Metastasis is the leading cause of death from cutaneous melanoma. Identifying metastasis-related targets and developing corresponding therapeutic strategies are major areas of focus. While functional genomics strategies provide powerful tools for target discovery, investigations at the protein level can directly decode the bioactive epitopes on functional proteins. Aptamers present a promising avenue as they can explore membrane proteomes and have the potential to interfere with cell function. Herein, we developed a target and epitope discovery platform, termed functional aptamer evolution-enabled target identification (FAETI), by integrating affinity aptamer acquisition with phenotype screening and target protein identification. Utilizing the aptamer XH3C, which was screened for its migration-inhibitory function, we identified the Chondroitin Sulfate Proteoglycan 4 (CSPG4), as a potential target involved in melanoma migration. Further evidence demonstrated that XH3C induces cytoskeletal rearrangement by blocking the interaction between the bioactive epitope of CSPG4 and integrin α4. Taken together, our study demonstrates the robustness of aptamer-based molecular tools for target and epitope discovery. Additionally, XH3C is an affinity and functional molecule that selectively binds to a unique epitope on CSPG4, enabling the development of innovative therapeutic strategies.

Objective:To evaluate the effect of baicalein on acute myocardial injury in rats with high-level spinal cord injury (SCI) and the role of nuclear factor E2-related factor 2 (Nrf2).Methods:Twenty-four clean-grade healthy male Sprague-Dawley rats, aged 8-10 weeks, weighing 250-300 g, were divided into 4 groups ( n=6 each) using a random number table method: sham operation group (Sham group), SCI group, SCI+ baicalein group (SCI+ Bai group) and SCI+ baicalein+ ML385 group (SCI+ Bai+ ML385 group). The high-level SCI rat model was established by the modified Allens method. In Sham group, the 7th cervical vertebra (C 7) was only exposed, but the spinal cord was not hit. In SCI group, C 7 was exposed and the spinal cord was hit. In SCI+ Bai group, baicalein 50 mg/kg was intraperitoneally injected immediately after SCI. In SCI+ Bai+ ML385 group, Nrf2 inhibitor ML385 30 mg/kg was intraperitoneally injected at 1 h before SCI, and baicalein 50 mg/kg was intraperitoneally injected immediately after SCI. The rats were anesthetized at 24 h after SCI and sacrificed after the blood samples from the abdominal aorta were collected and the hearts were taken for microscopic examination of the pathological changes (by HE staining) which were scored and the ultrastructure of cells (with a transmission electron microscope) and for determination of the serum cardiac troponin I (cTnI) concentrations (by enzyme-linked immunosorbent assay), content of ferrous ion (Fe 2+ ) in myocardial tissues (by colorimetry), contents of malondialdehyde(MDA) and glutathione (GSH) and activity of superoxide dismutase(SOD) in myocardial tissues (by biochemical method) and expression of glutathione peroxidase 4 (GPX4), acyl CoA synthase long chain family member 4 (ACSl4) and Nrf2 protein and mRNA in myocardial tissues (by Western blot and fluorescent quantitative polymerase chain reaction). The mitochondrial Flameng score was assessed and recorded. Results:Compared with Sham group, the pathological score, mitochondrial Flameng score and serum cTnI concentrations were significantly increased, the contents of Fe 2+ and MDA in myocardial tissues were increased, the content of GSH and SOD activity were decreased, the expression of GPX4 was down-regulated, and the expression of ACSL4 and Nrf2 was up-regulated in SCI group ( P<0.05). Compared with SCI group, the pathological score, mitochondrial Flameng score and serum cTnI concentration were significantly decreased, the contents of Fe 2+ and MDA in myocardial tissues were decreased, the contents of GSH and SOD activity were increased, the expression of GPX4 and Nrf2 was up-regulated, and the expression of ACSL4 was down-regulated in SCI+ Bai group ( P<0.05). Compared with SCI+ Bai group, the pathological score, mitochondrial Flameng score and serum cTnI concentrations were significantly increased, the contents of Fe 2+ and MDA in myocardial tissues were increased, the content of GSH and SOD activity were decreased, the expression of GPX4 and Nrf2 was down-regulated, and the expression of ACSL4 was up-regulated in SCI+ Bai+ ML385 group ( P<0.05). Conclusions:Baicalein can alleviate acute myocardial injury in rats with high-level SCI, and Nrf2 is involved in this process.

Objective:To investigate the therapeutic efficacy and disruptive effects of Meropenem（MEM）-loaded microbubbles（MBs）combined with ultrasound targeted microbubble destruction（UTMD）technology on Escherichia coli and its biofilm.Methods:MEM-MBs were prepared using the thin-film hydration method，and their characterization was assessed using a Zeta potential analyzer，with morphological observations conducted under an optical microscope. An in vitro biofilm model of periprosthetic joint infection（PJI）caused by Escherichia coli was constructed，and the morphology of the biofilm and the distribution of MEM-MBs in the bacterial biofilm were observed under a laser confocal microscope after staining the biofilm with SYTO59 staining and DIL staining for Microbubbles. The biofilm morphology and the distribution of MEM-MBs in bacterial biofilm were observed under laser confocal microscope. The biofilms were randomly divided into 5 groups using a random number table：control，Meropenem（MEM），MEM-MBs，UTMD，and MEM-MBs+UTMD，with 12 samples per group. After applying the respective interventions，scanning electron microscopy（SEM）and laser scanning confocal microscopy（LSCM）were employed to observe the effects on the morphology and structure of Escherichia coli and its biofilm. Crystal violet staining was utilized to determine and compare the biofilm density among groups using a microplate reader. LSCM was also used to observe the biofilm thickness，while both LSCM and spread plate counting were employed to assess bacterial viability differences across groups.Results:①MEM-MBs meeting the experimental requirements were successfully constructed.②A dense Escherichia coli biofilm visible under both the naked eye and LSCM was established，with a thickness of（10.61 ± 0.17）μm and a proportion of dead bacteria within the biofilm of（16.8 ± 0.8）%.③MEM-MBs were observed to penetrate into all layers of the biofilm using LSCM.④The results of crystal violet staining showed a decreasing trend in the biofilm density of the control group，the MEM group，the MEM-MBs group，the UTMD group，and the MEM-MBs+UTMD group. There was no significant difference between the MEM group and the MEM-MBs group（ P＞0.05），while there was a significant difference in biofilm density between the other groups，as revealed by pairwise comparison（all P＜0.05）.⑤UTMD technique and MEM-MBs+UTMD could significantly disrupt the biofilm of Escherichia coli. LSCM results showed that，compared to the control group，the thickness of the biofilm was reduced in all other groups，with only the UTMD group and the MEM-MBs+UTMD group showing an increase in porosity（both P＜0.05）. In comparison with the MEM group and the MEM-MBs group，the UTMD group showed an increase in porosity，while the MEM-MBs+UTMD group had a decrease in biofilm thickness and an increase in porosity（both P＜0.05）. Additionally，compared to the UTMD group，the MEM-MBs+UTMD group had a decrease in biofilm thickness and an increase in porosity（both P＜0.05），based on laser confocal microscopy results.⑥The results of the plate counting and LSCM showed that，compared with the control group，clump counts decreased，and the proportion of dead cells increased in the MEM group，the MEM-MBs group，and the MEM-MBs+UTMD group（all P＜0.05）. Compared with MEM group and MEM-MBs group，the clump counts of UTMD group increased，the proportion of dead cells decreased（all P＜0.05）；the clump counts of MEM-MBs+UTMD group decreased，and the proportion of dead cells increased（all P＜0.05）.Compared with UTMD group（all P＜0.05），the clump counts of MEM-MBs+UTMD group decreased，while the proportion of dead cells increased（all P＜0.05）.⑦The results of scanning electron microscopy revealed that the network structure of Escherichia coli was completely destroyed in the MEM-MBs+UTMD group. Conclusions:UTMD technology combined with MEM-MBs exerts a significant disruptive effect on the morphology and structure of Escherichia coli biofilm and significantly enhances bactericidal efficacy.

Objective:To evaluate the effect of baicalein on acute myocardial injury in rats with high-level spinal cord injury (SCI) and the role of nuclear factor E2-related factor 2 (Nrf2).Methods:Twenty-four clean-grade healthy male Sprague-Dawley rats, aged 8-10 weeks, weighing 250-300 g, were divided into 4 groups ( n=6 each) using a random number table method: sham operation group (Sham group), SCI group, SCI+ baicalein group (SCI+ Bai group) and SCI+ baicalein+ ML385 group (SCI+ Bai+ ML385 group). The high-level SCI rat model was established by the modified Allens method. In Sham group, the 7th cervical vertebra (C 7) was only exposed, but the spinal cord was not hit. In SCI group, C 7 was exposed and the spinal cord was hit. In SCI+ Bai group, baicalein 50 mg/kg was intraperitoneally injected immediately after SCI. In SCI+ Bai+ ML385 group, Nrf2 inhibitor ML385 30 mg/kg was intraperitoneally injected at 1 h before SCI, and baicalein 50 mg/kg was intraperitoneally injected immediately after SCI. The rats were anesthetized at 24 h after SCI and sacrificed after the blood samples from the abdominal aorta were collected and the hearts were taken for microscopic examination of the pathological changes (by HE staining) which were scored and the ultrastructure of cells (with a transmission electron microscope) and for determination of the serum cardiac troponin I (cTnI) concentrations (by enzyme-linked immunosorbent assay), content of ferrous ion (Fe 2+ ) in myocardial tissues (by colorimetry), contents of malondialdehyde(MDA) and glutathione (GSH) and activity of superoxide dismutase(SOD) in myocardial tissues (by biochemical method) and expression of glutathione peroxidase 4 (GPX4), acyl CoA synthase long chain family member 4 (ACSl4) and Nrf2 protein and mRNA in myocardial tissues (by Western blot and fluorescent quantitative polymerase chain reaction). The mitochondrial Flameng score was assessed and recorded. Results:Compared with Sham group, the pathological score, mitochondrial Flameng score and serum cTnI concentrations were significantly increased, the contents of Fe 2+ and MDA in myocardial tissues were increased, the content of GSH and SOD activity were decreased, the expression of GPX4 was down-regulated, and the expression of ACSL4 and Nrf2 was up-regulated in SCI group ( P<0.05). Compared with SCI group, the pathological score, mitochondrial Flameng score and serum cTnI concentration were significantly decreased, the contents of Fe 2+ and MDA in myocardial tissues were decreased, the contents of GSH and SOD activity were increased, the expression of GPX4 and Nrf2 was up-regulated, and the expression of ACSL4 was down-regulated in SCI+ Bai group ( P<0.05). Compared with SCI+ Bai group, the pathological score, mitochondrial Flameng score and serum cTnI concentrations were significantly increased, the contents of Fe 2+ and MDA in myocardial tissues were increased, the content of GSH and SOD activity were decreased, the expression of GPX4 and Nrf2 was down-regulated, and the expression of ACSL4 was up-regulated in SCI+ Bai+ ML385 group ( P<0.05). Conclusions:Baicalein can alleviate acute myocardial injury in rats with high-level SCI, and Nrf2 is involved in this process.

Objective:To investigate the therapeutic efficacy and disruptive effects of Meropenem（MEM）-loaded microbubbles（MBs）combined with ultrasound targeted microbubble destruction（UTMD）technology on Escherichia coli and its biofilm.Methods:MEM-MBs were prepared using the thin-film hydration method，and their characterization was assessed using a Zeta potential analyzer，with morphological observations conducted under an optical microscope. An in vitro biofilm model of periprosthetic joint infection（PJI）caused by Escherichia coli was constructed，and the morphology of the biofilm and the distribution of MEM-MBs in the bacterial biofilm were observed under a laser confocal microscope after staining the biofilm with SYTO59 staining and DIL staining for Microbubbles. The biofilm morphology and the distribution of MEM-MBs in bacterial biofilm were observed under laser confocal microscope. The biofilms were randomly divided into 5 groups using a random number table：control，Meropenem（MEM），MEM-MBs，UTMD，and MEM-MBs+UTMD，with 12 samples per group. After applying the respective interventions，scanning electron microscopy（SEM）and laser scanning confocal microscopy（LSCM）were employed to observe the effects on the morphology and structure of Escherichia coli and its biofilm. Crystal violet staining was utilized to determine and compare the biofilm density among groups using a microplate reader. LSCM was also used to observe the biofilm thickness，while both LSCM and spread plate counting were employed to assess bacterial viability differences across groups.Results:①MEM-MBs meeting the experimental requirements were successfully constructed.②A dense Escherichia coli biofilm visible under both the naked eye and LSCM was established，with a thickness of（10.61 ± 0.17）μm and a proportion of dead bacteria within the biofilm of（16.8 ± 0.8）%.③MEM-MBs were observed to penetrate into all layers of the biofilm using LSCM.④The results of crystal violet staining showed a decreasing trend in the biofilm density of the control group，the MEM group，the MEM-MBs group，the UTMD group，and the MEM-MBs+UTMD group. There was no significant difference between the MEM group and the MEM-MBs group（ P＞0.05），while there was a significant difference in biofilm density between the other groups，as revealed by pairwise comparison（all P＜0.05）.⑤UTMD technique and MEM-MBs+UTMD could significantly disrupt the biofilm of Escherichia coli. LSCM results showed that，compared to the control group，the thickness of the biofilm was reduced in all other groups，with only the UTMD group and the MEM-MBs+UTMD group showing an increase in porosity（both P＜0.05）. In comparison with the MEM group and the MEM-MBs group，the UTMD group showed an increase in porosity，while the MEM-MBs+UTMD group had a decrease in biofilm thickness and an increase in porosity（both P＜0.05）. Additionally，compared to the UTMD group，the MEM-MBs+UTMD group had a decrease in biofilm thickness and an increase in porosity（both P＜0.05），based on laser confocal microscopy results.⑥The results of the plate counting and LSCM showed that，compared with the control group，clump counts decreased，and the proportion of dead cells increased in the MEM group，the MEM-MBs group，and the MEM-MBs+UTMD group（all P＜0.05）. Compared with MEM group and MEM-MBs group，the clump counts of UTMD group increased，the proportion of dead cells decreased（all P＜0.05）；the clump counts of MEM-MBs+UTMD group decreased，and the proportion of dead cells increased（all P＜0.05）.Compared with UTMD group（all P＜0.05），the clump counts of MEM-MBs+UTMD group decreased，while the proportion of dead cells increased（all P＜0.05）.⑦The results of scanning electron microscopy revealed that the network structure of Escherichia coli was completely destroyed in the MEM-MBs+UTMD group. Conclusions:UTMD technology combined with MEM-MBs exerts a significant disruptive effect on the morphology and structure of Escherichia coli biofilm and significantly enhances bactericidal efficacy.

Objective:To analyze the results of the practice test and formal test of the annual professional proficiency test for residents in 2022, to investigate related influencing factors and the effectiveness of the practice test, and to propose the measures for improving the results of the annual professional proficiency test.Methods:The scores of the annual professional proficiency test were analyzed for 202 residents who participated in the test in 2022, and the data on sex, education background, type of personnel, whether they passed the medical licensing examination, and practice test scores were analyzed to investigate related influencing factors. SPSS 23.0 and GraphPad Prism 8 were used for the chi-square test, the t-test, the one-way of variance, and the Fisher's exact test. A multiple linear regression analysis was used to identify influencing factors, and a Pearson correlation analysis was also performed. Results:The scores of the annual professional proficiency test for 202 residents were normally distributed with the highest number of the residents with a score of 90-99 points and the lowest number of the residents with a score of <70 points. The residents who passed the medical licensing examination had a significantly higher score of the annual professional proficiency test than those who failed the examination ( t=2.87, P=0.005), and the residents who passed the three practice tests had a significantly higher score of the annual professional proficiency test than those who failed the practice tests ( P<0.05). The score of the second practice test, the score of the third practice test, and the passing of medical licensing examination were independent influencing factors for the score of annual professional proficiency test ( R2=0.236, R2=0.201, F=6.60, P<0.05). The correlation analysis showed that the scores of the three practice tests were positively correlated with the final score ( r=0.189, 0.373, and 0.311, P<0.05). Conclusions:Improving the passing rate of medical licensing examination and strengthening pre-examination practice tests can help to improve the score of annual professional proficiency test. At the same time, it is necessary to improve the quality of training through the measures such as strengthening the homogenization management of different types of students, improving the attention and enthusiasm of all levels, and accelerating the construction of question banks.

Background Bacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. Objective To understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. Methods Three subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO₂), fine particulate matter (PM_2.5), and inhalable particulate matter (PM₁₀) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min⁻¹, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO₂ concentration and total bacterial count. Results The pass rates were 100.0% for airborne total bacteria count, PM_2.5, and PM₁₀ in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO₂, but 0% for humidity. The overall median (P₂₅, P₇₅) total bacteria count was 177 (138,262) CFU·m⁻³. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. Conclusion The total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas.

Objective:To investigate the expression level of serum microRNA-122-5p (miR-122-5p) in elderly patients with chronic atrophic gastritis (CAG) and its correlation with inflammatory factors and disease severity.Methods:A total of 120 CAG patients admitted to our hospital from Dec. 2019 to Dec. 2021 were selected as as the experimental group. According to the gastric mucosa pathological score, the patients were grouped into 58 cases with normal condition and 62 cases with severe condition. Another 105 patients with chronic non-atrophic gastritis during the same period were included as the control group. The expression level of serum miR-122-5p was detected by qRT-PCR, the level of serum hs-CRP was detected by immunoturbidimetry, the levels of serum TNF-α and IL-6 were detected by enzyme-linked immunosorbent assay (ELISA), and the correlation of serum miR-122-5p expression level with hs-CRP, IL-6, TNF-α and disease severity in CAG patients was analyzed by Pearson method. Logistic regression was used to analyze the risk factors of affecting CAG.Results:There were no significant differences in gender, age, or the proportion of patients with smoking history between the CAG group and the control group ( P>0.05). The proportions of drinking and Hp positive patients in the CAG group were 52.50% and 62.50%, which were significantly higher than those in the control group (25.71%, 43.80%) ( P<0.05) ; The serum levels of miR-122-5p, hs-CRP, IL-6, and TNF-α in the CAG group were (2.31±0.42), (24.89±4.56) mg/L, (39.26±7.68) ng/mL, and (85.42±9.65) pg/ml, respectively, which were significantly higher than the control group [ (1.05±0.12), (16.54±3.85) mg/L, (22.39±5.21) ng/ml, (862.34±7.46) pg/ml] ( P<0.05) ; Serum hs-CRP, IL-6, TNF-αlevels, miR-122-5p expression levels, Hp positive infection rate and pathological score in patients with severe CAG disease were (28.14±3.21) mg/L, (44.55±5.73) ng/ml, (93.42±8.81) pg/ml, 2.74±0.30, 72.58%, (4.30±1.20) points, respectively, which were significantly higher than those of patients with normal disease [ (21.42±3.67) mg/L, (33.61±5.54) ng/ml, (76.87±7.59) pg/mL, 1.85±0.36, 51.72%, (1.60±0.30) points] ( P<0.05) ; correlation analysis showed that serum miR-122-5p expression level in CAG patients was positively correlated with hs-CRP, IL-6, TNF-α and disease severity ( r=0.475, 0.453, 0.505, 0.563, P<0.001). Multivariate logistic analysis showed that Hp positive infection ( OR=2.527, 95% CI=1.125-5.678), miR-122-5p ( OR=2.323, 95% CI=1.341-4.025) were independent risk factors for CAG ( P<0.05) . Conclusion:The expression level of serum miR-122-5p in elderly patients with CAG is increased, which is related to serum inflammatory factors, disease severity and Hp infection, and may be a marker for the diagnosis of CAG.

Objective:To understand the effect of standardized residency training for residents with different identity types, and put forward targeted optimization and improvement measures to achieve the homogenization of training effect.Methods:Combined with literature review and expert consultation results, a self-designed questionnaire was conducted for 324 residents who completed their courses in 2019 and 2020. The effective recovery rate of the questionnaire was 87.65%. By comparing the passing rate of first-time medical admission and completion examination of different identity types, and the training standards of six core competencies, the training effect conclusion was drawn. T-test and Fisher exact probability test were also made by SPSS 21.0. Results:The passing rates of first-time doctors and completion examinations were higher in professional masters and units than in the general population, with the highest passing rates reaching 100% (10/10) and 97.3% (72/74) respectively. There was no statistical difference between the passing rates of residents with different identity types. The overall standard of the six core competencies of the integrated professional masters was better than that of the society and unit personnel. There were statistical differences between the groups in the training standards of the four abilities of the residents with different identity types in professional literacy ( P=0.048), patient management ( P=0.030), communication and cooperation ( P=0.026) and learning promotion ( P=0.003). There was no significant difference in professional ability ( P=0.131) and teaching ability ( P=0.061). Conclusion:There is no difference in the passing rate of residents with different identity types in a military hospital, which achieves the goal of homogenization training to a certain extent. However, there are obvious differences in the standards of the six core competencies, and further optimization measures need to be explored.

Objective:To investigate whether KtrA was a binding protein of c-di-AMP, the second messenger in Leptospira, and to explore the function and regulatory mechanism of the c-di-AMP-KtrA/B system. Methods:KtrA gene was amplified by PCR and cloned into pET42a plasmid to construct the pET42a ktrA prokaryotic expression vector. Then the vector was transferred into E. coli BL21DE3 to construct an engineering bacterium E. coli BL21DE3 pET42a-ktrA for the expression of recombinant KtrA (rKtrA). The expressed rKtrA was purified by affinity chromatography. BIAcore technology was used to detect the binding ability of rKtrA to c-di-AMP. Bacterial two-hybrid analysis was used to analyze the interaction between KtrA and KtrB in the leptospiral Ktr system with or without exogenetic c-di-AMP. The above genes were then complemented into the potassium transport-deficient E. coli mutants to analyze the function of the c-di-AMP-KtrA/B pathway. Results:An prokaryotic engineering bacterium for the expression of ktrA gene of Leptospira was constructed successfully. The purified rKtrA could specifically bind to c-di-AMP. There was interaction between KtrA and KtrB, but the interaction could be dissociated by c-di-AMP. The KtrA/B system was involved in potassium ion uptake and it was negatively regulated by c-di-AMP. Conclusions:Leptospiral KtrA was a c-di-AMP-binding protein and the c-di-AMP-KtrA/B system was involved in potassium ion transport.