Objective To design an experimental device for simulating the interface micro motion of bone trabecular prosthesis and carry out the finite element analysis.Methods The experimental device was composed of a screw-in cylinder with threads,a flexible hinge,a micro-motion rod,a trabecular prosthesis,a connecting rod and a fixation post.A model of the experimental device was constructed with SolidWorks software,and then imported into ABAQUS software to establish a finite element model.An axial displacement load was applied to the femur to analyze the effects of the position of the flexible hinge,the gap between the prosthesis and the femur and the length of the connecting rod on the micro motion.Results The interface micro motion produced by the experimental device increased with the distance of the flexible hinge from the lower end of the screwed-in cylinder;the gap between the prosthesis and the femur did not affect the interface micro motion when the gap was not lower than 20 μm;the interface micro motion rose with the length of the connecting rod.Conclusion The experimental device can accurately simulate the micro motion of different bone trabecular prosthesis interfaces,and can be used for studying the effect of the interface micro motion on osseointegration.[Chinese Medical Equipment Journal,2024,45(1):25-30]

Objective To explore the regulatory mechanism of Macelignan on oxidative stress-mediated neuronal injury in autophagy and apoptosis.Methods Murine hippocampal neuronal HT22 cells were treated with 2.5 mmol·L-1 glutamic acid(Glu)to establish an oxidative stress cell model.The cells were divided into normal group(normal cultured cells),model group(2.5 mmol·L-1 Glu)and experimental-L,-M,-H groups(2.5,5,10 μmol·L-1Macelignan treatment),inhibitor group(2.5 mmol·L-1 Glu+10 μmol·L-1 Macelignan+10 μmol·L-1 LY294002).Aoptosis rate was detected by flow cytometry;the protein expression level of autophagy-related protein LC3B(LC3B),anti-SQSTM1/p62(p62),p21,B-cell lymphoma-2(Bcl-2)and Bcl-2 associated X protein(Bax)was detected by Western blot.Results The apoptosis rates in the normal group,model group and experimental-L,-M,-H groups were(4.58±1.25)％,(8.75±0.55)％,(6.30±1.71)％,(5.97±2.27)％and(5.49±1.71)％.The difference between model group and normal group was statistically significant(P＜0.01).The difference between experimental-L,-M,-H groups and model group was statistically significant(all P＜0.01).The levels of LC3B in normal group,model group,experimental-L,experimental-M,experimental-H groups and inhibitor group were 0.28±0.02,0.74±0.02,1.02±0.04,0.70±0.03,0.26±0.02 and 0.21±0.01;p62 levels were 0.49±0.08,0.33±0.03,0.50±0.07,0.59±0.01,0.64±0.13 and 0.65±0.06;p21 levels were 0.87±0.02,1.18±0.03,0.98±0.03,0.88±0.03,0.72±0.06 and 0.81±0.02;Bcl-2/Bax levels were 1.74±0.23,1.11±0.10,1.38±0.05,1.66±0.26,1.58±0.29 and 1.53±0.09,respectively.The differences between model group and normal group,between model group and experimental-H group,between model group and inhibitor group,were also statistically significant(all P＜0.01).Conclusion Macelignan can reduce the damage of hippocampal neurons induced by glutamate acid by regulating the process of autophagy and apoptosis,and has obvious neuroprotective effect.

In recent years,natural antimicrobial peptides have become an important direction in the development of novel antibiotics.Cecropin has the characteristics of wide antibacterial spectrum,good tolerance and low adverse drug reactions.As the first antimicrobial peptide discovered in the family of Cecropin,Cecropin A has many important biological activities.In this paper,the research on the antibacterial,antifungal,antiparasitic and antitumor activities of Cecropin A and its derivatives in recent years was reviewed,and its application prospect was prospected,in order to provide reference for further research and development of cecropin.

Objective Studies on the relationship between iodine,vitamin A(VA),and vitamin D(VD)and thyroid function are limited.This study aimed to analyze iodine and thyroid-stimulating hormone(TSH)status and their possible relationships with VA,VD,and other factors in postpartum women. Methods A total of 1,311 mothers(896 lactating and 415 non-lactating)from Hebei,Zhejiang,and Guangxi provinces were included in this study.The urinary iodine concentration(UIC),TSH,VA,and VD were measured. Results The median UIC of total and lactating participants were 142.00 μg/L and 139.95 μg/L,respectively.The median TSH,VA,and VD levels in all the participants were 1.89 mIU/L,0.44 μg/mL,and 24.04 ng/mL,respectively.No differences in the UIC were found between lactating and non-lactating mothers.UIC and TSH levels were significantly different among the three provinces.The rural UIC was higher than the urban UIC.Obese mothers had a higher UIC and a higher prevalence of excessive TSH.Higher UICs and TSHs levels were observed in both the VD deficiency and insufficiency groups than in the VD-sufficient group.After adjustment,no linear correlation was observed between UIC and VA/VD.No interaction was found between vitamins A/D and UIC on TSH levels. Conclusion The mothers in the present study had no iodine deficiency.Region,area type,BMI,and VD may be related to the iodine status or TSH levels.

Objective To understand the pathogen detection of hospitalized patients before antimicrobial therapy in a hospital through implementation of comprehensive intervention measures,and provide reference basis for the de-velopment of targeted measures.Methods Hospitalized patients who received therapeutic antimicrobial agents in this hospital were selected as the research subjects.Patients who were hospitalized from January to May 2022 were selected as the pre-intervention group,comprehensive intervention measures were taken from June to October 2022,and those who were hospitalized from November 2022 to March 2023 were selected as the post-intervention group.The pathogen detection rate before antimicrobial therapy,sterile specimen detection rate,antimicrobial use rate,de-tection rate of key multidrug-resistant organisms of patients before and after the intervention were analyzed.Results Compared to before intervention,the proportion of pathogen detection rate before antimicrobial therapy(62.09％vs 74.04％),detection rate of healthcare-associated infection diagnosis-related pathogens(62.82％vs 92.73％),and sterile specimen detection rate(35.17％vs 41.06％)of hospitalized patients after intervention all increased signifi-cantly,with statistically significant differences(all P＜0.05).After intervention,pathogen detection rate before the combination use of key antimicrobial agents was not statistically different from before intervention(93.33％vs 90.48％,P＞0.05),while antimicrobial use rate was lower than before intervention(39.93％vs 44.95％,P＜0.05).There was no statistically significant difference in the detection rate of key multidrug-resistant organisms be-fore and after intervention(all P＞0.05).Conclusion Adopting scientific and rational intervention measures can improve the pathogen detection rate,provide a reference basis for the rational use of antimicrobial agents.There was no significant improvement in the pathogen detection rate before the combination use of key antimicrobial agents and the detection rate of key multidrug-resistant organisms,indicating that relevant measures still need to be further optimized.

Objective To analyze the stresses in implanted titanium solid and bone trabecular prosthesis hip replacements.Methods A femur model was built inversely based on Mimics software,and optimized using Geomagic software,and then materialized by SolidWorks software.The osteotomized femur was assembled with the metal femoral stem to form a model,and then the model was imported into ABAQUS for finite element calculation.The upper femur was divided into four regions in different states of integration:medial proximal point(small trochanter region),lateral proximal region(large trochanter region),proximal point of the femoral stem(region around the mid-portion of the styloid process)and distal region(around the end of the styloid process and distal portion).Calculations were carried out over the femoral stresses before and after implantation of titanium solid and trabecular prostheses under gait and stair-climbing loads and the interfacial stresses when the region was unintegrated.The type of deformation at the bone interface was analyzed by means of a stress ellipsoid.Results At the small trochanter region,the stress shielding rates of the trabecular prosthesis under gait and stair climbing loads were reduced by 20.5％and 14.7％compared to the titanium solid prosthesis,respectively.In case of different integration states of the titanium solid prosthesis,the interface tensile stresses under the gait and stair climbing loads were up to 10.842 MPa and 12.900 MPa,and the shear stresses reached 7.050 MPa and 6.805 MPa,respectively;in case of different integration states of the trabecular prosthesis,the interface tensile stresses under the gait and stair climbing loads were up to 3.858 MPa and 4.389 MPa,and the shear stresses reached 4.156 MPa and 3.854 MPa,respectively.Under the 2 different loads,the inboard shear stress ellipsoid of the interface opened toward the sides and the bone interface showed tensile deformation;the outboard shear stress ellipsoid of the interface opened up and down and had compressive deformation.Conclusion After total hip arthroplasty,the overall performance of the trabecular prosthesis is better than that of the titanium solid prosthesis.The unintegrated edges of the prosthesis-bone interface are susceptible to stress concentrations and distortion which may result in occurrence of failures.[Chinese Medical Equipment Journal,2024,45(3):29-35]

Objective To explore the mechanical behavior of cancellous bone under the interaction of whole-body low-magnitude high-frequency vibration(LMHFV)parameters,in order to provide theoretical guidance for the clinical treatment of disuse osteoporosis.Methods A three-dimensional reconstruction model was established for the cancellous bone of the mid femur by Mimics software,which was then imported into Comsol software to form a three-dimensional fluid-solid coupling finite element model.Twelve scenarios with the vibration acceleration amplitude(a)being 0.015×g,0.02×g,0.03×g and vibration frequency(f)being 30,45,60 and 100 Hz were set up for the simulation study to analyze the distribution rules of the hydrodynamic microenvironment,the stresses and the deformation displacements of cancellous bone under the interaction of LMHFV parameters.Results The bone marrow flow velocity on the surface of trabeculae and deformation displacement of bone matrix increased with the rising of a and decreased with the growing of f.Trabeculae gained high mean values of deformation displacement in case of the vibration scenario(0.015×g/0.02×g/0.03×g,30 Hz),and had high von Mises stress when LMHFV parameters were restricted within(0.02×g to 0.03×g,30 Hz to 35 Hz).Conclusion Whole-body LMHFV significantly improves the force and hydrodynamic environment of cancellous bone,and force-mediated osteoblast bioactivity can be enhanced by rationally modulating LMHFV parameters during clinical processes so as to promote osteogenesis.[Chinese Medical Equipment Journal,2024,45(7):17-23]

RNA fluorescence aptamers are RNA sequences that can specifically bind to non-toxic,cell permeable,and self-fluorescent target molecules and activate their luminescent properties.These aptamers provide powerful tools for biosensing and imaging researches due to their simple structure,easy synthesis,and easy transfection.This article summarized the characteristics and development history of various RNA fluorescent aptamers,including Malachite Green,Spinach,Broccoli,Mango,Corn,and Pepper family,as well as their corresponding fluorescent groups.The applications of RNA fluorescent aptamers were also reviewed from two aspects:extracellular detection and cell imaging.This review might provide guidance for labeling,detection and interactions of molecules from proof of concept and clinical assessment to practical clinical and biomedical applications.

Aim To study the active ingredients and mechanism of action of Xinkeshu tablets against myo-cardial ischemia by network pharmacology and ze-brafish model.Methods The anti-myocardial ische-mia activity of Xinkeshu tablets was evaluated by iso-prenaline hydrochloride(ISO)-induced zebrafish myo-cardial ischemia model and H2O2-induced H9c2 dam-age model.The active ingredients of Xinkeshu tablets were retrieved using databases such as TCMSP.The potential targets were predicted by PharmaMapper data-base.Myocardial ischemic disease targets were searched by OMIM database.The potential therapeutic targets of Xinkeshu tablets against myocardial ischemia were analyzed.GO and KEGG enrichment analysis were conducted on core targets.The active ingredients were verified by zebrafish and cell model.qRT-PCR was used to detect the expression of key targets.Re-sults Xinkeshu tablets could significantly alleviate ISO-induced pericardial edema and bradycardia.It al-so could increase sinus venous-bulb aortic(SV-BA)distance and improve the cell viability.The 30 poten-tial active ingredients of Xinkeshu tables mainly acted on 30 core targets,including ALB,AKT1 and MAPK1,to regulate 627 GO items,including protein phosphorylation,negative regulation of apoptosis and positive regulation of PI3K signal transduction.KEGG results showed that 117 signaling pathways,including PI3K/Akt,FOXO and Ras,exerted anti-myocardial ischemia effect.Salvianolic acid A,lithospermic acid,rosmarinic acid,salvianolic acid D,salvianolic acid B,ginsenoside Rg2,hyperoside,3'-methoxypuerarin,3'-hydroxypuerarin and ginsenoside Rg1 could alleviate ISO-induced zebrafish myocardial ischemia and im-prove the cell viability.Xinkeshu tablets could upregu-late the expression of genes such as ras and akt1,and downregulate the expression of genes such as mapk1 and mapk8.Conclusion The active ingredients,in-cluding salvianolic acid A in Xinkeshu tablets,exert anti-myocardial ischemia effects by targeting targets,such as AKT1,MAPK1,and regulating signaling path-ways,such as PI3K/Akt,MAPK and Ras.

Objective:To evaluate early residual myocardial ischemia after successful percutaneous coronary intervention (PCI) in patients with coronary artery disease by using myocardial perfusion imaging (MPI) and investigate independent influencing factors of early residual myocardial ischemia.Methods:From January 2020 to December 2022, 127 patients (107 males, 20 females; age (60.3±9.6) years) with coronary artery disease who underwent PCI complete revascularization at the First People′s Hospital of Changzhou were consecutively enrolled prospectively. All patients underwent rest and stress MPI within 1-3 months after PCI. Reversible myocardial perfusion defect in the blood supply area of the culprit vessels in stress and rest MPI was defined as early residual myocardial ischemia after PCI. Accordingly, the culprit vessels undergoing PCI were divided into residual ischemic group and non-ischemic group. Differences of cardiovascular examination between two groups were compared ( χ2 test), such as proportion of culprit vessels with severe stenosis (≥90%), proportion of bifurcation lesions, and proportion of diffuse coronary disease. Logistic regression analyses were performed to identify influencing factors for early residual myocardial ischemia. Results:Among 148 culprit vessels undergoing PCI in 127 patients, early residual myocardial ischemia was present in 49 vessels (33.1%, 49/148). The proportion of culprit vessels with severe stenosis before PCI in residual ischemia group was higher than that in non-ischemia group (69.4%(34/49) and 49.5%(49/99); χ2=5.27, P=0.022). The proportion of bifurcation lesions in residual ischemic group was also higher than that in non-ischemic group (28.6%(14/49) and 10.1%(10/99); χ2=8.23, P=0.004), with a slightly higher proportion of diffuse coronary disease compared to non-ischemic group (14.3%(7/49) and 4.0%(4/99); χ2=3.62, P=0.057). Multivariate logistic regression analysis showed that bifurcation lesion (odds ratio ( OR)=4.087, 95% CI: 1.615-10.344, P=0.003) and diffuse coronary disease ( OR=4.208, 95% CI: 1.115-15.878, P=0.034) were independent influencing factors for early residual myocardial ischemia. Conclusions:Early residual myocardial ischemia is still present in about 1/3 of the culprit vessels after PCI complete revascularization. Bifurcation lesion and diffuse coronary disease are independent influencing factors for early residual myocardial ischemia in culprit vessels.