163 research outputs found
Enrofloxacin Induces Intestinal Microbiota-Mediated Immunosuppression in Zebrafish
The immunosuppressive effects of antibiotics and the potential associations with the intestinal microbiota of the host have been increasingly recognized in recent years. However, the detailed underlying mechanisms of immune interference of antibiotics in environmental organisms remain unclear, particularly at the early life stage of high sensitivity. To better understand the gut microbiome and immune function interactions, the vertebrate model, zebrafish, was treated with environmentally relevant concentrations of a frequently detected antibiotic, enrofloxacin (ENR), ranging from 0.01 to 100 μg/L. 16S ribosomal RNA sequencing indicated diminished diversity, richness, and evenness of intestinal flora following ENR treatment. Twenty-two taxa of gut bacteria including Rickettsiales, Pseudomonadales, and Flavobacteriales were significantly correlated with immunosuppressive biomarkers, including a significant decrease in the abundance of macrophages and neutrophils. To validate the immunomodulatory effects due to altered intestinal microbial populations, zebrafish reared under sterile and non-sterile husbandry conditions were compared after ENR treatment. A significant inhibitory effect was induced by ENR treatment under non-sterile conditions, while the number of macrophages and neutrophils, as well as biomarkers of immunosuppressive effects, were significantly salved in zebrafish under sterile conditions, confirming for the first time that immunosuppression by ENR was closely mediated through alterations of the intestinal microbiome in fish.publishedVersio
Exogenous leucine alleviates heat stress and improves saponin synthesis in Panax notoginseng by improving antioxidant capacity and maintaining metabolic homeostasis
Panax notoginseng saponins (PNSs) are used as industrial raw materials to produce many drugs to treat cardio-cerebrovascular diseases. However, it is a heat-sensitive plant, and its large-scale artificial cultivation is impeded by high temperature stress, leading to decreases in productivity and PNSs yield. Here, we examined exogenous foliar leucine to alleviate heat stress and explored the underlying mechanism using metabolomics. The results indicated that 3 and 5 mM exogenous foliar leucine significantly alleviated heat stress in one-year- and two-year-old P. notoginseng in pots and field trials. Exogenous foliar leucine enhanced the antioxidant capacity by increasing the activities of antioxidant enzymes (POD, SOD) and the contents of antioxidant metabolites (amino acids). Moreover, exogenous foliar leucine enhanced carbohydrate metabolism, including sugars (sucrose, maltose) and TCA cycle metabolites (citric acid, aconitic acid, succinic acid and fumaric acid), in P. notoginseng leaves, stems, and fibrous roots to improve the energy supply of plants and further alleviate heat stress. Field experiments further verified that exogenous foliar leucine increased the productivity and PNSs accumulation in P. notoginseng. These results suggest that leucine application is beneficial for improving the growth and quality of P. notoginseng under heat stress. It is therefore possible to develop plant growth regulators based on leucine to improve the heat resistance of P. notoginseng and other crops
The associations of residential greenness with fetal growth in utero and birth weight: A birth cohort study in Beijing, China
Background: Although studies have examined the association between residential greenness and birth weight, there is no evidence regarding the association between residential greenness and fetal growth in utero. We aimed to investigate the associations of residential greenness with both fetal growth in utero and birth weight. Methods: A birth cohort (2014–2017) with 18,665 singleton pregnancies was established in Tongzhou Maternal and Child hospital of Beijing, China. Residential greenness was matched with maternal residential address and estimated from remote satellite data using normalized difference vegetation index with 200 m and 500 m buffers (NDVI-200 and NDVI-500). Fetal parameters including estimated fetal weight (EFW), abdominal circumference (AC), head circumference (HC) an
Crop Diversity for Yield Increase
Traditional farming practices suggest that cultivation of a mixture of crop species in the same field through temporal and spatial management may be advantageous in boosting yields and preventing disease, but evidence from large-scale field testing is limited. Increasing crop diversity through intercropping addresses the problem of increasing land utilization and crop productivity. In collaboration with farmers and extension personnel, we tested intercropping of tobacco, maize, sugarcane, potato, wheat and broad bean – either by relay cropping or by mixing crop species based on differences in their heights, and practiced these patterns on 15,302 hectares in ten counties in Yunnan Province, China. The results of observation plots within these areas showed that some combinations increased crop yields for the same season between 33.2 and 84.7% and reached a land equivalent ratio (LER) of between 1.31 and 1.84. This approach can be easily applied in developing countries, which is crucial in face of dwindling arable land and increasing food demand
Qwen Technical Report
Large language models (LLMs) have revolutionized the field of artificial
intelligence, enabling natural language processing tasks that were previously
thought to be exclusive to humans. In this work, we introduce Qwen, the first
installment of our large language model series. Qwen is a comprehensive
language model series that encompasses distinct models with varying parameter
counts. It includes Qwen, the base pretrained language models, and Qwen-Chat,
the chat models finetuned with human alignment techniques. The base language
models consistently demonstrate superior performance across a multitude of
downstream tasks, and the chat models, particularly those trained using
Reinforcement Learning from Human Feedback (RLHF), are highly competitive. The
chat models possess advanced tool-use and planning capabilities for creating
agent applications, showcasing impressive performance even when compared to
bigger models on complex tasks like utilizing a code interpreter. Furthermore,
we have developed coding-specialized models, Code-Qwen and Code-Qwen-Chat, as
well as mathematics-focused models, Math-Qwen-Chat, which are built upon base
language models. These models demonstrate significantly improved performance in
comparison with open-source models, and slightly fall behind the proprietary
models.Comment: 59 pages, 5 figure
Revealing the superior corrosion protection of the passive film on selective laser melted 316L SS in a phosphate-buffered saline solution
This study investigated the passivation behaviour of wrought 316L stainless steel (SS) and 316L manufactured by the Selective Laser Melting (SLM) process in phosphate-buffered saline (PBS). The 3D printing laser power influenced microstructure, passive film and corrosion resistance of SLM 316L SS were studied, and compared with the results of wrought 316L SS. The results indicated that a smaller corrosion current density and improved breakdown potential (Eb) of SLM 316L SS was associated with a higher proportion of Cr2O3 in the passive film at OCP conditions. The Transmission Electron Microscopy (TEM) proved that the passive film on SLM 316L SS was continuous and compact at 600 mV vs. Ag/AgCl applied potential. The increase in the applied potential resulted in a high content of hydroxide being recorded in the passive film. The results also suggest preferential facets of (1 1 0) and abundant grain/sub-grain boundaries for SLM 316L SS, as well as the increased work of separation and growth rate of the passive film from the substrate. Wrought 316L SS demonstrated preferred facets of (1 1 1)-γ and larger grains. There are confirmed via X-Ray Diffraction (XRD), Electron Backscatter Diffraction (EBSD) and the first-principle calculation
Numerical study failure characteristics of natural fracture under induced stress
Hydraulic fracturing is an effective method for developing oil and gas in unconventional reservoirs. The openings of natural fractures directly affect the complexity of the fracture body. The failure characteristics of natural fractures are critical factors in determining their activation by hydraulic fractures. Based on the three-dimensional displacement discontinuity method, a three-dimensional mechanical model of the interaction between hydraulic and natural fractures was established. Based on the shear and tensile failure criteria of the natural fractures, the failure characteristics of different natural fractures were clarified. Research has shown that the failure characteristics of natural fractures are influenced by factors such as three-dimensional stress, spatial distribution, and roughness. After the hydraulic fractures pass through the natural fractures, tensile and shear failures occur simultaneously; the failure of natural fractures is primarily affected by their strike and dip angles. During the process of hydraulic fracture approximation, the shear stress increases as the distance between the hydraulic fracture tip and natural fracture decreases. When the strike angle of the natural fractures near the tips of the hydraulic fractures was greater than 35°, the stress became consistent. As the dip angle of the natural fractures increased, the lowest point of the shear stress gradually moved from the upper to the lower half. This research studies the tensile and shear failure of natural fractures under different conditions, in order to facilitate engineering judgment of the types and characteristics of natural fracture failure. It is of great significance for us to understand the formation mechanism of complex fracture network morphology in volume fracturing
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