Clinically, atrial fibrillation (AF) is one of the most common cardiac arrhythmia, and patients with arterial fibrillation carry high risk of stroke. Oral administration of anticoagulation such as warfarin for the prevention of stroke has some risks to induce bleeding; moreover, some patients are not able to tolerate the medication. Percutaneous occlusion of the left atrial appendage is safe and effective for the prevention of stroke in patients with atrial fibrillation, although at present it is only used for the patients who have contraindications to anticoagulation medication. This paper aims to review a variety of left atrial appendage occlusion devices and to analyze the relationship between the different shape design of occluder and the left atrial appendage morphology.

Objective To explore the method and technique to gain adequate seed cells for cartilage tissue engineering Methods hTERT gene was introduced into rabbit mandibular condylar chondrocytes by eukaryotic vector Rapidly proliferated immortalized chondrocytes in positive clones in micro carrier rotary cell culture system (RCCS) were screened and selected The growth of immortalized chondrocytes and the metabolic rate were observed Collagen type Ⅱ expression of immortalized chondrocytes of the experimental groups was observed The immunohistochemical results were compared with those of the control groups Results The immortalized chondrocytes in experimental groups could grow rapidly with a high metabolic rate and shorter population doubling time (PD) ( P

Objective:To investigate the effects of two SNP sites of delta-like ligand protein-1 (DLL1) gene rs2738822 (C>T) and rs9459988 (T>G) and gene expression on bone marrow suppression after neoadjuvant chemotherapy for breast cancer.Methods:Breast cancer patients who received neoadjuvant chemotherapy were selected as study subjects, including 90 patients with severe bone marrow suppression and 72 patients with mild bone marrow suppression. Patient’s demographic characteristics and laboratory test indicators were collected. Two SNP sites of DLL1, rs2738822 and rs9459988, were genotyped by capillary electrophoresis and section analysis (SNaPshot) . The relative mRNA expression of DLL1 gene was detected by quantitative reverse polymerase chain reaction (QRT-PCR) method.Results:For The rs2738822 of DLL1 gene, the genotype distribution difference between severe and mild bone marrow suppression groups was statistically significant ( χ2=8.622, P=0.013) . Compared with CC genotype, CT and TT genotype carriers had a higher risk of severe bone marrow suppression, with an OR value of 2.746 (1.335-6.882) and 3.054 (1.282-8.143) , respectively. The dominant model results showed that TT OR CT carriers had a significantly higher risk of severe bone marrow suppression than THOSE with CC genotype [ OR=2.976 (1.231-4.963) ]. For rs9459988, there was no significant difference in genotype distribution between severe bone marrow suppression group and mild bone marrow suppression group ( χ2=2.149, P=0.342) . Results of the dominant model showed that TG or GG carriers had a significantly higher risk of severe bone marrow suppression than TT carriers, with an OR value of 2.046 (1.053-5.611) . The relative mRNA expression level of DLL1 gene was 1.15±0.23 in patients with severe bone marrow suppression, which was significantly lower than that in patients with mild bone marrow suppression (2.64±0.51) ( t=6.381, P<0.001) . For rs2738822, with the increase of T allele, the relative mRNA expression level of DLL1 gene decreased gradually ( P<0.05) . For rs9459988, the relative mRNA expression level of DLL1 gene in patients with mutant allele G was also significantly lower than that in wild-type CC carriers ( P<0.05) . Conclusion:Mutations of DLL1 genes rs2738822 and rs9459988 are related to the occurrence of severe bone marrow suppression after neoadjuvant chemotherapy for breast cancer, and can be used as a genetic marker to predict the degree of bone marrow suppression after neoadjuvant chemotherapy for breast cancer patients.

ObjectiveTo evaluate the clinical effectiveness of posterolateral autograft bone graft fusion transpedicular screw system internal fixation and anterior debridement in the treatment of dorsal and lumber spinal tuberculosis. MethodsFrom March 1996 to July 2000,posterolateral autograft bone graft fusion transpedicular screw system internal fixation and anterior debridement procedures were used in 62 patients suffering from dorsal and lumber spinal tuberculosis in our department,48 of them were involved in a longitudinal study follow-up for a mean of 3.6(1.5-5.5)years postoperatively. ResultsAll patients showed successful posterolateral bone graft fusion. Among 38 cases of Pott's paraplegia, 30 were completely recovered,5 were partly recovered,the rate of recovery was 92.1%. The average immediate postoperative correction of kyphosis angle was 29.1°,the average loss of correction was only 3.2°at final follow-up.ConclusionsPosterolateral autograft bone graft fusion transpedicular screw system internal fixation and anterior debridement procedure were found helpful in strengthening the stability of the spine in dorsal and lumber spinal tuberculosis, providing successful interbody fusion and recovery of Pott's paraplegia, correcting the kyphosis, and preventing progression of kyphosis.

In recent years, clear aligner technology has been maturing and is rapidly gaining popularity in the orthodontic market for its aesthetic and removable properties. However, despite the background of its large-scale clinical application, mechanical properties of clear aligners need to be studied in depth. This paper reviews the factors influencing mechanical properties of clear aligners and the current status of research to provide evidence-based guidance for clinical application.

Objective To evaluate the feasibility and safety of a delivery pathway for the performance of percutaneous left atrial appendage (LAA) occlusion in experimental canine models. Methods Transseptal puncture was performed via femoral vein approach under fluoroscopic and angiographic guidance in 12 experimental dogs. A pigtail catheter was advanced into the left atrium (LA), which was followed by LA angiography. The diameters of the neck of LAA were measured on LAA angiogram obtained in appropriate projection. After the delivery sheath was advanced along the wire into LA, a pigtail catheter was inserted into the ostium of the LAA and the sheath was then advanced over the pigtail into the LAA. LAA angiography was then performed through the delivery sheath to confirm the position of the delivery sheath. One hour after the procedure both electrocardiography (ECG) and transthoracic echocardiography (TTE) were carried out in five dogs to check the results, immediately after which the five dogs were sacrificed to macroscopically observe the damages of the puncture site of inter-atrial septum as well as inside the LA and LAA. One hour and 2 weeks after the procedure TTE was conducted in the remaining 7 dogs and these dogs were followed up for one month. Results One dog died of pericardial tamponade during the operation. In 8 dogs the LAA was clearly displayed in the projection position of right anterior oblique (RAO) 30°/cranial (CRA) 20°,while in 3 dogs the LAA was well visualized in the projection position of RAO 30° , and in one dog in the projection position of RAO 30°/caudal (CAU) 20°. The diameter of LAA neck was (13.6 ± 5.2) mm. The delivery sheath was safely advanced into the LAA along the pigtail catheter in all dogs, and no air embolism, thrombus or pericardial tamponade occurred. Hematoma at puncture point of groin occurred in 2 dogs, which was absorbed through pressure dressing. Macroscopic examination of the heart performed immediately after the operation showed that no bloody pericardial effusion was found, and mild hematoma at posterior wall of LA was seen in one dog and mild damage of the upper-margin intima of LAA was noted in 2 dogs. The mean fluoroscopy time was (10.1 ± 2.5) minutes and the mean operation time was (58 ± 12) minutes. TEE showed no pericardial effusion 2 weeks after the procedure. During the follow-up period of one month no sudden death, stroke or infection occurred. Conclusion This method of placing the delivery sheath into the LAA is clinically safe and effective, and it can reliably establish a pathway to advance the LAA occluder into LAA.

Objective:To investigate the expression of miR-211-5p in peripheral blood of patients with myelosuppression after neoadjuvant chemotherapy for breast cancer and its effect on Notch signaling pathway by targeting cyclooxygenase 2 (COX2) gene Regulation mechanism.Methods:From Jan. 2018 to Jan. 2021, 185 breast cancer patients who received neoadjuvant chemotherapy in Linyi People’s Hospital for the first time were included as the research objects. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the mRNA expression levels of miR-211-5p, COX2 gene and Notch signaling pathway related genes (Notch1, Jagged1 and Hes1) . The miR-211-5p mimic, inhibitor, mimic NC, and inhibitor NC were transfected into SD rat bone marrow mesenchymal stem cells, and the mRNA expression of miR-10a-3p and COX2 genes was detected by qRT-PCR for 48 hours. Western blot method was used to detect the protein expression levels of Notch signaling pathway related genes.Results:The relative expression of miR-211-5p in patients with severe myelosuppression was 2.41±0.32, which was significantly higher than that in patients with mild myelosuppression (1.53±0.18) ( t=6.385, P<0.001) ; The relative expression of COX2 gene mRNA in patients with severe myelosuppression was 3.64±0.74, which was significantly lower than that in patients with mild myelosuppression (5.37±1.02) ( t=7.469, P<0.001) . In patients with severe myelosuppression, there was a significant negative correlation between miR-211-5p and COX2 gene mRNA levels ( r=-0.694, P=0.006) . The results of the dual luciferase report experiment confirmed that COX2 was the target gene of miR-211-5p. The relative expression of Notch1, Jagged1, and Hes1 mRNA in peripheral blood of patients with severe myelosuppression were 2.35±0.41, 2.76±0.46 and 3.04±0.52, respectively, which were significantly lower than those in patients with mild myelosuppression (4.12±0.63, 4.53±0.58 and 5.12±0.67) ( t=5.367, 6.114 and 6.135, respectively, P<0.001) . After transfecting SD rat bone marrow mesenchymal stem cells with miR-211-5p mimics and inhibitors, the relative expression of miR-211-5p in the mimic group was 3.46±0.49, significantly higher than that in the mimic NC group (2.24±0.32) The relative expression of miR-211-5p in the inhibitor group was (1.28±0.19) and (2.33±0.37) inhibitor NC group ( P<0.001) , while the relative expression of miR-211-5p in the inhibitor group was significantly lower than that in the other three groups ( P<0.001) . The mRNA expression of COX2 gene in mimic group was 2.73±0.36, which was significantly lower than that in mimic NC group (4.05±0.59) , inhibitor group (6.15±0.86) and inhibitor NC group (4.18±0.65) ( P<0.001) , while mRNA expression of COX2 gene in the inhibitor group was significantly higher than that in the other three groups ( P<0.001) . The expression of Notch1, Jagged1, and Hes1 in the inhibitor group was significantly increased, while the expression of Notch1, Jagged1, and Hes1 in the mimic group was significantly decreased. Conclusion:The expression level of miR-211-5p in peripheral blood of severe myelosuppressed patients with breast cancer after neoadjuvant chemotherapy is significantly increased, and the Notch signaling pathway can be inhibited by targeted down-regulation of COX2 gene expression.

Objective To explore an overcorrection quantization method and related influencing factors through analyzing relationships between the achieved and preset intrusion values of mandibular anterior teeth with clear aligners.Methods Twenty pa-tients receiving Invisalign were recruited.The relative intrusion values in the ClinCheck software were recorded as the preset intrusion.The achieved intrusion values were measured through the digital model superimposition.Statistical analysis was conducted to assess the differences and linear relationships between the preset and achieved intrusion values,and investigate the effect of related factors such as intrusion amounts on the intrusion efficiency.Results For the mandibular anterior teeth,the mean intrusion efficiency was 62.2%,with the highest in the central incisors and the lowest in the canines.The intrusion amounts,incisors labial inclinations,and canine at-tachment types affected the intrusion efficiency.The differences between the preset and achieved values were significant,and the linear relationship existed.The formula of the intrusion overcorrection for the mandibular anterior teeth is"Z=(W-0.110)/0.533-W".Z re-presents the overcorrection and W represents the ideal intrusion.Conclusion The preset intrusion values in the treatment protocol could not be fully achieved.Moreover,correction should be designed in cases of mandibular canine intrusion,large amountsof intru-sion,orlingually inclined incisors.Compared to the optimized attachments,the vertical rectangular attachments on the mandibular ca-nines could improve the efficiency.

Objective To explore the effect of melatonin(MT)-modified PEEK implant assisted by polydopamine(PDA)coating on osteointegration in osteoporotic rats.Methods MT was adhered to PEEK implants with PDA coating as carrier.The physicochemical properties of the materials were analyzed by SEM image,water contact angle,FTIR and protein adsorption experiment.OVX-rBMSCs were inoculated on the surface of PEEK sheet and cultured.The cytoskeleton was stained and cell adhesion morphology was observed.Cell proliferation activity was evaluated by CCK-8 assay;key enzyme activities for osteogenic differentiation were analyzed by ALP stai-ning,and expression levels of osteoblast-related genes COL-1,Runx2,OPN,OCN,BMP-2 and ALP were detected by quantitative real-time PCR.In addition,implants were implanted into the femur of osteoporotic rats and bone volume on the implant surface was de-tected and quantified by Micro-CT.Results MT was successfully loaded on PEEK;the cell adhesion was better,and the proliferation activity and osteogenic differentiation ability were significantly higher than those of control group(P＜0.01).In the rat osteoporosis mod-el,there was more new bone formation around the modified PEEK implant(P＜0.01).Conclusion MT-modified PEEK implants have excellent biocompatibility and improve osteointegration in an osteoporotic environment.

Objective To study the differences in features of event-related potentials(ERPs)and target detection accuracy between five brain regions(frontal,temporal,central,parietal,and occipital)in target detection tasks based on rapid serial visual presentation(RSVP)brain computer interface(BCI)under six target concealment conditions.Methods Twelve participants were selected for the study,whose scalp electroencephalogram(EEG)signals were collected under the six concealment conditions using a NeuroScan SynAmps2 EEG acquisition system.The ERP waveforms,P300 amplitudes and latencies,among other things,were compared across the five brain regions.The hierarchical discriminant component analysis(HDCA)algorithm was used to classify the EEG signals while the differences in classification accuracy were probed across the five brain regions.Results(1)Under the six concealment conditions,target images elicited distinct ERP waveforms in all the five brain regions;(2)For P300 amplitudes,the temporal region exhibited the smallest values;(3)Regarding P300 latencies,the parietal and central regions showed longer durations than other brain regions(except for small camouflage and small occlusion conditions);(4)In terms of classification accuracy,the parietal and central regions outperformed other brain regions(except for the large camouflage condition).Conclusion The selection of parietal and central channels can offer a new perspective for enhancing the performance in concealed target detection based on RSVP-BCI,and is expected to spark new ideas for the design of miniaturized,simple and wearable BCI devices.