Flagella are important protein structures on the cell surface of bacteria and the main appendage for bacterial swimming. Flagella play a crucial role in bacterial motility, chemotaxis, pathogenicity, and environmental sensing. With the development of microscopic tracking technology and flagellum visualization tools, new forms of flagellar motility and increasing roles of flagella in the physiological activities of bacteria have been discovered. This review introduces the visualization methods of flagella and the applications of these methods in studying flagellar functions, giving insights into exploring the functions of flagella and laying a theoretical foundation for its future applications in inhibiting bacterial transmission and treating bacterial infections.
Flagella/physiology* ; Bacterial Physiological Phenomena ; Chemotaxis/physiology* ; Bacteria

Objective To investigate the nutritional quality characteristics of vitamin D3-fortified yogurt and explore its improving effect on vitamin D metabolism in the body under simulated weightlessness,thereby providing a theoretical basis for the development of functional foods.Methods Using reconstituted milk as the matrix and Vitamin D3(VD3)microcapsule powder as the fortifier,VD3-fortified yogurt was prepared.A systematic study was conducted to investigate the effects of different gradients(1.25 μg/100 mL,2.50 μg/100 mL,3.75 μg/100 mL,5.00 μg/100 mL,6.25 μg/100 mL)of VD3 microcapsule addition on its quality characteristics(titratable acidity,solid content,water-holding capacity,syneresis).In vivo assessments were conducted using a Sprague-Dawley(SD)rat tail-suspension model to simulate weightlessness.Levels in serum 25(OH)D3,1,25-(OH)2D3,calcium(Ca),and phosphorus(P)were detected using the enzyme-linked immunosorbent assay(ELISA)to evaluate its metabolic capacity.Results During fermentation(3 h),titratable acidity of VD?-fortified yogurt initially increased,then decreased,and eventually stabilized with rising microcapsule dosage,while total solid content remained consistent.WHC exhibited an initial increase followed by a decline,whereas syneresis showed an inverse trend.At an optimal dosage of 3.75 μg/100 mL,the yogurt displayed a dense and uniform network structure,characterized by non-Newtonian fluid behavior with shear-thinning properties.This formulation demonstrated robust structural stability under high-frequency mechanical stress,alongside desirable textural,flavor,and sensory attributes.Animal experiments revealed that the serum concentrations of 25(OH)D3,1,25-(OH)2D3,calcium,and phosphorus in the vitamin D?-fortified yogurt intervention group were significantly higher than those in the tail-suspended control group(P<0.05).Conclusion VD? microencapsulation technology effectively preserves and enhances the nutritional quality characteristics of yogurt and mitigates vitamin D metabolic dysregulation under simulated weightlessness.

Pyruvate kinase M2(PKM2)is closely linked to a variety of neurological disorders,involved in the onset and progression of a wide range of diseases,including Alzheimer's disease,Parkinson's disease,multiple sclerosis and traumatic brain injury through such mechanisms as aerobic glycolysis,oxidative stress,inflammation and apoptosis.This review is intended to provide an overview of the biological characteristics of PKM2 and its role in the pathophysiological mechanisms of neurological disorders.A better understanding of the correlations between PKM2 and the development of neurological diseases can offer new insights into and references for the clinical diagnosis and treatment of these conditions.

Objective To explore the effect of physical exercise on semen quality in order to provide basic data and theoretical basis for the improvement of male reproductive health.Methods A cross-sectional study was conducted on 1 059 males who visited the Reproductive Medicine Center of Shandong Maternal and Child Health Hospital for medical treatment and physical examination during July 2022 and April 2023.Their demographic data and physical exercise data were surveyed with questionnaires.Total sperm count,sperm concentration,total sperm motility,forward movement and normal sperm morphology were analyzed with computer aided analysis.Logistic regression model and multiple linear regression model were applied to analyze the effects of physical exercise on semen quality.Results After adjustment for confounding factors such as age,body mass index,alcohol consumption and smoking,logistic regression analysis showed that the risk of abnormal semen quality was increased in patients with moderate and heavy exercise intensity(OR=2.103,OR=2.229).Compared with the participants with physical exercise ≤10 min per session,those with＞20 min per session had a lower risk of abnormal semen quality(OR=0.357,0.256,0.289 for exercise time for＞20～30,＞30～60,＞60 min,respectively).There was no statistical significance between physical exercise frequency and semen quality(P＞0.05).The participants having exercise well were at a lower risk for abnormal semen quality(OR=0.711).Multiple linear regression analysis revealed that the frequency of physical exercise was an influencing factor of sperm concentration(β=7.474,95％CI:4.800～10.149,P＜0.05);the time of physical exercise per session was an influencing factor for total sperm count(β=20.632,95％CI:7.634～33.629);the intensity of physical exercise(β=-1.461,95％CI:-2.392～-0.530)and time of physical exercise per session(β=2.608,95％CI:1.404～3.812,P＜0.05)were influencing factors for percentage of forward motility sperm(P＜0.05);and physical exercise intensity(β=-1.934,95％CI:-3.238～-0.630),time of physical exercise per session(β=4.211,95％CI:2.525～5.897)and frequency of physical exercise(β=-2.008,95％CI:-3.480～-0.536)were influencing factors of total sperm motility(P＜0.05).Conclusion Physical exercise may affect semen quality,greater intensity of physical exercise may be a risk factor for abnormal semen quality,and longer physical exercise time may be related to improving semen quality.Therefore,proper physical exercise can help improve semen quality.

Cartilage is solid connective tissue that recovers slowly from injury, and pain and dysfunction from cartilage damage affect many people. The treatment of cartilage injury is clinically challenging and there is no optimal solution, which is a hot research topic at present. With the rapid development of 3D printing technology in recent years, 3D bioprinting can better mimic the complex microstructure of cartilage tissue and thus enabling the anatomy and functional regeneration of damaged cartilage. This article reviews the methods of 3D printing used to mimic cartilage structures, the selection of cells and biological factors, and the development of bioinks and advances in scaffold structures, with an emphasis on how 3D printing structure provides bioactive cargos in each stage to enhance the effect. Finally, clinical applications and future development of simulated cartilage printing are introduced, which are expected to provide new insights into this field and guide other researchers who are engaged in cartilage repair.

Cartilage is solid connective tissue that recovers slowly from injury,and pain and dysfunction from cartilage damage affect many people.The treatment of cartilage injury is clinically challenging and there is no optimal solution,which is a hot research topic at present.With the rapid development of 3D printing technology in recent years,3D bioprinting can better mimic the complex microstructure of cartilage tissue and thus enabling the anatomy and functional regeneration of damaged cartilage.This article reviews the methods of 3D printing used to mimic cartilage structures,the selection of cells and biological factors,and the development of bioinks and advances in scaffold structures,with an emphasis on how 3D printing structure provides bioactive cargos in each stage to enhance the effect.Finally,clinical applications and future development of simulated cartilage printing are introduced,which are expected to provide new insights into this field and guide other researchers who are engaged in cartilage repair.

OBJECTIVE: To investigate the incidence and potential risk factors associated with postoperative spinal epidural hematoma (SEH) following anterior cervical spine surgery (ACSS). METHODS: A retrospective analysis was conducted on the clinical data of patients who underwent ACSS for cervical spondylosis at Peking University Third Hospital between March 2013 and February 2022. Patients who developed postoperative SEH were categorized as the SEH group, while those in the cohort without SEH were randomly selected as the non-SEH group by individually matching with the same operator, same gender, same surgery year, and similar age (±5 years) at a ratio of 4 ∶ 1. The general condition, preoperative comorbidities, anticoagulant or antiplatelet therapy, preoperative coagulation and platelet counts, American society of Anesthesiologists physical status classification, cervical spondylosis classification, preoperative modified Japanese Orthopaedic Society score and cervical disability index score, surgical modality, surgical segment levels, ossification of the posterior longitudinal ligament among the surgical level, surgery duration, estimated blood loss, postoperative drainage volume, preoperative mean arterial pressure, mean arterial pressure during postoperative awakening periods, hospital stay and hospitalization cost were compared between the two groups. A bivariate Logistic regression model was applied to screen out the independent risk factors and calculate the odds ratios of indicators associated with SEH. Receiver operating characteristic curve and area under the curve (AUC) were used to describe the discrimination ability of the indicators. RESULTS: A total of 85 patients were enrolled in the study, including 17 patients in the SEH group and 68 patients in the non-SEH group. Seventeen patients with SEH underwent hematoma evacuation, and all of them were successfully treated and discharged from the hospital. Corpectomy (OR=7.247; 95%CI: 1.962-26.766; P=0.003) and the highest mean arterial pressure during awakening (OR=1.056; 95%CI: 1.002-1.113; P=0.043) were independent risk factors for SEH. The AUC values were 0.713 (95%CI: 0.578-0.848) and 0.665 (95%CI: 0.51-0.82) respectively. The patients with SEH had longer hospital stays (P < 0.001) and greater hospitalization costs (P=0.035). CONCLUSION Corpectomy and elevated maximum mean arterial pressure during awakening are independent risk factors for the development of postoperative SEH following ACSS. High-risk patients should be closely monitored during the perioperative period.
Humans ; Risk Factors ; Cervical Vertebrae/surgery* ; Retrospective Studies ; Hematoma, Epidural, Spinal/epidemiology* ; Incidence ; Male ; Female ; Postoperative Complications/etiology* ; Spondylosis/surgery* ; Logistic Models ; Length of Stay ; Middle Aged

Sepsis is a complex syndrome caused by multiple pathogens and involves multiple organ failure, particularly spleen dysfunction. In 2017, the worldwide incidence was 48.9 million sepsis cases and 11 million sepsis-related deaths were reported (Rudd et al., 2020). Inflammation, oxidative stress, and apoptosis are the most common pathologies seen in sepsis. Liensinine (LIE) is a bisbenzylisoquinoline-type alkaloid extracted from the seed embryo of Nelumbo nucifera. Lotus seed hearts have high content of LIE which mainly has antihypertensive and antiarrhythmic pharmacological effects. It can exert anti-carcinogenic activity by regulating cell, inflammation, and apoptosis signaling pathways (Manogaran et al., 2019). However, its protective effect from sepsis-induced spleen damage is unknown. In this research, we established a mouse sepsis model induced by lipopolysaccharide (LPS) and investigated the protective effects of LIE on sepsis spleen injury in terms of inflammatory response, oxidative stress, and apoptosis.
Mice ; Animals ; Lipopolysaccharides/pharmacology* ; Spleen ; Inflammation ; Apoptosis ; Sepsis ; Oxidative Stress

Objective:To collect data on urinary flow rate in the elderly female population across the country and to analyze the range of reference values.Methods:This study enrolled 333 subjects from July 2020 to June 2022.The study implementation process was divided into two steps.In the first step, subjects completed an electronic questionnaire, which included basic information about the subject, a short form for urinary incontinence, and a scoring form for the symptoms of overactive bladder syndrome.In the second step, the staff introduced the use of a mobile uroflowmetric device and distributed the instrument and materials.Uroflow rate data were automatically uploaded to a cloud database via the mobile phone.Subsequently, two or more physicians specializing in urinary control performed Uroflow rate-qualifying screenings and conducted statistical analyses.Results:A total of 333 subjects were enrolled in the study, and the researchers collected 1375 qualified urine flow rate records using a mobile urine flow rate instrument.The age of the subjects ranged from 60 to 84 years, with a mean age of 69 years.The reference ranges for urinary flow rate were found to be 24.8-26.2 s, with a mean urinary flow rate of 12.2-12.9 ml/s, a maximum urinary flow rate of 22.2-23.4 ml/s, and a time to peak of 8.5-9.7 s. The study observed a tendency for both maximal and mean urinary flow rates to decrease in older women as their age increased(Pearson correlation coefficient: -0.1, P<0.001). Conclusions:The uroflow rate of older women decreases with aging.Specifically, the average uroflow rate of women over 80 years old is lower than that of other age groups.This study aims to establish normal uroflow parameters for uroflowmetry in healthy older women in China.

Objective: To observe the effects of electroacupuncture (EA) pretreatment on M1 polarization of alveolar macrophages (AMs) in rats with acute lung injury (ALI) induced by lipopolysaccharide (LPS), and to explore the potential protective mechanism of EA.Methods: Forty Sprague-Dawley rats were randomly divided into a normal group, a model group, and three groups of EA pretreatment [including a Chize (LU5) group, a Zusanli (ST36) group and a Chize (LU5) plus Zusanli (ST36) group], with eight rats in each group. The model rats of ALI were established by instilling LPS [2 mg/(kg·bw)] into the trachea of rats for 3 h. The rats in each EA pretreatment group were pretreated with EA for 30 min per day at the corresponding bilateral acupoints 6 d before instilling LPS. Three hours after modeling, the pulmonary function of the rats was tested, and the lung tissue was taken to calculate the ratio of lung wet weight to dry weight (W/D). The pathological lung changes and the injury score were observed by hematoxylin-eosin staining. The contents of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and myeloperoxidase (MPO) in rat's bronchoalveolar lavage fluid (BALF) were detected by enzyme-linked immunosorbent assay. The mRNA and protein expression levels of M1 macrophage markers clusters of differentiation 86 (CD86), inducible nitric oxide synthase (iNOS), and its signaling pathway factor Toll-like receptor (TLR) 4, and nuclear factor-κB (NF-κB) p65 in the alveoli were detected by fluorescence quantitative polymerase chain reaction and Western blot, respectively. Results: After being induced by LPS, the pulmonary function of the model rats showed that the forced expiratory volume in 0.1 s (FEV0.1), forced expiratory volume in 0.3 s (FEV0.3), and their respective ratios of FEV to forced vital capacity (FVC) (including FEV0.1/FVC and FEV0.3/FVC) were significantly decreased (P<0.01), while the W/D of lung tissue was increased (P<0.01). The score of lung injury was significantly higher (P<0.01). The contents of TNF-α, IL-1β, and MPO in the BALF and the mRNA and protein expression levels of CD86, iNOS, TLR4, and NF-κB p65 in the lung tissue were significantly increased (P<0.01). After EA pretreatment, the FEV0.1, FEV0.3, FEV0.1/FVC, and FEV0.3/FVC were significantly increased, the lung injury score decreased significantly, and the contents of TNF-α, IL-1β, and MPO in the BALF and the expression levels of CD86, iNOS, TLR4, and NF-κB p65 mRNAs and proteins in the alveoli decreased significantly (P<0.05 or P<0.01). Compared with the other two single acupoint groups, the contents of TNF-α, IL-1β, and MPO in the BALF and the expression levels of CD86, iNOS, TLR4, and NF-κB p65 mRNAs in the alveoli in the Chize (LU5) plus Zusanli (ST36) group were significantly lower (P<0.01). Conclusion: EA pretreatment at Chize (LU5) and Zusanli (ST36) can inhibit inflammation and reduce pulmonary injury in ALI rats induced by LPS. The effect of the combination of Chize (LU5) and Zusanli (ST36) is better than that of using these two acupoints separately, and its mechanism may be related to the inhibition of AMs' M1 polarization by down-regulation TLR4/NF-κB signaling pathway.