanobacterial lectin from Microcystis viridis NIES-102 (MVL), and Jacalin, a lectin from the breadfruit, Artocarpus altilis) to the receptor binding domain (RBD) of the spike protein on the original (wild) SARS-CoV-2 and three of its mutants: Alpha, Delta, and Omicron. MVL and Jacalin showed distinct binding affinity to the RBDs of the four SARS-CoV-2 strains. The remaining four lectins (DB1, ConA, PHA-M and CSL3) showed no such binding affinity. Although the glycan specificities of MVL and Jacalin were different, they showed the same affinity for the spike protein RBDs of the four SARS-CoV-2 strains, in the order of effectiveness Alpha > Delta > original > Omicron. The verification of glycan-specific inhibition revealed that both lectins bind to RBDs by glycan-specific recognition, but, in addition, MVL binds to RBDs through protein–protein interactions.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Amino acid transporters are promising targets for engineering acid‐tolerant strains of Lactococcus lactis. However, the simple overexpression of transporters alone is insufficient to achieve a highly ...acid‐resistant phenotype. This study investigated the effects of amino acid transporters on the acid‐stress tolerance of L. lactis. Here, we first verified the contribution of amino acid transporters to acid tolerance by overexpressing the ctrA, glnP, and glnQ genes in L. lactis. Transcriptome analysis revealed that most genes associated with specific amino acid transport, pyrimidine metabolism, and functional proteins, were upregulated in the overexpression strains. Among them, arginine biosynthesis (argG and argH), amino acid transport (yjeM and azlC), and pyrimidine metabolism were considered to be the most important regulatory mechanisms. Importantly, metabolite profiling revealed that the overexpression strains had higher intracellular levels of amino acids, particularly aspartate, glutamate, and arginine at low pH, as well as higher intracellular ATP levels, which was consistent with the corresponding gene‐expression levels. Finally, the simultaneous overexpression of glnP and glnQ led to a further improvement of acid tolerance in L. lactis. This study reveals the regulatory mechanisms of amino acid transporters, and provides a novel strategy for achieving higher acid tolerance via positive tandem expression approaches.
This study reveals a putative regulatory mechanism of amino acid transporters, and provides a novel strategy for achieving higher acid tolerance via positive tandem expression approaches.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Probiotics contribute a lot to human health and the occurrence of diseases. Correspondingly, probiotics’ safety evaluation and probiotic properties have received increasing attention in the food ...industry and disease treatment.
Clostridium tyrobutyricum
L319 is a short-chain fatty acid (SCFA)-producing strain isolated from Grana Padano cheese with a blowing defect. Our previous study has shown its safety at the genomic level. This study focused more on the safety evaluation and probiotic properties
in vitro
. According to the results, this strain has no potential virulence factors or the possibility of antibiotic resistance genes propagation. It also fulfilled several criteria to be used as a probiotic, including significant hydrophobicity under an acidic condition (pH 5.0) and resistance to simulate gastric juice and intestinal juice. Additionally, this strain was found to be tolerant to the harsh conditions of the external environment, including resistance to low (20°C) and high (50°C) temperatures, high salts (3% NaCl), and low pH (pH 5.0). Finally, we found that this strain could ferment prebiotics, such as chito-oligosaccharides, to produce SCFAs. It exhibited excellent growth performance whether using chito-oligosaccharide as a sole carbon source or combining glucose as the mixed carbon source. Furthermore, chito-oligosaccharide and glucose (1:1) mixed carbon sources were the optimal strategy for the production of SCFAs. Our findings demonstrated that this strain might be considered a promising candidate for future use as a probiotic to promote health benefits.
Deinococcus wulumuqiensis R12, which was isolated from arid irradiated soil in Xinjiang province of China, belongs to a genus that is well-known for its extreme resistance to ionizing radiation and ...oxidative stress. The DNA-binding protein Dps has been studied for its great contribution to oxidative resistance. To explore the role of Dps in D. wulumuqiensis R12, the Dps sequence and homology-modeled structure were analyzed. In addition, the dps gene was knocked out and proteomics was used to verify the functions of Dps in D. wulumuqiensis R12. Docking data and DNA binding experiments in vitro showed that the R12 Dps protein has a better DNA binding ability than the Dps1 protein from D. radiodurans R1. When the dps gene was deleted in D. wulumuqiensis R12, its resistance to H.sub.2O.sub.2 and UV rays was greatly reduced, and the cell envelope was destroyed by H.sub.2O.sub.2 treatment. Additionally, the qRT-PCR and proteomics data suggested that when the dps gene was deleted, the catalase gene was significantly down-regulated. The proteomics data indicated that the metabolism, transport and oxidation-reduction processes of D. wulumuqiensis R12 were down-regulated after the deletion of the dps gene. Overall, the data conformed that Dps protein plays an important role in D. wulumuqiensis R12.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
China’s large-scale construction has led to massive energy consumption and carbon emissions. The embodied carbon emissions (ECs) of China’s building sector play a key role in realizing national ...emission reduction targets. Currently, the understanding of the status quo of ECs is vague and inconsistent, and the existing accounting models still have several limitations. Therefore, this study develops two improved models (i.e., the process-based and the input-output-based life cycle assessment models) and dynamic accounting datasets to reveal historical trends and emission characteristics of ECs from 2005 to 2020. The results show that the total ECs in 2020 were as high as 2.28 billion tCO2, accounting for 25.2% of China’s total energy-related carbon emissions. The indirect ECs are the largest contributor, representing 95.9% of the total building ECs. The ECs increased quickly at first and entered a plateau, stable at about 2.2 billion tCO2 after 2015. From 2005 to 2020, the total building ECs contributed 38.7% to the national carbon emission growth, while the intensity of ECs showed a downward trend, indicating that the increase in China’s building ECs is scale-driven. This study provides sound methodological, and data support for emission tracing and the low-carbon development of China’s building sector.
Human somatic cells can be reprogrammed to pluripotent stem cells by small molecules through an intermediate stage with a regeneration signature, but how this regeneration state is induced remains ...largely unknown. Here, through integrated single-cell analysis of transcriptome, we demonstrate that the pathway of human chemical reprogramming with regeneration state is distinct from that of transcription-factor-mediated reprogramming. Time-course construction of chromatin landscapes unveils hierarchical histone modification remodeling underlying the regeneration program, which involved sequential enhancer recommissioning and mirrored the reversal process of regeneration potential lost in organisms as they mature. In addition, LEF1 is identified as a key upstream regulator for regeneration gene program activation. Furthermore, we reveal that regeneration program activation requires sequential enhancer silencing of somatic and proinflammatory programs. Altogether, chemical reprogramming resets the epigenome through reversal of the loss of natural regeneration, representing a distinct concept for cellular reprogramming and advancing the development of regenerative therapeutic strategies.
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•Human chemical reprogramming activates regeneration gene program•Epigenome remodeling of regeneration gene program with enhancer recommissioning•Chemically resetting epigenome through reversal of the loss of natural regeneration•Regeneration program activation requires silencing somatic and inflammatory programs
By performing single-cell transcriptomic and histone modification profiling of the chemical reprogramming process, Wang et al. unveil the epigenome remodeling underlying activation of the regeneration program. They discover that sequential enhancer recommissioning and promoter activation mirrors a reversed pathway of regeneration loss in organism maturation and demonstrate the intrinsic barriers to this process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Along with the construction industrialization degree, precast concrete is being utilized more and more frequently in construction to speed up the process and guarantee the quality of structural ...concrete. In order to make the precast concrete reach the required strength quickly and speed up the turnover of formwork, various rapid concrete curing methods emerged. Currently steam curing, direct electric curing, and microwave curing are the widely studied rapid curing methods. Rapid curing methods could promote early strength growth by changing the internal and external temperature and humidity of concrete, but may lead to late strength shrinkage, increased internal micro-cracks, coarsening of pore structure and other problems. Based on the comprehensive analysis of the curing principles of the three rapid curing methods, this paper reviews the effects of the three rapid curing methods on the hydration process, properties, and microscopic pore structure of concrete. The shortcomings of different rapid curing methods, and the topics of future researchs are also included.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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