OBJECTIVE: To evaluate the effect of biodegradable magnesium alloy materials in promoting tendon-bone healing during rotator cuff tear repair and to investigate their potential underlying biological mechanisms. METHODS: Forty-eight 8-week-old Sprague Dawley rats were taken and randomly divided into groups A, B, and C. Rotator cuff tear models were created and repaired using magnesium alloy sutures in group A and Vicryl Plus 4-0 absorbable sutures in group B, while only subcutaneous incisions and sutures were performed in group C. Organ samples of groups A and B were taken for HE staining at 1 and 2 weeks after operation to evaluate the safety of magnesium alloy, and specimens from the supraspinatus tendon and proximal humerus were harvested at 2, 4, 8, and 12 weeks after operation. The specimens were observed macroscopically at 4 and 12 weeks after operation. Biomechanical tests were performed at 4, 8, and 12 weeks to test the ultimate load and stiffness of the healing sites in groups A and B. At 2, 4, and 12 weeks, the specimens were subjected to the following tests: Micro-CT to evaluate the formation of bone tunnels in groups A and B, HE staining and Masson staining to observe the regeneration of fibrocartilage at the tendon-bone interface after decalcification and sectioning, and Goldner trichrome staining to evaluate the calcification. Immunohistochemical staining was performed to detect the expressions of angiogenic factors, including vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2), as well as osteogenic factors at the tendon-bone interface. Additionally, immunofluorescence staining was used to examine the expressions of Arginase 1 and Integrin beta-2 to assess M1 and M2 macrophage polarization at the tendon-bone interface. The role of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway in tendon-bone healing was further analyzed using real-time fluorescence quantitative PCR. RESULTS: Analysis of visceral sections revealed that magnesium ions released during the degradation of magnesium alloys did not cause significant toxic effects on organs such as the heart, liver, spleen, lungs, and kidneys, indicating good biosafety. Histological analysis further demonstrated that fibrocartilage regeneration at the tendon-bone interface in group A occurred earlier, and the amount of fibrocartilage was significantly greater compared to group B, suggesting a positive effect of magnesium alloy material on tendon-bone interface repair. Additionally, Micro-CT analysis results revealed that bone tunnel formation occurred more rapidly in group A compared to group B, further supporting the beneficial effect of magnesium alloy on bone healing. Biomechanical testing showed that the ultimate load in group A was consistently higher than in group B, and the stiffness of group A was also greater than that of group B at 4 weeks, indicating stronger tissue-carrying capacity following tendon-bone interface repair and highlighting the potential of magnesium alloy in enhancing tendon-bone healing. Immunohistochemical staining results indicated that the expressions of VEGF and BMP-2 were significantly upregulated during the early stages of healing, suggesting that magnesium alloy effectively promoted angiogenesis and bone formation, thereby accelerating the tendon-bone healing process. Immunofluorescence staining further revealed that magnesium ions exerted significant anti-inflammatory effects by regulating macrophage polarization, promoting their shift toward the M2 phenotype. Real-time fluorescence quantitative PCR results demonstrated that magnesium ions could facilitate tendon-bone healing by modulating the PI3K/AKT signaling pathway. CONCLUSION Biodegradable magnesium alloy material accelerated fibrocartilage regeneration and calcification at the tendon-bone interface in rat rotator cuff tear repair by regulating the PI3K/AKT signaling pathway, thereby significantly enhancing tendon-bone healing.
Animals ; Rotator Cuff Injuries/metabolism* ; Rats, Sprague-Dawley ; Signal Transduction ; Wound Healing/drug effects* ; Alloys/pharmacology* ; Rats ; Proto-Oncogene Proteins c-akt/metabolism* ; Rotator Cuff/metabolism* ; Macrophages/metabolism* ; Magnesium/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Male ; Biocompatible Materials ; Bone Morphogenetic Protein 2/metabolism*

One of the technical bottlenecks limiting the high yield of 1,4-butanediamine is the insufficient tolerance of strains to 1,4-butanediamine. Enhancing the tolerance of strains to 1,4-butanediamine is therefore a primary challenge that needs to be addressed for the construction of strains with high yields of 1,4-butanediamine. Staphylococcus pasteuri 326180 exhibits exceptional tolerance to high-concentration 1,4-butanediamine, serving as both an ideal model for studying the mechanism underlying the 1,4-butanediamine tolerance and a novel host for constructing strains capable of efficiently producing 1,4-butanediamine. However, for both the research on the tolerance mechanism and the modification of chassis strains, gene editing of S. pasteuri needs to be carried out at the molecular level. The research objective of this paper is to establish a genetic manipulation system for S. pasteuri, laying foundation for subsequent studies on tolerance mechanism and the modification of chassis strains. This study systematically optimized the electroporation conditions, including key parameters such as the growth phase of cells, electric field strength, electroporation buffer, and recovery medium, successfully establishing an electroporation method for S. pasteuri. Additionally, we constructed the gene editing plasmid pCpfOA by replacing the resistance expression cassette, optimized the selection markers for gene editing, and finally established a CRISPR/Cpf1-based gene editing technology for S. pasteuri, achieving an editing efficiency of 90%. The genetic manipulation system of S. pasteuri established in this study provides technical support for research into the tolerance mechanism of this bacterium and the genetic modification of chassis strains.
Staphylococcus/drug effects* ; Gene Editing/methods* ; Electroporation/methods* ; Plasmids/genetics* ; CRISPR-Cas Systems ; Genetic Engineering/methods*

Objective To develop a high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for simultaneous determination of five flavonoids in Ganmao'an granules(GMA).Methods Chromatographic separation was achieved on a Kromasil C18 Column(150 mm×4.6 mm,5 μm,100 ?),which was eluted with methanol(A)-0.1％formic acid(B)at the flow rate of 1.0 ml/min.The gradient condition was as follows:0-20 min,35％A,and 20-40 min,45％A.The column temperature was 25 ℃.Analytes were detected using a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization source in the negative ion scanning.The multiple reaction monitoring mode was used for qualitative analysis.For each flavonoid,two precursor ion/product ion transitions were chosen:lutin m/z 609.1→300.1,hyperin and isoquercitrin m/z 463.0→300.1,quercetin m/z 301.0→151.0,luteolin m/z 285.0→132.9.Results Five flavonoids showed the good relationships within their own concentration ranges(correlation coefficient r>0.999 1),whose average recoveries were in the range of 100.63％-102.81％with RSDs of 0.67％-2.07％.The content results of rutin,hyperoside,isoquercetin,quercetin,and luteolin in 10 batches of GMA were 32.23-479.83,0.291-1.825,11.44-20.54,6.32-18.41,3.46-6.51 μg/g,respectively.Conclusion The results indicated that the developed method was sensitive,accurate and could provide excellent specificity for simultaneous determination of five flavonoids in GMA.

The disease risk prediction model is the basis of precision prevention and an essential reference for clinical treatment decisions. The development of risk prediction models requires the support of a large amount of high-quality data. A large population cohort study is an important basis for this study. The United Kingdom Biobank (UKB), as a mega-population cohort and biobank, has played an essential role in the exploration of disease etiology and research related to disease prevention and control, with its rich baseline and follow-up data and concepts and mechanisms shared globally. This study followed PRISMA guidelines and included 210 articles with corresponding authors from 18 countries, of which 58 (27.62%) were from the UKB. A total of 491 disease risk prediction models were extracted for cancer, cardiovascular and cerebrovascular diseases, endocrine and metabolic diseases, respiratory diseases, and other diseases and their subgroups, of which 132 were developed by UKB without validation, 183 were developed by UKB with internal validation, 17 were developed by UKB with external validation, and 159 were developed by external development with UKB validation. A total of 188 models used only macro variables (38.29%), and 303 models combined macro and micro variables (61.71%). Model construction methods included survival outcome models, logistic regression, and machine learning. Survival outcome models were dominated by Cox proportional risk regression models and a few models considering competitive risk, accelerated failure models, or different baseline risk functions. Machine learning models included random forest, XGBoost, CatBoost, support vector machine, convolutional neural network, and other methods. The UKB is an essential resource for multiple disease risk prediction modeling studies.

Objective:Based on the specific cleavage and non-specific "trans-cleavage" activities of the clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein(CRISPR/Cas13), we established a visually amplification-free rapid detection technique of 2019-nCoV nucleic acid. This technique is easily processed with a low detection limit and good specificity.Methods:According to the 2019-nCoV gene sequence, specific CRISPR RNAs were screened and designed by bioinformatics analysis, and then synthesized as universal signal-strained RNA transcription targets in vitro to establish and optimize the reaction system. Moreover, the 2019-nCoV pseudoviral nucleic acid was used as a standard substance to evaluate the detection limit. A total of 65 positive samples were collected from various 2019-nCoV variants, while 48 negative samples included other clinically common respiratory pathogens, such as influenza A virus, influenza B virus, human parainfluenza virus, Klebsiella pneumonia, etc. All samples were tested by quantitative PCR (qPCR), digital PCR, and the method established in this study. The sensitivity and specificity of the newly established method were analyzed and evaluated. Results:With the newly established technique, the detection time for 2019-nCoV nucleic acid could be minimized to 6 minutes. In addition, the detection limit was 14 copies/μl when assisted by the displaying instrument, whereas it increased to 28 copies/μl with the naked eye. This technique had a sensitivity and specificity of 98.5% (66/67) and 100% (46/46) respectively, showing no statistically significant difference compared to the gold standard qPCR( P=1). Conclusions:This study has successfully established a CRISPR/Cas13a-based visually rapid detection technique for 2019-nCoV nucleic acid. This technique offers the advantages of a simple process, convenient operation, low environmental operating requirements, a detection limit close to qPCR, and a strong potential for on-site testing applications.

Pseudorabies virus(PRV)is the etiological agent of pseudorabies in pigs,which is char-acterized by dyspnea,reproductive disorders,and neurological diseases,and it spreads widely a-round the world.Since 2011,the newly emerged PRV variants have resulted in poor immunity pro-tection of traditional vaccine strains,and the original method of vaccine strain preparation is time-consuming and labor-intensive.Therefore,it is urgently needed to develop an efficient screening method of the vaccine strain at present.Using CRISPR/Cas9 gene editing technology in this study,two single guide RNAs(sgRNA)were designed targeting the virulence gene TK of PRV variant strain CH/JX/2016,and then the enhanced green fluorescent protein the reporter(EGFP)gene was inserted at the TK locus by a homologous repair plasmid.After multiple rounds of plaque puri-fication,the rPRV-ΔTK/EGFP strain was obtained.The results showed the cleavage efficiency of the two sgRNAs was extremely high.The preparation of rPRV-ΔTK/EGFP strain was succeed af-ter only three rounds of purification,and the EGFP expressed normally.The CRISPR/Cas9 system can edit the PRV gene simply,rapidly,and efficiently,and exhibits great potential in the construction of vaccine candidate strains.Meanwhile,the rescued rPRV-ΔTK/EGFP strain not only could be used as a tracer strain in PRV variant infection progresses,but also for subsequent antivi-ral drug screening.

The aim of this experiment is to investigate the mechanism of liver cell damage induced by nonylphenol(NP).After establishing an in vitro model of NP induced BRL-3A liver cell injury,changes of oxidative damage markers were evaluated,Fe2+content was determined,the ultrastruc-ture of BRL-3A was observed,and the expression level of iron death marker proteins were deter-mined.The results showed that NP could significantly increase ROS and MDA in BRL-3A cells(P＜0.05);the GSH content,GSH Px activity,and SOD activity were significantly reduced(P＜0.05);the Fe2+content significantly increased(P＜0.05)and showed a dose-dependent effect;the mitochondrial volume of BRL-3A cells significantly decreases,the mitochondrial cristae break or e-ven disappear,and some mitochondria show vacuolization;the expression levels of iron homeostasis related proteins TFR1 and FTH1 were significantly reduced(P＜0.05).The results indicate that ferroptosis is involved in the mechanism of NP induced liver cell damage,which bene-fits for further exploration of NP pathogenesis.

Objective To investigate the role and potential mechanisms of tumor necrosis factor alpha-inducible protein 8-like molecule 1(TNFAIP8L1)in acute liver injury in mice.Methods The second generation of C57BL/6J male wild-type(WT)mice and the C57BL/6J female TNFAIP8L1+/-mice and WT mice were selected to further self-breed the third generation of male TNFAIP8L1-/-mice and the third generation of WT male mice.Five normal third-generation male WT mice and five normal third-generation male TNFAIP8L1-/-mice were selected.The serum alanine aminotransferase(ALT)levels of the two types of normal mice were measured and compared.The infiltration of inflammatory cells and cell necrosis in the liver tissues of the two types of normal mice were observed after hematoxylin & eosin(HE)staining.Flow cytometry was used to detect the percentages of neutrophils(Neu),eosinophils(EOS),dendritic cells(DC),bone marrow-derived macrophages(BMDMs),and bone marrow-derived mononuclear cell(BMNCs)in the liver myeloid cell subsets of the two types of normal mice.Another 5 third-generation male WT mice and 4 third-generation male TNFAIP8L1-/-mice were selected to induce acute liver injury mouse models using lipopolysaccharide(LPS)/D-galactosamine(D-Gal).After 24 hours,the serum ALT levels of the two types of acute liver injury mice were detected and compared,the infiltration of inflammatory cells and cell necrosis in the liver tissues of the two types of acute liver injury mice were observed,and the percentages of Neu,EOS,DC,BMDMs and BMNCs in the liver myeloid cell subsets of the two types of acute liver injury mice were measured by using the above methods.Results There was no significant difference in the percentages of Neu,EOS,DC,BMDMs and BMNCs,and serum ALT levels in the livermyeloid cell subsets of normal WT mice and TNFAIP8L1-/-mice(P＞0.05).HE staining results of liver tissues in normal WT mice and TNFAIP8L1/mice showed that hepatic lobules were structurally complete and clear,hepatocytes were morphologically normal and arranged neatly,and there was no obvious inflammatory cell infiltration or cell necrosis.Twenty-four hours after acute liver injury,the percentages of Neu and BMNCs in the liver myeloid cell subsets and the serum ALT levels in the liver tissues of TNFAIP8L1-/-mice were significantly higher than those of WT mice(P＜0.05);there was no significant difference in the percentages of EOS,DC and BMDMs in the liver myeloid cell subsets of mice between the two groups(P＞0.05).In the liver tissues of WT mice with acute liver injury,hepatic lobules were structurally blurred,hepatocytes were swollen with scattered vacuolated steatosis,and a small amount of inflammatory cells were infiltrated.In the liver tissues of TNFAIP8L1/mice with acute liver injury,hepatic lobules were structurally non-existent,and hepatocytes were severely damaged and extensively necrotic,with a large amount of inflammatory cell infiltration.Conclusion The deficiency of the TNFAIP8L1 gene in mice does not affect the development of liver myeloid cells and the homeostasis of the liver.TNFAIP8L1 plays an inhibitory role in the occurrence and development of acute liver injury.TNFAIP8L1 gene deficiency aggravates LPS/D-Gal-induced acute liver injury,possibly by increasing Neu and BMNCs infiltration and recruiting other types of immune cells to infiltrate liver tissues,thereby exacerbating liver cell necrosis.

Objective To establish a novel real-time quality control method for rapidly identifying the random error of sodium ion con-centration in serum using an artificial intelligence voting algorithm,and evaluate the relevant effectiveness of the model established on this basis.Methods A total of 144 754 test results of serum sodium ion rom the inpatients measured by Beckman AU5400 biochemis-try analyzer from January to May 2021 were obtained retrospectively from laboratory information system of the Department of Clinical La-boratory,Nanjing Drum Tower Hospital,and all the data were used as unbiased data for the current study.The random errors were arti-ficially introduced to generate the corresponding biased data set.Subsequently,the voting algorithm-based internal quality control model(ViQC)was established using the principles of the voting algorithm.The ViQC model and five classical PBRTQC(patient-based real-time quality control)algorithms were performed direct to each biased data.The analytical performance of the ViQC model was evaluated by using classification model criteria.The trimmed average number of patient samples until error detection(tANPed)was used to com-pare the clinical detection efficacy of the ViQC model with those of the five classical algorithms,and the error detection curves were plotted.Results Compare with all the classical algorithms,the ViQC model showed a false positive rate below 0.002 and achieved ac-curacy above 0.951 in detecting all the deviations.When the error factors were 1.5,2.5,and 3.0,the false positive rate of the ViQC model was zero.When the error factor was 2.5,its accuracy reached 0.979.Compared to the five classical PBRTQC algorithms,the ViQC model reduced the overall average tANPed by up to 34％and showed higher sensitivity for error detection.In addition,the ViQC model demonstrated the area under the ROC curve was as high as 0.989 at TEa on the test set,but the value of tANPed wasonly five.Conclusion We successfully established a real-time quality control model for the data of patients based on artificial intelligence algo-rithms,and its efficacy of clinical detection was superior to the traditional PBRTQC algorithms.

Objective To analyze the relationship between serum microRNA(miR)-204 and miR-200b lev-els and clinical efficacy in patients with oral submucosal fibrosis(OSF).Methods A total of 110 patients with OSF who visited Affiliated Hospital of Hebei Engineering University from December 2021 to December 2022 were collected as the study group,another 50 healthy people who underwent physical examination during the same period were collected as the control group.The quantitative real-time PCR(qRT-PCR)method was ap-plied to detect and compare the serum levels of miR-204 and miR-200b in the study group and the control group.The study group was divided into miR-204 high expression group and low expression group,and miR-200b high expression group and low expression group.The clinical efficacy,transforming growth factor β1(TGF-β1),interleukin-6(IL-6),clinical pathological features,and visual analogue scale(VAS)of patients with different levels of serum miR-204 and miR-200b were compared,and Spearman and Pearson methods were applied to analyze the correlation between serum miR-204 and miR-200b levels and various indicators in the study group.Results The serum level of miR-204 and miR-200b in the study group was obviously lower than those in the control group,and the difference was statistically significant(P＜0.05).The total effective rates of patients in the high expression group of miR-204 and the high expression group of miR-200b were both 100.00％,which were higher than the total effective rates of the low expression group of miR-204 and the low expression group of miR-200b(86.79％and 88.89％)respectively,and the differences were statisti-cally significant(P＜0.05).The results of univariate analysis showed that the serum levels of miR-204 and miR-200b in OSF patients with chewing betel nut,mouth opening degree≤28 mm,oral mucosal lesion area＞4 cm2,and VAS score＞3 points were obviously lower than those with non chewing betel nut,mouth opening degree＞28 mm,oral mucosal lesion area≤4 cm2,and VAS score≤3 points,and the differences were statis-tically significant(P＜0.05).The levels of TGF-β1 and IL-6 in patients with high expression of miR-204 and miR-200b were obviously lower than those in patients with low expression of miR-204 and miR-200b,and the differences were statistically significant(P＜0.05).The correlation analysis results showed that the serum levels of miR-204 and miR-200b in patients with OSF were negatively correlated with oral mucosal lesion are-a,VAS score,TGF-β1,IL-6(P＜0.05),and positively correlated with mouth opening degree(P＜0.05).Conclusion The serum levels of miR-204 and miR-200b in patients with OSF are closely related to clinical ef-ficacy,and when the serum levels of miR-204 and miR-200b increase,OSF patients have better clinical efficacy.