Publications

Salmonella is one of the most common foodborne pathogens in the world, and Salmonella typhimurium, the most frequently isolated serotype, can cause zoonosis. In this study, we evaluated the effect of glucose concentration on the biofilm formation of 11 strains of Salmonella typhimurium. We found that among the selected strains, low-sugar conditions were more conducive to the formation of biofilms, although strain ST19 followed another rule. As the glucose concentration increased, biofilm formation showed an increasing trend. When the concentration of glucose reached 1.5%, other strains no longer formed biofilms, while strain ST19 still had strong biofilm formation ability. Therefore, we selected a culture medium containing 1.5% glucose to collect biofilms and planktonic cells of strain ST19 and compared them with strain CDC3, which did not produce a biofilm under these conditions, for transcriptomics analysis. The results showed that the related genes in the phosphotransferase system (PTS) and the operon genes regulated by AI-2 signaling molecules were highly downregulated in the biofilm bacteria of strain ST19 with a glucose content of 1.5%. At the same time, the genes involved in the two-component system, carbon metabolism and transcription regulation were significantly upregulated, which indicated that strain ST19 could adapt to a high-glucose environment by regulating glucose transport and metabolism in bacteria under a high-glucose environment and regulate biofilm formation by upregulating the expression of related genes in the two-component system. These findings illustrated that the regulated mechanism of Salmonella typhimurium's biofilm formation, which are significant to control biofilm contamination.

(1) Background: Wood decay is a serious issue that results from the presence of wood-destroying fungi and has a great influence on the international wood industry. The utilization of biological control methods offers good prospects for wood preservation. (2) Methods: The plate-screening experiment, the soil block test of the Chinese stand method (GB/T 13942.1), and the characterization of wood blocks were used to achieve biological control of brown rot and white rot. (3) Results: Through isolation, screening, and identification, the antagonistic bacterium Bacillus velezensis Nhw-B72 strain was obtained. In the plate-screening experiment, the inhibition zone diameter of Nhw-B72 for Gloeophyllum trabeum was 1.68 cm and that for Coriolus versicolor was 2.33 cm. After inhibition, the morphology of mycelia was distorted, malformed, and broken. In the soil block test, the average weight loss percentage of wood blocks in the control group was 61.66%. In the treatment group, the average weight loss percentage of the wood blocks with drying was 28.18% and that of the wood blocks without drying was 34.97%. (4) Conclusions: The strain has an obvious antagonistic effect on the wood-destroying fungi and the sterile fermentative liquid can effectively inhibit wood decay. In addition, compared to the drying of wood blocks, the air-drying of blocks after impregnation with the fermentative liquid had a better inhibition effect.

Overexpression of folate receptor alpha (FRα) and high telomerase activity are considered to be the characteristics of ovarian cancers. In this study, we developed FRα-targeted lipoplexes loaded with an hTERT promoter-regulated plasmid that encodes a matrix protein (MP) of the vesicular stomatitis virus, F-LP/pMP (2.5) , for application in ovarian cancer treatment. We first characterized the pharmaceutical properties of F-LP/pMP (2.5) . The efficient expression of the MP-driven hTERT promoter in SKOV-3 cells was determined after an in-vitro transfection assay, which was significantly increased compared with a non-modified LP/pMP (2.5) group. F-LP/pMP (2.5) treatment significantly inhibited the growth of tumors and extended the survival of mice in a SKOV-3 tumor model compared with other groups. Such an anti-tumor effect was due to the increased expression of MP in tumor tissue, which led to the induction of tumor cell apoptosis, inhibition of tumor cell proliferation and suppression of tumor angiogenesis. Furthermore, a preliminary safety evaluation demonstrated a good safety profile of F-LP/pMP (2.5) as a gene therapy agent. Therefore, FRα-targeted lipoplexes with therapeutic gene expression regulated by an hTERT promoter might be a promising gene therapy agent and a potential translational candidate for the clinical treatment of ovarian cancer.

The acquisition of high-quality tree point cloud datasets facilitates research in various forestry fields, including tree species classification, diversity monitoring, and biomass estimation. However, due to limitations in sensor performance and occlusion between trees, tree point clouds acquired using LiDAR scanners often exhibit missing data. This not only degrades the quality of the point clouds, but also significantly reduces the number of usable samples. Therefore, this study proposed a tree point cloud enhancement system, which included the completion network and the sample augmentation network. The point cloud completion network utilized a transformer-based improved module to predict missing point clouds and combined up-sampling processing to progressively complete the point clouds from coarse to fine. This could improve the subsequent model decisions and performance through data balancing. On the other hand, the sample augmentation network, based on an adversarial learning strategy, separately constructed the generator and the classifier. By applying shape transformations, point displacements, and point drop to complete point cloud samples, the learnable parameters in the generator and the classifier were alternately optimized. This process enhanced both the quality and the quantity of the tree point cloud dataset. In addition, this study introduced a multi-head attention pooling layer, which further enhanced the joint network’s ability to learn and extract tree structural features. The experimental results showed that the completion network successfully restored missing tree point clouds of various types, achieving an average Chamfer Distance of 4.84 and an average F-score of 0.90. The experiments also demonstrated the effectiveness and robustness of the sample augmentation network, which improved classification accuracy by approximately 2.9% compared to the original dataset.

The quality of traditional Chinese medicine (TCM) guarantees its clinical efficacy. Although advanced analytical techniques and methods can accurately determine the content of chemical components in TCM, it is difficult to accurately determine its clinical efficacy. In addition, the current analytical methods and technologies are complex and have difficulty meeting the requirements of a rapid, accurate and convenient determination of TCM quality. In this study, we first propose the concept of “indistinct” evaluation of the quality of TCM, that is, combining biological potency with character evaluation, quantifying the character evaluation, and preparing the safflower quality grade evaluation card based on the character analysis, which provides research ideas and methods for the rapid and accurate evaluation of the quality of TCM. We determined the biological potency of different batches of safflower based on the in vitro antiplatelet aggregation model and divided the safflower samples into two grades based on the biological potency. We further collected the color information of different grades of safflower samples, quantified the color information of different grades of safflower, drew a quality grade evaluation card for the rapid judgment of safflower quality grade and verified its accuracy by pharmacodynamic evaluation. To further analyze the differences in the material basis of different grades of safflower, the LC-MS method was used to simultaneously determine the contents of 19 chemical components, such as myricetin, in different grades of safflower samples to analyze the differences in the material basis of different grades of safflower. The result shows that the different grades of safflower exhibited significant differences in color. The pharmacodynamic results show that the quality evaluation card prepared based on color information can accurately evaluate quality, and the effect of first-class safflower is significantly better than that of second-class safflower. The chemical analysis results of different grades of safflower show that there are also significant differences between them, among which hypericin, 6-hydroxyapin-6-O-glucose-7-O-glucuronide, 6-hydroxykaempferol-3,6-O-diglucoside-7-O-glucuronic acid glycoside, 6-hydroxykaempferol-3,6,7-tri-O-glucoside and hydroxysafflower yellow A exhibit significant differences, which may be the main differentiating components of different grades of safflower. This study preliminarily confirmed that the “indistinct” evaluation of the quality of TCM based on character analysis is accurate and scientific, and the quality evaluation card prepared can accurately judge the quality of TCM, providing a reference for the rapid application of TCM character evaluation.

The enhanced mutualism hypothesis postulates that invasive plants promote self-growth by enriching beneficial microbes to establish a positive soil feedback. However, the roles of soil microorganisms may vary with increasing time for plant growth. Research on changes in soil microbial communities over time has important implications for understanding the mechanisms underlying plant invasion. Due to the difficulty in evaluating the duration of plant growth, few studies have quantified the changes in soil microorganisms with increasing plant age. This study focuses on the invasive weed Phytolacca americana L., which has growth rings in the main root. We conducted a two-stage experiment in the field and greenhouse to explore the soil feedback changes with duration of plant growth. We determined the effects of P. americana at different ages on the soil microbial community and soil properties and performed a soil inoculation experiment to quantify the influence of soil microbes on seed germination and seedling performance. We found that the content of some soil nutrients, namely total nitrogen, total phosphorus, nitrate-N, and available phosphorus, significantly decreased with increasing growth age of P. americana, whereas the available potassium showed an opposite increasing trend. The P. americana growth age also significantly influenced the soil bacterial community structure. However, this phenomenon did not occur in the fungal community. In the bacterial community, the relative abundance of plant growth-promoting bacteria showed an increasing trend. The soil inoculation experiment had high seed germination rates and biomass accumulation when the plants were grown in conditioned soil from P. americana growth within 5 years, suggesting a positive plant-soil feedback. However, the promoting effect disappeared in conditioned soil from 10 years of age. Our findings demonstrate that plant growth-promoting bacteria significantly accumulated in the soil during the early stages of P. americana invasion, and that the strength of enhanced positive feedback may play a crucial role in facilitating P. americana invasion. This study highlights the changing nature of plant-microbe interactions during biological invasion and illustrates how bacteria could contribute to the initial success of P. americana, providing new insights into the underlying mechanisms of plant invasion.

Bacteria can elaborate complex patterns of development that are dictated by temporally ordered patterns of gene expression, typically under the control of a master regulatory pathway. For some processes, such as biofilm development, regulators that initiate the process have been identified but subsequent phenotypic changes such as stress tolerance do not seem to be under the control of these same regulators. A hallmark feature of biofilms is growth within a self-produced extracellular matrix. In this study we used metabolomics to compare Salmonella cells in rdar colony biofilms to isogenic csgD deletion mutants that do not produce an extracellular matrix. The two populations show distinct metabolite profiles. Even though CsgD controls only extracellular matrix production, metabolite signatures associated with cellular adaptations associated with stress tolerances were present in the wild type but not the mutant cells. To further explore these differences we examine the temporal gene expression of genes implicated in biofilm development and stress adaptations. In wild type cells, genes involved in a metabolic shift to gluconeogenesis and various stress-resistance pathways exhibited an ordered expression profile timed with multicellular development even though they are not CsgD regulated. In csgD mutant cells, the ordered expression was lost. We conclude that the induction of these pathways results from production of, and growth within, a self produced matrix rather than elaboration of a defined genetic program. These results predict that common physiological properties of biofilms are induced independently of regulatory pathways that initiate biofilm formation.

The binding of therapeutic antagonists to their receptors often fail to translate into adequate manipulation of downstream pathways. To fix this ‘bug’, here we report a strategy that stitches cell surface ‘patches’ to promote receptor clustering, thereby synchronizing subsequent mechano-transduction. The “patches” are sewn with two interactable nanothreads. In sequence, Nanothread-1 strings together adjacent receptors while presenting decoy receptors. Nanothread-2 then targets these decoys multivalently, intertwining with Nanothread-1 into a coiled-coil supramolecular network. This stepwise actuation clusters an extensive vicinity of receptors, integrating mechano-transduction to disrupt signal transmission. When applied to antagonize chemokine receptors CXCR4 expressed in metastatic breast cancer of female mice, this strategy elicits and consolidates multiple events, including interception of metastatic cascade, reversal of immunosuppression, and potentiation of photodynamic immunotherapy, reducing the metastatic burden. Collectively, our work provides a generalizable tool to spatially rearrange cell-surface receptors to improve therapeutic outcomes.