In recent years, potato scab caused by Streptomyces scabies is aggravating year by year, becoming an industrial problem urgently to be resolved. Screening antagonistic bacteria with good inhibitory effect and wide adaptability is the main measure to realize effective prevention and control of the disease. This study screened three strains of antagonistic bacteria DXT2-4, T2-1 and 21-14 with good inhibitory effect on S. scabies by using plate standoff test, and identified them as Bacillus altitudinis, Bacillus safensis and Bacillus pumilus, respectively, based on morphological characteristics, physiological and biochemical properties, and 16S rRNA gene sequences. DXT2-4, T2-1 and 21-14 showed the pot control efficacy of 68.83%, 48.57%, and 57.14%, respectively. The field control efficacy of the three strains was 59.48%, 34.58% and 51.75% in Hulun Buir, Inner Mongolia Autonomous Region and 55.14%, 36.05%, and 49.05% in Huizhou, Guangdong. The three strains could grow normally in the media with pH 1.0-13.0 and with 1%-11% NaCl, and they had inhibitory effects on Rhizoctonia solani, Verticillium dahliae, Alternaria solani, and Fusarium oxysporum. The indole-3-acetic acid yields of DXT2-4, T2-1, and 21-14 were 2.23, 1.11, and 1.67 mg/L, respectively. DXT2-4 and 21-14 demonstrated strong abilities to solubilize phosphorus. The optimal carbon source, nitrogen source, and inorganic salt for fermentation of strain DXT2-4 were 2% molasses+2% corn starch, 2% soybean meal, and 0.3% MgSO₄·7H₂O, respectively. These findings suggest the three strains of bacteria can efficiently inhibit the growth of S. scabies and have strong environmental adaptability. Particularly, DXT2-4 has the best effects of inhibiting the disease and promoting plant growth, showing a high development value and broad application prospects, this is of great significance for promoting sustainable potato production and ensuring the environmentally sound utilization of resources.
Streptomyces/metabolism* ; Fermentation ; Plant Diseases/prevention & control* ; Solanum tuberosum/growth & development* ; Bacillus/growth & development* ; Antibiosis

Objective : To observe the effect of Celastrus orbiculatusextract(COE) on gastric precancerous lesions(GPL) and to explore its role in the Notch-1 signaling pathway. Methods : GPL rat models were established using a composite model replication method, and the rats were randomly divided into a control group, a model group, and COE low, medium and high dose groups [COE at 12.5, 25, and 50 mg/(kg·d)]. After 4 weeks of intervention, gastric tissue was collected, and immunohistochemistry(IHC) was performed to detect the expression of mucins(MUC2, MUC5AC, and MUC6), Leucine-rich repeat-containing G-protein coupled receptor 5(Lgr5), Proliferating Cell Nuclear Antigen(Ki67), and Notch-1. Polymerase chain reaction(PCR) was used to determine the mRNA levels of the aforementioned mucins. Human gastric epithelial cells(GES-1) were induced with N-Methyl-N′-nitro-N-nitrosoguanidine(MNNG) to establish a GPL cell model. The cells were randomly divided into control, model, and COE low, medium, and high concentration groups(COE at 5, 10, and 20 μg/ml). After 24 hours of corresponding interventions, changes in cell morphology were observed under an inverted microscope. Western blot was used to measure the expression of Notch-1 and Lgr5, and immunofluorescence(IF) was employed to detect Notch-1 expression. Results : Compared to the control group, the expression of MUC2, Lgr5, Notch-1, and Ki67 in the gastric tissue of the model group rats significantly increased(P<0.000 1), while the expression of MUC5AC and MUC6 decreased(P<0.000 1). In comparison to the model group, the expressions of MUC2, Lgr5, Notch-1, and Ki67 were significantly reduced in the COE groups(P<0.01), while the expression of MUC5AC and MUC6 significantly increased(P<0.01). In the GES-1 model group, the cells exhibited irregular morphology, loose intercellular connections, and disorganized arrangement compared to the control group. In contrast, the cells in the COE groups displayed a more regular morphology and a more organized arrangement than those in the model group. Additionally, compared to the control group, the expression of Lgr5 and Notch-1 in the model group were significantly elevated(P<0.000 1), whereas after COE treatment, their expressions were markedly reduced(P<0.001). Conclusion COE can alleviate GPL, and its mechanism may be associated with the downregulation of the Notch-1 signaling pathway, which improves gastric mucosal mucin barrier function and inhibits the abnormal proliferation of gastric mucosal stem cells.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoietic stem cell disease caused by abnormal expression of glycosylphosphatidylinositol (GPI) on the cell membrane due to mutations in the phosphatidylinositol glycan class A(PIGA) gene. It is commonly characterized by intravascular hemolysis, repeated thrombosis, and bone marrow failure, as well as multiple systemic involvement symptoms such as renal dysfunction, pulmonary hypertension, swallowing difficulties, chest pain, abdominal pain, and erectile dysfunction. Due to the rarity of PNH and its strong heterogeneity in clinical manifestations, multidisciplinary collaboration is often required for diagnosis and treatment. Peking Union Medical College Hospital, relying on the rare disease diagnosis and treatment platform, has invited multidisciplinary clinical experts to form a unified opinion on the diagnosis and treatment of PNH, and formulated the Expert Consensus of Multidisciplinary Diagnosis and Treatment for Paroxysmal Nocturnal Hemoglobinuria (2024), with the hope of promoting the standardization of PNH diagnosis and treatment.

Objective To analyze the sequence of LysinB protein in bacteriophage TM4,express LysinB protein in E.coli and evaluate its bactericidal activity in vitro.Methods Bacteriophage TM4 LysinB gene was synthesized and the recombinant prokaryotic expression plasmid was constructed.The soluble protein was induced and purified.The biological characteristics of bacteriophage TM4 LysinB protein were analyzed by online software program.Mycobacterium smegmatis was cultured in 7H9 medium,and its bactericidal effect and stability were detected.Results The theoretical isoelectric point was 6.66,the instability index was 28.71,which was a stable and amphiphilic protein.In the secondary structure,The random coil,α-helix,β-fold and turn Angle accounted for 42.00％,40.25％,12.00％and 5.75％;In the tertiary structure,the content of random coil was high.The peptide composed of AA at positions 11 to 73 constituted the peptidoglycan binding domain.The regions of B cell epitopes and the strong binding peptides of T cell epitopes were predicted.LysinB protein has a significant ability to kill Mycobacterium smegmatis in vitro.PBST protein buffer with pH8.0 was beneficial to maintain the bactericidal effect of LysinB proteins during the experimental cycle.Conclusion This study expands the comprehensive understanding of the LysinB protein of mycobacterial phage TM4 lyase,and also provides reference for the development of stable storage of phage enzyme preparation and its clinical application.

AIM:To investigate the effects of exercise preconditioning(EP)combined with electroacupunc-ture(EA)on learning and memory ability of rats with vascular dementia(VD),and to explore role of hippocampal ferrop-tosis in this process.METHODS:Seventy-two male SD rats were randomly divided into non-EP group and EP group,with 36 rats in each group.The rats were subjected to EP,and subsequently to establish the VD model.The rats from non-EP group were randomly divided into sham group,model group(VD group)and VD-EA group,each with 12 rats,while those in EP group were randomly divided into EP-sham group,EP-VD group and EP-VD-EA group,each with 12 rats.All rats in EP group underwent 4 weeks of swimming exercise training,5 d per week,30 min per day.At the end of the 4th week,the rats in VD,EP-VD,EP-VD-EA and VD-EA groups were used to induce the VD model,and the rats in sham and EP-sham groups received a sham surgery to simulate the VD model.On the 7th day after successful modeling,the rats in EP-VD-EA and VD-EA groups were treated with EA for 4 weeks,6 d per week,30 min per day.At the end of the inter-vention,the learning and memory ability of the rats was evaluated using Morris water maze.Neuron morphology in the CA1 area of rat hippocampus was observed through Nissl staining.Ferrous ion(Fe2+),malondialdehyde(MDA)and re-duced glutathione(GSH)contents in the rat hippocampal tissues were quantified using the colorimetric assay.The expres-sion levels of ferroptosis-related proteins,nuclear factor E2-related factor 2(Nrf2)and glutathione peroxidase 4(GPX4),in the hippocampal tissues were quantified by Western blot method.RESULTS:Compared with sham group,the rats in VD group exhibited longer mean evasion latency and decreased number of traversals across the plateau(P<0.01).The neurons in the CA1 region of the hippocampus were loose and disorganized,exhibiting an irregular cellular morphology.The hippocampal Fe2+and MDA content was elevated,and the GSH content was reduced(P<0.01).The protein levels of hippocampal Nrf2 and GPX4 were decreased(P<0.01).Compared with VD group,the rats in EP-VD,EP-VD-EA and VD-EA groups showed a shorter average escape latency and an increased number of traversals across the plateau(P<0.05).Neurons in the hippocampal CA1 area were more neatly arranged,showing regular cellular morphology.The hip-pocampal Fe2+and MDA contents of the rats in EP-VD group were significantly reduced(P<0.01),while the GSH content was elevated(P<0.05).Hippocampal Fe2+and MDA contents were significantly reduced and GSH contents were signifi-cantly increased in EP-EA and EA groups(P<0.01).The protein levels of hippocampal Nrf2 and GPX4 in EP-VD,EP-VD-EA and VD-EA groups were significantly increased(P<0.01).CONCLUSION:Exercise preconditioning combined with EA improves learning and memory ability in VD rats by reducing hippocampal intra-neuronal iron overload,maintain-ing organismal redox homeostasis,and inhibiting ferroptosis.

This study was performed to investigate the effects of Arbutin(Ar)on oxidative stress,apoptosis level and inflammatory response of H9c2 cardiomyocytes induced by lipopolysaccharide(LPS).H9c2 cardiomyocytes were randomly divided into blank control group,lipopolysaccharide group(LPS),LPS+Ar(25 μmol/L)group,LPS+Ar(50 μmol/L)group,LPS+Ar(100 μmol/L)group and Ar(50 μmol/L)group.CCK-8 was used to detect the cell viability of H9c2 cardiomyocytes after LPS treatment and Ar treatment;DCFH-DA fluorescence labeling was used to detect the ROS levels of H9c2 cardiomyocytes;flow cytometry was applied to detect cell apoptosis rate;Western blot was used to detect the expression of apoptosis-related proteins(Caspase-3)and inflammatory proteins(IL-1β and TNF-α).Data showed that compared with the LPS group,the cell viabilities were recovered after Ar treatment.The level of oxidative stress markers(ROS),apoptosis rate,and inflammatory factor levels(IL-1β and TNF-α)in the LPS+Ar groups were significantly reduced compared with the LPS group(P<0.05).In conclusion,Ar can alleviate the damage,apoptosis,oxidative stress and inflammatory response of LPS-induced H9c2 cardiomyocytes.

Objective Apply modified bilateral carotid artery ligation to establish a VD rat model to observe changes in cerebral blood flow and expression of angiogenic proteins.Methods Thirty-six SD male rats were randomly divided into a sham group(n = 18)and model group(n = 18).In the sham group,only the bilateral carotid artery was isolated without ligation,whereas in the model group,the bilateral carotid artery was ligated to establish the VD model.The Morris water maze behavior test was applied before and 14 days after modeling.Variation in cerebral blood flow was detected by laser speckle contrast imaging.Protein expression of HIF-1α,VEGF,and HO-1 was detected by Western Blot.IL-4 and IL-10 contents were measured by ELISA.Results At 14 days after modeling,escape latency was significantly prolonged and the frequency of crossing the platform had significantly decreased in the model group compared with the sham group(P<0.05).At 2 hours,3 days,and 7 days after modeling,cerebral blood flow in the model group was significantly lower than that in the sham group(P<0.05).At 14 and 21 days after modeling,no significant difference was found in cerebral blood flow between sham and model groups(P>0.05).In the model group,cerebral blood flow was decreased to a minimum at 2 hours after modeling(P<0.05)and then began to recover.The peak of recovery occurred at 3～7 days after modeling and returned to the level before modeling on day 14 after modeling.At postoperative day 21,expression of HIF-1α,VEGF,and HO-1 proteins in the hippocampus of the model group was increased remarkably(P<0.05)and the serum contents of IL-4 and IL-10 in the model group were significantly increased compared with those in the sham group(P<0.05).Conclusions The variation in cerebral blood flow in the VD rat model established by the modified bilateral carotid artery ligation was dependent on time.At postoperative day 21,HIF-1α,VEGF,and HO-1 in the hippocampus were increased significantly,which was accompanied by increased levels of IL-4 and IL-10.

Objective:To explore the application effect of case-based learning (CBL) combined with problem-based learning (PBL) teaching model in refresher training of medical imaging technologists.Methods:The study recruited 46 imaging technologists trained in radiology department in the Batch 2017 and Batch 2018 of West China Hospital of Sichuan University. They were divided into 2 groups: experimental group (23 persons) and control group (23 persons). CBL combined with PBL teaching method was used in the experimental group, and traditional lecture-based learning (LBL) method was used in the control group. The results of attitude evaluation, staged exminations, graduation assessment and operational skill tests were compared between the two groups, and the questionnaire survey was performed to test the affirmation of self-worth of the two groups of interns. SPSS 17.0 was used for chi-square test, independent t test, and Mann-Whitney U test. Results:Theoretical examination results at the second stage, the third stage, completion and operational examination results in the experimental group were significantly higher than those in the control group [(91.17±2.59) vs. (85.26±3.03), (92.00±1.86) vs. (87.43±3.23), (92.39±2.08) vs. (87.04±2.93), (85.70±5.48) vs. (80.87±5.57), P<0.05]. The questionnaire survey showed that such 7 aspects as the stimulation of subject interest, the cultivation of exploration spirit, the exercise of self-learning ability, the establishment of clinical ideas, the analysis of difficult problems, the mastering of practical operations, and the affirmation of self-worth in the experimental group were better than those in the control group, with significant difference ( P<0.05), while the consolidation of theoretical knowledge of the experimental group was not statistically different from the control group ( P>0.05). Conclusion:The reasonable application of CBL combined with PBL teaching model in refresher training of medical imaging technologists is helpful to improve their learning enthusiasm, self-learning ability, clinical analysis ability, practical operation ability, and long-term consolidation of theoretical knowledge.

Objective:To explore the application effect of magnetic resonance imaging (MRI) sequence experiment based on virtual simulation software in undergraduate teaching of medical imaging technology.Methods:Fifty-six undergraduate students from the Batch 2015 and Batch 2016 medical imaging technology of West China Clinical Medical College of Sichuan University were recruited in this study. They were divided into 2 groups: experimental group (Batch 2016) and control group (Batch 2015). The experimental group adopted the teaching method based on virtual simulation experiment, and the control group used the teaching method based on traditional small-sized magnetic resonance. The after-class test scores and final exam scores of the two groups of students were compared, and the questionnaire survey on teaching effectiveness was conducted for students in the experimental group SPSS 21.0 was used for ttest and Mann-Whitney Utest. Results:The scores of theoretical knowledge and the final grades in the experimental group were significantly higher than those of the control group [(84.55 ± 6.57) points vs. (79.37 ± 6.13) points; (90.03 ± 4.72) points vs. (80.06 ± 7.29) points, all P< 0.05). The effective recovery rate of the questionnaires was 100%, and the questionnaire survey showed that the experimental group was significantly superior to the control group in such four aspects as increasing subject interest, expanding relevant knowledge, solving clinical work, and promoting teamwork ( P< 0.05). Conclusion:In MRI sequence teaching, the teaching method based on virtual simulation software can increase the students' interests in learning, strengthen their understanding of MRI principles, then effectively improve the teaching effect of medical imaging undergraduate education.

Objective:To explore the application effect of case-based learning combined with problem-based learning teaching model in refresher training of medical imaging technologists.Methods:The study recruited 46 imaging technologists trained in radiology department in the Batch 2017 and Batch 2018 of West China Hospital of Sichuan University. They were divided into 2 groups: experimental group (23 persons) and control group (23 persons). Case-based learning combined with problem-based learning teaching method was used in the experimental group, and traditional lecture-based learning method was used in the control group. 2 test was used for sex distribution comparisons between the two groups, and independent t test was conducted to compare the differences in age, working years, entrance examination results, attitude rating scores, stage examination scores, completion examination scores, and operational examination scores between the two groups. Mann-Whitney U test was used for comparisons of non-parametric variables between the two groups, such as qualifications, occupation title, and questionnaire results.Results:Theoretical examination results at the second stage, the third stage, completion and operational examination results in the experimental group were higher than those in the control group [(91.17±2.59) vs. (85.26±3.03), (92.00±1.86) vs. (87.43±3.23), (92.39±2.08) vs. (87.04±2.93), (85.70±5.48) vs. (80.87±5.57), P<0.05]. The questionnaire survey showed that the stimulation of subject interest, the cultivation of exploration spirit, the exercise of self-learning ability, the establishment of clinical ideas, the analysis of difficult problems, the mastering of practical operations, and the affirmation of self-worth in the experimental group were better than those in the control group, with significant difference [4(3, 4) scores vs. 3(2, 3) scores, 4(3, 4) scores vs. 2(2, 3) scores, 3(3, 4) scores vs. 2(2, 3) scores, 3(3, 4) scores vs. 3(2, 3) scores, 3(3, 4) scores vs. 2(2, 3) scores, 4(3, 4) scores vs. 3(2, 3) scores, 4(3, 4) scores vs. 3(2, 3) scores, P<0.05], while the consolidation of theoretical knowledge of the experimental group was not different from the control group [3(2, 3) scores vs. 3(2, 3) scores, P>0.05]. Conclusions:The reasonable application of case-based learning combined with problem-based learning teaching model in refresher training of medical imaging technologists is helpful to improve their learning enthusiasm, self-learning ability, clinical analysis ability, practical operation ability, and long-term consolidation of theoretical knowledge, and it also can contribute to affirmation of self-worth.