Temperature is a key factor that contributes to microbially induced calcium carbonate precipitation. At low temperatures, low enzyme activity results in a lack of calcium precipitation. In this ...study,
Sporosarcina pasteurii
and
Bacillus megaterium
were compared. Firstly, the optical density curves and enzyme activity curves of both bacteria were obtained during 48-h culture. Then, optical density, enzyme activity, and productive rates for calcium carbonate were measured to analyze the influence of temperature. Finally, the effect of urea concentration on carbonate precipitation was studied by changing the urea concentration that was added during inoculation. The obtained results showed that at high temperature, the growth rate of
B. megaterium
was close to that of
S. pasteurii
, while the opposite result was found at low temperature. The urease activities of
B. megaterium
were similar at different temperature conditions. At high temperature,
B. megaterium
showed lower enzyme activity, while at low temperature, it surpassed that of
S. pasteurii
. The same results were found for enzyme activity and for the precipitation rates of calcium carbonate. The addition of urea to the medium increased precipitation rates, and higher urea concentrations increased the obtained precipitation rates. With 20 g/L urea, the precipitation rate of
B. megaterium
at 15 °C matched that without urea addition at 30 °C. Therefore, adding urea to the medium at the time of inoculation can effectively overcome the low calcium precipitation at low temperature and enable subsequent low-temperature engineering applications.
Mobile colistin resistance (mcr) genes represent an emerging challenge. Here we describe a novel mcr gene, mcr-10, on an IncFIA plasmid of an Enterobacter roggenkampii clinical strain. mcr-10 has the ...highest nucleotide identity (79.69%) with mcr-9 and encodes MCR-10 with 82.93% amino acids identical to MCR-9. mcr-10 confers 4-fold increase in colistin MIC (from 1 to 4 mg/L) when cloned into a colistin-susceptible E. roggenkampii strain. By screening GenBank, mcr-10 was found in various Enterobacteriaceae species of countries in four continents, suggesting that this gene has widely spread. MCR-10 shows 79.04% to 83.67% amino acid identity and highly conserved predicted protein structures with chromosomally encoded MCR-like phosphoethanolamine transferases (designated MCR-B here) of various Buttiauxella species. MCR-10, MCR-9 and MCR-B proteins may, therefore, originate from a common ancestor. mcr-10 was adjacent to a site-specific recombinase-encoding gene and was bracketed by IS903 and may be mobilized by site-specific recombination or composite transposon. Our results indicate that mcr-10 is a novel plasmid-borne colistin resistance gene and warrants immediate monitoring and further studies.
•The pair of SF-FO parameters were optimized for SEBM processing of SS316L alloy•SEBM-built SS316L samples exhibit longitudinal microstructural heterogeneity•SEBM-built SS316L samples have higher ...strength and higher ductility along the build direction•σ phase precipitation along grain boundaries reduces the strength of SEBM-built SS316L samples
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This work presents an experimental study of process optimization of the pair of critical parameters (speed function (SF) and focus offset (FO)) for stainless steel 316L (SS316L) parts additively manufactured by selective electron beam melting (SEBM). Here, there are two sets of optimized SF-FO parameters that could build SS316L parts with high relative densities (>99%) and well-melted top build surfaces. Tensile test results show that most of the SEBM-built SS316L samples exhibit higher tensile strengths than the conventional cast and wrought counterparts, whereas their ductility is lower. In addition, strong anisotropic tensile properties are observed for the SEBM-built SS316L samples, e.g. they generally have better tensile properties when loaded parallel to the build direction as compared to the horizontal direction. However, a large number of σ phase was found to precipitate at grain boundaries in the SS316L samples fabricated under lower SF and larger FO with a higher build temperature, which evidently deteriorates their tensile properties particularly for the horizontal direction. It is suggested that SEBM process parameters for SS316L must be optimized to avoid σ phase precipitation at elevated temperatures apart from a well-melted top build surface and a high relative density.
More voices are calling for a quicker transition towards clean energy. The exploration and exploitation of clean energy such as wind energy and solar energy are effective means to optimise energy ...structure and improve energy efficiency. To provide in-depth understanding of clean energy transition, this paper utilises a combination of multiple bibliometric mapping techniques, including HistCite, CiteSpace and R Bibliometrix, to conduct a systematic review on 2,191 clean energy related articles obtained from Web of Science (WoS). We identify five current main research streams in the clean energy field, including Energy Transition, Clean Energy and Carbon Emission Policy, Impact of Oil Price on Alternative Energy Stocks, Clean Energy and Economics, and Venture Capital Investments in Clean Energy. Clearly, the effectiveness of policy-driven and market-driven energy transition is an important ongoing debate. Emerging research topics are also discussed and classified into six areas: Clean Energy Conversion Technology and Biomass Energy Utilisation, Optimisation of Energy Generation Technology, Policy-Making in Clean Energy Transition, Impact of Clean Energy Use and Economic Development on Carbon Emissions, Household Use of Clean Energy, and Clean Energy Stock Markets. Accordingly, more and more research attention has been paid to how to improve energy efficiency through advanced clean energy technology, and how to make targeted policies for clean energy transition and energy market development. This article moves beyond the traditional literature review methods and delineates a systematic research agenda for clean energy research, providing research directions for achieving low-carbon development through the clean energy transition.
Light is a major environmental cue affecting various physiological and metabolic processes in plants. Although plant photoreceptors are well characterized, the mechanisms by which light regulates ...downstream responses are less clear. In Arabidopsis thaliana, the accumulation of photoprotective anthocyanin pigments is light dependent, and the R2R3 MYB transcription factor MYB75/PAP1 regulates anthocyanin accumulation. Here, we report that MYB75 interacts with and is phosphorylated by MAP KINASE4 (MPK4). Their interaction is dependent on MPK4 kinase activity and is required for full function of MYB75. MPK4 can be activated in response to light and is involved in the light-induced accumulation of anthocyanins. We show that MPK4 phosphorylation of MYB75 increases its stability and is essential for light-induced anthocyanin accumulation. Our findings reveal an important role for a MAPK pathway in light signal transduction.
Objective:
Epithelial-mesenchymal transition (EMT) is a tightly regulated and dynamic process occurring in both embryonic development and tumor progression. Our study aimed to comprehensively explore ...the molecular subtypes, immune landscape, and prognostic signature based on EMT-related genes in low-grade gliomas (LGG) in order to facilitate treatment decision-making and drug discovery.
Methods:
We curated EMT-related genes and performed molecular subtyping with consensus clustering algorithm to determine EMT expression patterns in LGG. The infiltration level of diverse immune cell subsets was evaluated by implementing the single-sample gene set enrichment analysis (ssGSEA) and ESTIMATE algorithms. The distinctions in clinical characteristics, mutation landscape, and immune tumor microenvironment (TME) among the subtypes were subjected to further investigation. Gene Set Variation Analysis (GSVA) was performed to explore the biological pathways that were involved in subtypes. The chemo drug sensitivity and immunotherapy of subtypes were estimated through GDSC database and NTP algorithm. To detect EMT subtype-related prognostic gene modules, the analysis of weighted gene co-expression network (WGCNA) was performed. The LASSO algorithm was utilized to construct a prognostic risk model, and its efficacy was verified through an independent CGGA dataset. Finally, the expression of the hub genes from the prognostic model was evaluated through the single-cell dataset and
in-vitro
experiment.
Results:
The TCGA-LGG dataset revealed the creation of two molecular subtypes that presented different prognoses, clinical implications, TME, mutation landscapes, chemotherapy, and immunotherapy. A three-gene signature (SLC39A1, CTSA and CLIC1) based on EMT expression pattern were established through WGCNA analysis. Low-risk patients showed a positive outlook, increased immune cell presence, and higher expression of immune checkpoint proteins. In addition, several promising drugs, including birinapant, fluvastatin, clofarabine, dasatinib, tanespimycin, TAK−733, GDC−0152, AZD8330, trametinib and ingenol-mebutate had great potential to the treatment of high risk patients. Finally, CTSA and CLIC1 were highly expressed in monocyte cell through single-cell RNA sequencing analysis.
Conclusion:
Our research revealed non-negligible role of EMT in the TME diversity and complexity of LGG. A prognostic signature may contribute to the personalized treatment and prognostic determination.
Electrochromic materials have great application in soft displays and devices, but the application of ideal electrochromic textiles still faces challenges owing to the inconvenience of a continuous ...power supply. Here, electrochromic color-memory microcapsules (ECM-Ms-red, -yellow, and -blue) with a low drive voltage (2.0 V), coloration efficiency (921.6 cm2 C–1), a practical response rate (34.4 s–1), multistage response discoloration, and good color-memory performance (>72 h) and reversibility (≥1000 cycles) are developed. The color-memory performance is controlled by the energy difference of oxidation–reduction reactions. A multicolor and multistage response electrochromic color-memory wearable smart textile and flexible display are developed that are convenient and energy-efficient for application. The design philosophy of color-memory based on controllable energy difference of reactions has great potential application in sensors and smart textiles.
Raspberry ketone is an important ingredient in the flavor and fragrance industries. Due to its low content in fruits and vegetables, the production of natural raspberry ketone using heterologous ...synthesis in microbial strains is recently attracting increased attention. In this work, a heterologous pathway to produce raspberry ketone from
p
-coumaric acid, including 4-coumarate: CoA ligase (4CL), benzalacetone synthase (BAS), and raspberry ketone/zingerone synthase (RZS1) from plants, was successfully assembled in
Escherichia coli
. When the RZS1 gene was introduced into
E. coli
and co-expressed with two other genes, the intermediate 4-hydroxybenzylidene acetone in the pathway was almost completely transformed into a raspberry ketone. Substituting TB medium for M9 medium increased raspberry ketone titers by 3–4 times. Furthermore, the heterologous pathway was partitioned into two modules; module one produced
p
-coumaroyl-CoA from
p
-coumaric acid by 4CL, and module two produced raspberry ketone from coumaroyl-CoA by the action of BAS and RZS1. Optimizing the balanced expression of the two modules, it was shown that moderate expression of module one and high expression of module two was the best combination to enhance raspberry ketone production. The engineered strain CZ-8 reached 90.97 mg/l of raspberry ketone, which was 12 times higher than previously reported. In addition, the preferred approach of the heterologous pathway was related to the heterologous genes from different sources; for example, 4CL from
Arabidopsis thaliana
seemed to be more suitable for raspberry ketone production than that from
Petroselinum crispum
. This work paves an alternative way for future economic production of natural raspberry ketone.
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► RGO–ZrO(OH)2 was prepared by hydro-thermal co-precipitation method. ► RGO–ZrO(OH)2 had high adsorption capacity for both As(III) and As(V). ► RGO–ZrO(OH)2 showed high adsorption ...capacity in wide pH range. ► RGO–ZrO(OH)2 exhibited good anti-interference ability to co-existing anions. ► Adsorption equilibrium of As(III, V) on RGO–ZrO(OH)2 was obtained within 15min.
Hydrated zirconium oxide (ZrO(OH)2) nanoparticles were modified with graphite oxide (GO) (denoted herein as GO–ZrO(OH)2) by hydro-thermal co-precipitation reaction, and were used for the simultaneous removal of As(III) and As(V) from drinking water. The GO–ZrO(OH)2 nanocomposites were characterized using Fourier transformer infrared spectroscopy, X-ray diffraction analysis, high resolution transmission electron microscopy, Zeta-potential, and specific surface area analysis. The size of ZrO(OH)2 particles in GO–ZrO(OH)2 is below 5nm, and the specific surface area of GO–ZrO(OH)2 is about 4 times that of ZrO(OH)2 nanoparticles. The GO–ZrO(OH)2 nanocomposites showed high adsorption capacity in a wide pH range, and the monolayer adsorption amounts calculated based on the Langmuir adsorption model were 95.15 and 84.89mg/g for As(III) and As(V), respectively, which are 3.54 and 4.64 times that of ZrO(OH)2 nanoparticles. The high adsorption capacity is attributed to good dispersion of ZrO(OH)2 nanoparticles in the GO substrate. The GO–ZrO(OH)2 nanocomposites can simultaneously remove As(III) and As(V) in water. Moreover, GO–ZrO(OH)2 showed good anti-interference ability to co-existing anions, and exhibited excellent recyclability. The experimental results suggest that GO–ZrO(OH)2 is a promising adsorbent for the removal of arsenic from drinking water.
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