Search

In recent years, the emergence of blaOXA-encoding Escherichia coli (E. coli) poses a significant threat to human health. Here, we systematically analyzed the global geographic distribution and genetic characteristics of 328 blaOXA-positive E. coli plasmids based on NCBI database. Twelve blaOXA variants have been discovered, with blaOXA−1 (57.93%) being the most common, followed by blaOXA−10 (11.28%) and blaOXA−48 (10.67%). Our results suggested that blaOXA-positive E. coli plasmids were widespread in 40 countries, mainly in China, the United States, and Spain. MLST analysis showed that ST2, ST43, and ST471 were the top three host STs for blaOXA-positive plasmids, deserving continuing attention in future surveillance program. Network analysis revealed a correlation between different blaOXA variants and specific antibiotic resistance genes, such as blaOXA−1 and aac (6')-Ib-cr (95.79%), blaOXA−181 and qnrS1 (87.88%). The frequent detection of aminoglycosides-, carbapenems- and even colistin-related resistance genes in blaOXA-positive plasmids highlights their multidrug-resistant potential. Additionally, blaOXA-positive plasmids were further divided into eight clades, clade I-VIII. Each clade displayed specificity in replicon types and conjugative transfer elements. Different blaOXA variants were associated with specific plasmid lineages, such as blaOXA−1 and IncFII plasmids in clade II, and blaOXA−48 and IncL plasmids in clade I. Overall, our findings provide a comprehensive insight into blaOXA-positive plasmids in E. coli, highlighting the role of plasmids in blaOXA dissemination in E. coli. [ABSTRACT FROM AUTHOR]

Micro-energy network systems make full use of renewable energy and reduce dependence on external power grids, which is of great significance for enhancing the reliability of regional energy systems. Since it needs various energy production equipment to meet multiple energy demands, achieving optimal operation is the key to a successful micro-energy network system. This research is based on an industrial park in China, where we optimize the micro-energy network system to minimize the economic cost, environmental impact, and carbon emissions. Life cycle assessment is used to calculate the environmental impact and carbon emissions, and a multi-objective optimization model is constructed to which the NSGA-II is applied. The results show that in the comprehensive optimization scenario, the environmental impact is reduced by 34.0–67.3%, the economic cost is increased by 3.6–5.2%, and carbon emissions reduced by 10.2–24.3%. Findings from this study suggest that the capacity of solar photovoltaic and light pipes should be expanded by 100% and 50% and that gas turbine units and air source heat pumps should be added for power generation and winter heating. This would reduce reliance on the power grid, increase stability, and realize structural optimization of the micro-energy network systems. [ABSTRACT FROM AUTHOR]

XRD diffraction scanning tests were utilized to determine rock mineral composition, and a numerical calculation model of heterogeneous granite was established utilizing the PFC. The macro and micro damage characteristics of the heterogeneous granite model were analyzed. During failure, the boundary energy, strain energy, and dissipation energy were monitored. The results indicates that confining pressure can enhance the elastic modulus of the model by approximately 1.5 times. Under non-confining pressure conditions, shear failure is dominant in the model. Conversely, under confining pressure conditions, tensile-shear composite failure is prevalent. The micro-failure types are mainly slippage failure and shear failure. The microstructural strength of Albite and Quartz is found to increase with rising confining pressure, whereas that of Kaolinite is inhibited. Confining pressure has little effect on the microstructural strength of Potassium Feldspar. The critical confining pressure for the model is determined to be 15 MPa; strain energy is the dominant energy component at pressures below this threshold, while dissipation energy become dominant above it. At the micro-level, the boundary energy in the crack initiation energy is more sensitive to the confining pressure. In the peak strength energy, the growth rate of strain energy is greater than that of dissipation energy. [ABSTRACT FROM AUTHOR]

Purpose: Triple-negative breast cancer (TNBC) features high aggressiveness, metastasis rate, drug resistance as well as poor prognosis. Osteopontin (OPN) is a key protein in the process of osteogenesis and has emerged as a new tumor marker in recent years. Methods: Cell viability was tested with the CCK-8 kit. Transwell and wound healing were adopted to test cell invasive and migratory abilities. Tumor sphere formation was detected by tumor sphere formation assay. Human umbilical vein endothelial cell (HUVEC) tube formation assay was used to measure the angiogenesis of tumor cells. Western blot was applied for the estimation of the expression of cancer stem cell markers, angiogenesis-, signaling pathway-related proteins as well as OPN. Bioinformatics tools predicted OPN expression in breast cancer tissues. The levels of oxidative stress-related markers were assessed with ELISA. Following the overexpression of OPN in MD-MB-436 cells and the addition of the PI3K/AKT/mTOR pathway inhibitor LY294002, the aforementioned functional experiments were implemented again to investigate the mechanism. Finally, in vivo experiments of tumor-bearing mice were performed for further verification. Results: The proliferative, invasive, migratory and tumor sphere formation capabilities as well as angiogenesis of TNBC cells were conspicuously increased in contrast to non-TNBC cell lines. OPN expression in TNBC tissues and cells was dramatically enhanced. OPN upregulation significantly elevated cell proliferative, invasive and migratory capabilities as well as tumor sphere formation and angiogenesis. The mechanism might be achieved by activating PI3K/AKT/mTOR signaling to regulate glutathione peroxidase 4 (GPX4)-mediated anti-lipid peroxidation. Conclusion: OPN promoted tumor sphere formation and angiogenesis in TNBC by activating the PI3K/AKT/mTOR pathway to regulate GPX4-mediated anti-lipid peroxidation levels. [ABSTRACT FROM AUTHOR]

Acetamiprid (ACE) is a highly effective broad-spectrum insecticide, and its widespread use is potentially harmful to human health and environmental safety. In this study, magnetic Fe3O4/carbon (Fe3O4/C), a derivative of metal–organic framework MIL-101 (Fe), was synthesized by a two-step calcination method. And a fluorescent sensing strategy was developed for the efficient and sensitive detection of ACE using Fe3O4/C and multiple complementary single-stranded DNA (ssDNA). By using aptamer with multiple complementary ssDNA, the immunity of interference of the aptasensor was improved, and the aptasensor showed high selectivity and sensitivity. When ACE was present, the aptamer (Apt) combined with ACE. The complementary strand of Apt (Cs1) combined with two short complementary strands of Cs1, fluorophore 6-carboxyfluorescein-labeled complementary strand (Cs2-FAM) and the other strand Cs3. The three strands formed a double-stranded structure, and fluorescence would not be quenched by Fe3O4/C. In the absence of ACE, Cs2-FAM would be in a single-chain state and would be adsorbed by Fe3O4/C, and the fluorescence of FAM would be quenched by Fe3O4/C via photoelectron transfer. This aptasensor sensitively detected ACE over a linear concentration range of 10–1000 nM with a limit of detection of 3.41 nM. The recoveries of ACE spiked in cabbage and celery samples ranged from 89.49% to 110.76% with high accuracy. [ABSTRACT FROM AUTHOR]

Installing photovoltaic (PV) systems is an essential step for low-carbon development. The economics of PV systems are strongly impacted by the electricity price and the shadowing effect from neighboring buildings. This study evaluates the PV generation potential and economics of 20 cities in China under three shadowing conditions. First, the building geometry models under three shadowing conditions for the 20 cities were constructed using QGIS. Then, 60 building models with PV systems and shadows from surrounding buildings were generated by City Buildings, Energy, and Sustainability (CityBES), an open platform, to simulate the PV power generation. Finally, the study presented one economic analysis model to evaluate the profitability by combining the market cost of rooftop PV systems and electricity prices in China. The economic model included four indicators: payback period (static and dynamic), net present value (NPV), and internal rate of return (IRR). The results show that the reduction of PV power generation ranges from 8.29% to 16.01% under medium shadowing, and experiences a maximum decrease of up to 39.71% under high shadowing. Further economic analysis shows that almost all the regions show reliable potential, obtaining an IRR higher than the reference value (5%). Nenjiang has the highest economic profit, with the highest NPV (86,181.15 RMB) and IRR (30.14%) under no shadowing among 20 cities. It also should be mentioned that the alignment between electricity price distribution and the solar power generation curve will directly impact the economic potential of PV systems. [ABSTRACT FROM AUTHOR]

An unsophisticated fluorescence-enabled strategy is brought forward to process the highly sensitive fluorescence detection of Salmonella typhimurium (S. typhimurium) which based on polyethyleneimine (PEI)-templated silver/copper nanoclusters (Ag/CuNCs) (λ excitation = 334 nm and λ emission = 466 nm) with cryonase-assisted target recycling amplification. The Ag/CuNCs nanoclusters are synthesized as fluorescent materials due to their strong and stable fluorescence characteristics and are modified with S. typhimurium aptamers to form aptamer-Ag/CuNCs probes. The probes can be adsorbed on the surface of quenching agents-polydopamine nanospheres (PDANSs), thereby inducing fluorescence quenching of the probes. Once the aptamers are bound to the target, the aptamers/targets complexes are separated from the PDANSs surface, and the Ag/CuNCs recover the fluorescence signal. The released complexes will immediately be transformed into a substrate digested by cryonase (an enzyme that can digest all types of nucleic acids), and the released targets are bound to another aptamers to initiate the next round of cleavage. This reaction will be repeated continuously until all relevant aptamers are consumed and all Ag/CuNCs are released, resulting in a significant amplification of the fluorescence signal and improved sensitivity. Using Ag/CuNCs as fluorescent probes combined with cryonase-assisted amplification strategy, the fluorescence aptasensor is constructed with detection limits as low as 3.8 CFU mL−1, which is tenfold better than without the cryonase assistance. The method developed has been applied to milk, orange juice, chicken, and egg white samples with excellent selectivity and accuracy providing an approach for the early and rapid detection of S. typhimurium in food. [ABSTRACT FROM AUTHOR]

Cytokinin oxidase/dehydrogenase (CKX) is a key regulatory enzyme for the irreversible degradation of the plant hormone cytokinin (CK), which is important in growth and development and response to abiotic stresses in cotton. In this study, 27, 28, 14 and 14 CKXs were screened by FAD structural domain and cytokinin binding structural domain in Gossypium hirsutum, Gossypium barbadense, Gossypium arboreum and Gossypium raimondii, respectively. Their phylogenetic relationships and expression patterns were analyzed, and most GhCKXs were found to be tissue-specific and responsive to various abiotic stresses such as cold, heat, salt and PEG. GhCKX6b-Dt was selected for gene silencing in evolutionary branch II for salt stress, because its expression increased after salt stress in cotton plants. An increase in PRO and MDA content and a decrease in SOD activity due to this gene were found after inducing salt stress, contributing to oxidative damage and decreased salt tolerance. In this study, CKXs were analyzed to reveal the possible role of GhCKXs against abiotic stresses in cotton, which provides a basis for further understanding of the biological functions of CK in plants such as growth and development and stress resistance. [ABSTRACT FROM AUTHOR]

Sponge-based materials have attracted wide attention because of their low cost, easy to manufacture and environmental-friendly. Sponge-based materials have the characteristics of large porosity and large specific surface area, which make sponge-based materials both lipophilic and hydrophilic, so it is necessary to modify the surface of sponge-based materials. The sponge-based material can obtain superhydrophobic properties while maintaining high porosity and large specific surface area. The superhydrophobic properties of sponge-based materials were obtained by reducing material surface energy and constructing surface rough structure. In this paper, four common surface modified materials are reviewed, which are polydopamine, organosilicons, carbon-based material and stearic acid. In order to improve the working efficiency of superhydrophobic sponge. The superhydrophobic sponge has certain functionality by adding special nanoparticles or functional materials in the process of superhydrophobic modification, such as magnetism, photocatalysis, flame retardancy and antibacterial. Functionalization enables the superhydrophobic sponge to obtain controllability, self-cleaning ability, thermal stability and anti-corrosion ability. We reviewed the hydrophobic and oil absorption abilities of different modified superhydrophobic sponges, and summarized the stability of sponges under the conditions of strong acid, strong alkali and extrusion cycle. Furthermore, the future development of superhydrophobic sponge is prospected. [ABSTRACT FROM AUTHOR]

The Yellow River is an important ecological shelter zone and economic belt in China. However, rapid urbanization and industrialization has produced a fragile ecological environment conditions and unbalanced economic development in the Yellow River Basin (YRB). Ecological protection and high-quality development of the YRB has been China's national strategy since 2019. As the only coastal province with the largest economy and population in the YRB, the sustainable development of Shandong Province is of great importance in the region. This study evaluated the dynamic trend of sustainability levels of the nine cities in Shandong Province in the YRB through emergy analysis. Emergy-based indicators were established and analyzed from 2010 to 2019, taking account of the ecological service emergy (ESE) needed to dilute pollutants and emergy equivalent loss (EEL) on ecosystem quality and human health damage. Results showed that emergy sustainable indicators (ESI) in Tai'an, Heze, Dezhou, and Liaocheng ranged from 1 to 10, which had the potential for sustainable development. The ESI value of Jinan, Jining, Zibo, Dongying, and Binzhou was less than 1, which indicated that these cities were under great ecological pressure. The value of emergy indicators for sustainable development (EISD) of the nine cities all declined from 2010 to 2016, but remained stable from 2017 to 2019. Based on findings from the emergy analysis regarding policy implications and local conditions, the study concludes by providing proposals to improve regional sustainability. [ABSTRACT FROM AUTHOR]

The sustainable development of agriculture is facing problems such as high resource consumption and serious environmental pollution. The development of the circular economy model integrating planting and breeding (CEMIPB) has become an effective way to realize the sustainable development of agriculture. Due to the great difference of natural resource attributes in different regions of China, CEMIPB shows diverse characteristics on the whole. Based on this, this paper constructs a coupling model based on emergy analysis (EMA) and life cycle assessment (LCA) called EM-LCA model and conducts an empirical analysis using a typical CEMIPB in Fujian Province, China, as a case. By comparing the results of the EM-LCA and EMA models, the former effectively compensates for the deficiencies of the latter in terms of economic and environmental impact assessment, and the evaluation results can better reflect the actual situation of the system. Furthermore, sensitivity analysis is introduced to identify key processes and substances. Based on the reduce–reuse–recycle (3R) principle, several optimization suggestions, such as reducing the input of corn and veterinary drugs, are put forward. The construction of the aforementioned methodology system can provide a new perspective for research in similar fields and provide a scientific basis for local government decision making. [ABSTRACT FROM AUTHOR]

Malignant melanoma, an increasingly common form of skin cancer, poses a significant threat to public health, especially when the disease progresses past skin lesions to the stage of advanced metastasis. In this work, a new anti-tumor peptide, temporin La (T-La), was selected from a cDNA library generated from bullfrog skin. Two new derivative antitumor peptides, T-La (S) and T-La (FS), were designed by bioinformatics analysis and coupled with the RGD small molecule peptide to create chimeric RGD peptides, (RGD-T-La [S] and RGD-T-La [FS]). Preliminary experiments showed that the new antitumor peptides had significant antitumor effects. After coupling to the chimeric RGD peptide, the targeted treatment of mouse melanoma was significantly improved. Our data demonstrate that the 4 peptides tested herein significantly inhibited the proliferation, migration, and invasion of B16F10 cells; with an increase in polypeptide concentration, the proportion of melanoma cells in the G0/G1 phase decreased or increased significantly, respectively, the reactive oxygen species (ROS) content increased significantly, the mitochondrial membrane potential decreased significantly, and the expression of pro-apoptotic Bax, Caspase-3, and Caspase-9 increased, and anti-apoptotic Bcl-2 decreased significantly. Tyr and MITF genes were significantly downregulated. In conclusion, the use of these new anti-tumor peptides, when combined with a chimeric RGD peptide, may increase ROS levels and decrease mitochondrial membrane potential by inhibiting the activity of mitochondria, thus releasing apoptosis-promoting factors in B16F10 cells. The present study describes a new potential strategy for the application of promising peptides in the treatment of various cancers. [ABSTRACT FROM AUTHOR]