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Odd chain fatty acids (OCFAs) are high-value-added compounds with great application in the field of food and medicine. As an oleaginous microorganism, Schizochytriumsp. has the potential to produce OCFAs efficiently. Propionyl-CoA is used as a precursor to synthesize OCFAs through the fatty acid synthetase (FAS) pathway, so its flow direction determines the yield of OCFAs. Here, different substrates were assessed to promote propionyl-CoA supply for OCFA accumulation. Moreover, the methylmalonyl-CoA mutase (MCM) was identified as the key gene responsible for propionyl-CoA consumption, which promotes the propionyl-CoA to enter into the tricarboxylic acid cycle rather than the FAS pathway. As one of the classic B12-dependent enzymes, the activity of MCM can be inhibited in the absence of B12. As expected, the OCFA accumulation was greatly increased. However, the removal of B12caused growth limitation. Furthermore, the MCM was knocked out to block the consumption of propionyl-CoA and to maintain cell growth; results showed that the engineered strain achieved the OCFAs titer of 2.82 g/L, which is 5.76-fold that of wild type. Last, a fed-batch co-feeding strategy was developed, resulting in the highest reported OCFAs titer of 6.82 g/L. This study provides guidance for the microbial production of OCFAs.

It is well known that polyunsaturated fatty acids (PUFAs) in Schizochytriumsp. are mainly synthesized via the polyketide synthase (PKS) pathway. However, the specific mechanism of PKS in fatty acid synthesis is still unclear. In this work, the functions of ORFA, ORFB, ORFC, and their individual functional domain genes on fatty acid synthesis were investigated through heterologous expression in Yarrowia lipolytica. The results showed that the expression of ORFA, ORFB, ORFC, and their individual functional domains all led to the increase of the very long-chain PUFA content (mainly eicosapentaenoic acid). Furthermore, the transcriptomic analysis showed that except for the 3-ketoacyl-ACP synthase (KS) domain of ORFB, the expression of an individual functional domain, including malonyl-CoA: ACP acyltransferase, 3-hydroxyacyl-ACP dehydratase (DH), 3-ketoacyl-ACP reductase, and KS domains of ORFA, acyltransferase domains of ORFB, and two DH domains of ORFC resulted in upregulation of the tricarboxylic acid cycle and pentose phosphate pathway, downregulation of the triacylglycerol biosynthesis, fatty acid synthesis pathway, and β-oxidation in Yarrowia lipolytica. These results provide a theoretical basis for revealing the function of PKS in fatty acid synthesis in Y. lipolyticaand elucidate the possible mechanism for PUFA biosynthesis.

Flavonoids, including dihydroflavonols and anthocyanins, are phenolic compounds with significant biological activity, playing a crucial role in the sensory characteristics and health benefits of wine. In this study, we selected the naringenin-producing strain HB52 （Saccharomyces cerevisiae） as the starting strain and introduced synthetic pathways for dihydroflavonols and anthocyanins, achieving de novo synthesis of various flavonoid compounds. To further optimize flavonoid production, we employed several strategies, including overexpressing 5-enolpyruvylshikimate 3-phosphate synthase to enhance metabolic flux, integrating NADPH regeneration genes, and using citric acid/isocitric acid transporter genes to increase the levels of cofactors. Additionally, organelle engineering was utilized to strengthen the β-oxidation pathway, thereby elevating the levels of precursors such as acetyl-coenzyme A (CoA) and malonyl-CoA. Engineered strains significantly improved their ability to synthesize various flavonoids directly from glucose. In the final engineered strains, the production levels of NAR, DHQ, and DHM in the dihydroflavonol-engineered strains reached 379.2 mg/L, 231.3 mg/L, and 284.8 mg/L, respectively. The anthocyanin-engineered strains achieved the highest yield of anthocyanin synthesized from glucose in S. cerevisiae, reaching 45.7 mg/L (33.4 mg/L for C3G and 12.3 mg/L for D3G). This study highlights the potential of metabolic and organelle engineering in S. cerevisiaeto increase flavonoid production, offering new prospects for enhancing sensory quality and health benefits in the wine industry.

Mississippi Valley-type (MVT) Pb-Zn deposits serve as the world’s major supply of Pb-Zn resources. However, the age constraint of MVT Pb-Zn deposits has long been a big challenge, due to the lack of minerals that are unequivocally related to ore deposition and that can be used for radioisotopic dating. Here we show sporopollens can provide useful chronological information on the Changdong MVT Pb-Zn deposit in the Simao basin, Sanjiang belt, West China. The Pb-Zn ores in the Changdong deposit are hosted by internal sediments in paleo-karst caves of meteoric origin. Sphalerite and galena occur as replacements of carbonate minerals and void infillings in the internal sediments. The relations suggest that the Pb-Zn mineralization occurred after the deposition of the internal sediments. A palynological assemblage mainly composed of angiosperm pollen dominated by Castanea, Quercus, and Caryaand fern spores dominated by Polypodiaceae, Pteris, and Athyriaceae was identified. These pollen and spores place the ore-hosting internal sediments and the Changdong paleo-karst at early to middle Oligocene. Consequently, the Changdong Pb-Zn deposit must have formed after the early Oligocene (∼34 Ma). These age constraints, together with the geological characteristics, indicate that the Changdong Pb-Zn deposit is a paleo-karst-controlled MVT deposit related to fold-thrust systems in the Sanjiang belt. The Changdong deposit is similar to other MVT Pb-Zn deposits in the northern part of the Sanjiang belt, making it possible to extend this Pb-Zn belt 500 km further to the South. Results presented here highlights the potential of sporopollens in dating the age of MVT deposits related to paleo-karst formation in young orogenic belts.

Background: Nitrogen- and water-use efficiency (NUE and WUE) reflect the capacity of plants to take up and utilize resources in the environments. Although N deposition and drought are known to affect plant growth and persistence, it remains elusive how plants adjust NUE, WUE and their relationship to adapt to the concurrent N deposition and drought under the context of global change. We conducted a field experiment in a temperate grassland in Inner Mongolia, in which N addition (10 g m–2yr−1), drought (reduced 66% precipitation during growing season) and their combination were manipulated, and we explored the responses of both instantaneous (NUEINSTand WUEINST) and long-term (NUELTand WUELT) WUE and NUE for six common plant species (Leymus chinensis, Stipa baicalensis, Thermopsis lanceolata, Potentilla bifurca, Thalictrum squarrosum, Klasea centauroide). Results: Across all the six species, NUEINSTdecreased and WUEINSTincreased with both N addition and drought; NUELTdecreased with both N addition and drought, while WUELTdecreased with N addition and increased with drought. A significant interactive effect between N addition and drought was detected, in that, drought weakened the negative effect of N addition on WUELTand NUELT, and N addition weakened the negative effect of drought on NUELT, but enhanced the positive effect of drought on WUELT. As a consequence, drought caused a trade-off between NUE and WUE, and N addition brought forth positive correlation between NUE and WUE. Meanwhile, the relationship between NUE and WUE varied among the species of different functional groups. Conclusions: Our study demonstrated that NUE, WUE and their relationship play an important role in determining their responses and adaptability to changes in soil nitrogen and water availability induced by N deposition and drought. Our results shed light on the antagonistic, synergetic and neutral effects between nitrogen deposition and drought on resource use efficiency, and further clarified the different adaptability among species of different functional groups, which will conduce to a comprehensive understanding on the role of NUE and WUE in plant persistence and coexistence in grassland ecosystems.

Gold nanoclusters have become promising radiosensitizers due to their ultrasmall size and robust ability to adsorb, scatter, and re-emit radiation. However, most of the previously reported gold nanocluster radiosensitizers do not have a precise atomic structure, causing difficulties in understanding the structure–activity relationship. In this study, a structurally defined gold–levonorgestrel nanocluster consisting of Au8(C21H27O2)8(Au8NC) with bright luminescence (58.7% quantum yield) and satisfactory biocompatibility was demonstrated as a nanoradiosensitizer. When the Au8NCs were irradiated with X-rays, they produced reactive oxygen species (ROS), resulting in irreversible cell apoptosis. As indicated by in vivotumor formation experiments, tumorigenicity was significantly suppressed after one radiotherapy treatment with the Au8NCs. In addition, compared with tumors treated with X-rays (4 Gy) alone, tumors treated with the nanosensitizer exhibited an inhibition rate of 74.2%. This study contributes to the development of atomically precise gold nanoclusters as efficient radiosensitizers.

The combination of gene therapy and immunotherapy has the potential to systemically promote anti-tumor effects while reducing adverse reactions. Small interfering RNA (siRNA) has generated great interest in biology, engineering and medicine, especially for cancer treatment due to its ability to knock down genes of interest. Nanomaterials play significant roles in the design of delivery systems of siRNA, and nanomaterial-mediated siRNA delivery in cancer immunotherapy is one of the most important directions for future clinical cancer treatment. Here, we review the recent advances in nanomaterial mediated targeted delivery of siRNA to dendritic cells (DCs), tumor-associated macrophages (TAMs), immune checkpoint inhibitors, B lymphocytes, natural killer cells (NKs), and immunosuppressive cytokines. Fundamental challenges in nucleic acid delivery enabled by bio-barriers, its promising solution strategies and future directions are also reviewed.

Gadolinium (Gd)-based compounds and materials are the most commonly used magnetic resonance imaging (MRI) contrast agents in the clinic; however, safety concerns associated with their toxicities in the free ionic form have promoted the development of new generations of metal-free contrast agents. Here we report a supramolecular strategy to convert an FDA-approved anticancer drug, Pemetrexed (Pem), to a molecular hydrogelator with inherent chemical exchange saturation transfer (CEST) MRI signals. The rationally designed drug–peptide conjugate can spontaneously associate into filamentous assemblies under physiological conditions and consequently form theranostic supramolecular hydrogels for injectable delivery. We demonstrated that the local delivery and distribution of Pem–peptide nanofiber hydrogels can be directly assessed using CEST MRI in a mouse glioma model. Our work lays out the foundation for the development of drug-constructed theranostic supramolecular materials with an inherent CEST MRI signal that enables noninvasive monitoring of their in vivodistribution and drug release.

Realizing “Power to Syngas” by electrifying chemical reactors via induction heating is one of the key enabling technologies to decarbonize the chemical industry. Nevertheless, developing catalysts for the induction heating process that can simultaneously serve as magnetic susceptors under high-temperature conditions remains challenging. Herein, we formulate a A-site vacancy induced electronic engineering strategy and, accordingly, synthesize a series of LaFe0.5Al0.5O3perovskite catalysts with different amounts of La vacancies (VLa) (LFAO, 1.5M-LFAO, and 3M-LFAO). In this way, we tune both the redox activity and the magnetocaloric effect (MCE) of perovskite and, for the first time, achieve induction heating methane partial oxidation coupled with CO2splitting for syngas production. Compared with the reported catalysts, the 3M-LFAO had not only superior syngas and CO yields (101.84L·kg cat-1/54.96Lkg cat-1) but also a great MCE (875°C). Spectroscopic investigations and DFT calculations rationalize these observations and demonstrate that the VLacause a unique Fe4+–O2-–Fe3+configuration in perovskite, accounting for an upshift of Fe 3d and O 2p band centers and therefore enhancing redox activity and MCE. This work deepens the understanding of the relationship between catalysis and MCE and unlocks the novel guidance to design induction heating chemical processes.

In order to utilize Overlay Tester to evaluate the crack resistance of Hot Mixture Asphalt (HMA) of steel deck pavement, three-dimensional finite element (FE) models of local steel deck pavement, composite beam and Overlay Tester specimen were established by Abaqus Software. The results show that the characteristic tensile stress in three FE models are similar, and the tensile stress of composite beam’s steel plate is much larger than that of composite beam’s HMA layer, hence the steel plate undergoes the major external force in the composite beam fatigue test, while the HMA layer seems not to be tested. To reduce this problem, FE models of Overlay Tester in three different displacements: 0.63mm, 0.063mm and 0.01mm, were analyzed. The results indicate that the stress in the 0.63mm displacement condition is much larger so that the asphalt mixture will be broken, and the stress in the 0.01mm displacement condition is similar to that of local steel deck pavement. In consideration of testing cycles and other factors, the 0.063mm displacement is recommended to test the HMA of steel deck pavement.

In order to solve the supporting problem of Wujiagou ore broken thick top-coal large sections coal roadway, in view of the mining geology and technology conditions, select the typical coal roadway 5106 tank and detect roof structure, detection results show that the major roof is coal, local contains feeble mudstone interlayer, shallow crack development, deep crack gradually reduce , then put forward the extra long bolt anchoring break top-coal to deep less fracture zone, and the theoretical calculation shows the feasibility and basic support parameters of using extra long bolt controlling deformation of coal roadway; Using FLAC numerical simulation method for different support scheme makes a comparative study, show that the extra long bolting effects obvious, and determined choosing extra long bolt + metal nets + W steel belt scheme. The site industrial test show that the extra long bolt + metal nets + W steel belt scheme supporting thick top-coal large sections of coal roadway effect is good.

Silver nanoparticles were synthesized by a sonochemistry method by using silver stearate and triphenylphosphine as silver precursor and reduction accelerator respectively. The experimental conditions that influence the formation and organization of the particles were investigated, and the particles were characterized by TEM. Results showed that well-ordered two-dimentional (2D)-monolayer was formed after solvent evaporation on a carbon-coated copper TEM grid at the optimal experimental conditions which was that the mole percentage of the amount of reducing agent and triphenylphosphine to silver precursor was 10% and 50% respectively, and the ultrasound power was set at 60% (relative to the maximum ultrasound power value of the machine).

After sulfur-plus-gold sensitization on silver bromoiodide (AgBr/I) microcrystal emulsions prepared by the emulsifying process in the double-jet apparatus controlled by a microcomputer, a certain amount of oxalate salt (1×10-1?1×10-2?1×10-3and 1×10-4mol/molAg) was respectively added at a specific time and pAg to a reactor to prepare a series of tabular silver bromoiodide (AgBr/I) microcrystal at whose surface oxalate ions and Ag2S or AuAgS were doped. The sensitometric results from these crystal emulsions showed: 1) that the sensitivities of oxalate-doped AgBr/I emulsion, relative to that of the undoped emulsion as the controlled one, were remarkably increased; 2) that a cooperative sensitization by oxalate dopant, sulfur-plus-gold was observed without any significant increase in fog level when 10-3—10-4 mol/molAg oxalate was doped;3) that sensitivity gain (SG) was maximal, when 10-3mol/molAg oxalate (in 10-1—10-4 mol/molAg ) was doped at the surface of AgBr/I grains.

Owing to their ability to rapidly proliferate in specific niches and their amenability to genetic manipulation, bacteria are frequently studied as potential diagnostic or therapeutic bioagents in a range of pathological contexts. A sustained oxygen supply within solid tumors is essential in order to achieve positive radiotherapy (RT) outcomes, as these intratumoral oxygen levels are necessary to facilitate RT‐induced reactive oxygen species (ROS) generation. In this study, a genetically engineered variant of the tumor‐targeting probiotic E. coli Nissle1917 bacteria that secret catalase is utilized to alleviate intratumoral hypoxia and to thereby enhance tumor radiosensitivity. These engineered bacteria are able to facilitate robust O2evolution and consequent ROS generation in response to X‐ray irradiation both in vitro and in vivo, significantly inhibiting tumor growth. Overall, the study highlights a novel and practical approach to enhance the efficacy of tumor RT, underscoring the value of future research in the field of probiotic medicine. In this study, a genetically engineered variant of the tumor‐targeting probiotic E. coliNissle 1917 bacteria that secrete catalase is utilized to alleviate intratumoral hypoxia and to thereby enhance tumor radiosensitivity. These engineered bacteria facilitate robust O2evolution and consequent reactive oxygen species generation in response to X‐ray irradiation both in vitro and in vivo, significantly inhibiting tumor growth.

The effects of the Cl2-based inductively coupled plasma (ICP) etching of GaN on the interface properties of Al2O3/GaN structures prepared by atomic layer deposition (ALD) were investigated. We used n-GaN layers grown on freestanding n+-GaN substrates with low dislocation density. The ICP etching caused slight disorder of the chemical bonds at the GaN surface and monolayer-level interface roughness at the Al2O3/GaN interface, resulting in poor capacitance--voltage ($C$--$V$) characteristics due to high-density interface states including nitrogen-vacancy (V\text{N) related levels. The postannealing process in N2at 400 °C drastically improved the $C$--$V$ characteristics, probably owing to the partial recovery of the V\text{N-related defects and the increased ordering of chemical bonds in the GaN surface region.

Acid‐mediated intramolecular Friedel—Crafts reaction of MBH adducts (III) and (VI) is studied.