Dry Sliding Tribological Behaviors of Electrodeposited Ni-GO/SiC Composite Coating on the 2218 Aluminum Alloy

Electrodeposition has attracted tremendous interest in functional coatings due to its advantages of high efficiency, inexpensiveness and ease of implementation. In this work, nickel graphene oxide (Ni-GO), nickel silicon carbide (Ni-SiC) and nickel graphene oxide/silicon carbide (Ni-GO/SiC) composite coatings were electrodeposited on the 2218 aluminum alloy (2218AlA) substrate. The microstructure, microhardness, bonding strength and tribological behaviors of the composite coatings were carried out. According to the results obtained, the composite coatings were dense and compact, with no visible defects and microcracks, and well bonded to 2218AlA substrate. The microhardness of composite coatings was significantly increased compared to that of the 2218AlA substrate. The microhardness of Ni-SiC composite coating was the highest, reaching 3.14 times that of the 2218AlA substrate. The friction response time, friction coefficient and wear rate of the composite coatings were obviously lower. For the Ni-GO composite coating, the average friction coefficient is the smallest at 45.35% of the 2218AlA substrate, while the wear rate is the smallest at 46.97% of the 2218AlA substrate. However, the comprehensive tribological performances of the Ni-GO/SiC composite coating were superior. The abrasive and adhesive wear were the main wear mechanisms of composite coatings, but the degree of damage was different.

Experimental study on thioredoxin redox inhibitor 1-methylpropyl 2-imidazolyl disulfide promoting apoptosis of multiple myeloma cells in vitro and in vivo

OBJECTIVE

  To explore the in vitro and in vivo experimental study of thioredoxin-1(Trx1) inhibitor 1-methylpropyl 2-imidazolyl disulfide (PX-12) promoting multiple myeloma H929 cell apoptosis, investigate the relationship between the inhibitory effect of PX-12 on H929 cells and reactive oxygen species (ROS).

MATERIALS AND METHODS

Inhibition of PX-12 on H929 cells in relation to reactive oxygen species (ROS), cell cycle, and apoptosis were assessed by flow cytometry. ELISA kit, IVIS Imaging, Hematoxylin and eosin (H&E) staining and immunohistochemical staining assessment were applied to assess the anti-myeloma effect in the SCID mice model established by H929EL cells.

RESULTS

PX-12 inhibited proliferation of H929 cells performed time and dose dependent style. Furthermore, it significantly induced a G2/M phase arrest of the cell cycle in H929 cells. It also increased intracellular ROS and caspase-3 activity in H929 cells indicating that cells have undergone apoptosis. There was an almost 3-5-fold decrease in tumor viability measured by the Living-Imaging system after 21 and 28 days after PX-12 injection compared with the control group. Importantly, PX-12 caused significant decrease in expression of Kappa chain in vivo assessed by immunohistochemical staining.

CONCLUSIONS

The results suggest that PX-12 may be a potential strategy for the treatment of MM, and the inhibition of TRX-1 in the treatment of myeloma deserves further research.

GPI Is a Prognostic Biomarker and Correlates With Immune Infiltrates in Lung Adenocarcinoma

Background

Glucose-6-phosphate isomerase (GPI) plays an important role in glycolysis and gluconeogenesis. However, the role of GPI in lung adenocarcinoma (LUAD) remains unclear.

Methods

All original data were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and integrated via R 3.2.2. GPI expression was explored with TCGA, GEO, and Oncomine databases. Immunohistochemistry staining was used to analyze GPI expression in clinical specimens. The correlations between GPI and cancer immune characteristics were analyzed via the TIMER and TISIDB databases. GPI-specific siRNAs were used to verify the role of GPI expression on cell proliferation and cell cycle distribution.

Results

In general, GPI is predominantly overexpressed and has reference value in the diagnosis and prognostic estimation of LUAD. Upregulated GPI was associated with poorer overall survival, clinical stage, N stage, and primary therapy outcome in LUAD. Mechanistically, we identified a hub gene that included a total of 56 GPI-related genes, which were tightly associated with the cell cycle pathway in LUAD patients. Knockdown of GPI induced cell proliferation inhibition and cell cycle arrest. GPI expression was positively correlated with infiltrating levels of Th2 cells and regulatory T cells (Tregs); in contrast, GPI expression was negatively correlated with infiltrating levels of CD8⁺ T cells, central memory T cells, dendritic cells, macrophages, mast cells, and eosinophils. GPI was negatively correlated with the expression of immunostimulators, such as CD40L, IL6R, and TMEM173, in LUAD.

Conclusion

GPI may play an important role in the cell cycle and can be used as a prognostic biomarker for determining the prognosis and immune infiltration in LUAD.

Plasma metabolomics in perioperative period of defect repair in patients with pulmonary arterial hypertension associated with congenital heart disease

Background

The pathophysiological alterations in response to shunt correction in patients with pulmonary arterial hypertension associated with congenital heart disease (CHD-PAH) is still not clear.

Purpose

To explore the dynamic plasma metabolite profiling and its relationship with clinical characteristics in patients with CHD-PAH during the perioperative period of defect repair.

Methods

Plasma samples from 13 patients with CHD-PAH were harvested at four time points: before cardiopulmonary bypass (CPB) after anesthesia (Pre), immediately after CPB (T0), 24 h (T24), and 48 h (T48) after defect repair. The untargeted metabolomics strategy based on UPLC Q-TOF MS was used to detect the metabolites. Clinical measures were recorded at indicated time points.

Results

The sample distribution at four time points was well separated (Figure 1A, B). 193 metabolites were distinguished at different time points according to Variable Important in Projection (VIP) score (Figure 1C), enriched in pathways such as carnitine synthesis, phospholipid biosynthesis and oxidation of branched chain fatty acids (Figure 2A). 17 metabolites alterations were significantly correlated with gradients in mean pulmonary arterial pressure (mPAP) at T48 versus Pre, indicative of the response to defect correction (Figure 2B). Intriguingly, 4 out of the 17 (23.5%) metabolites including propionylcarnitine, butenylcarnitine, isobutyryl-L-carnitine and hexanoylcarnitine were enriched in oxidation of branched chain fatty acids. They were increased at both T24 and T48 (all P<0.05 except propionylcarnitine with P<0.05 at T24) (Figure 2C).

Conclusions

This is the first study to show the altered metabolic profiles of CHD-PAH patients in perioperative period of defect repair. Metabolites that respond to shunt correction could be a suitable non-invasive marker and would be of great value in disease monitoring and evaluating future therapeutic interventions.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): 13th Five-Year Plan–Precise Medicine–Key Research and Development Program–Clinical Cohort of Rare Disease; National Natural Science Foundation of China Figure 1. Overall analysis of metabolitesFigure 2. Shunt correction associated metabolites

Post-procedure anticoagulation in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Background

Post-procedural anticoagulation (PPAC) after primary percutaneous coronary intervention (pPCI) in patient with ST-segment elevation myocardial infarction (STEMI) may prevent recurrent ischemic events but may increase the risk of bleeding. No consensus has been reached on PPAC use.

Methods

Using data from the CCC-ACS registry, conducted between 2014 and 2019, we stratified all STEMI patients who underwent pPCI according to the use of PPAC or not. Inverse probability of treatment weighting (IPTW) and Cox proportional hazards model with hospital as random effect were used to analyze differences in in-hospital clinical outcomes: the primary efficacy endpoint was mortality, and the primary safety endpoint was major bleeding.

Results

Of 34,826 evaluable patients 26,272 (75.4%) were treated with PPAC, and were on average younger, more stable at admission with lower bleeding risk score, more likely to have comorbidities and multivessel disease, and more often treated within 12 hours of symptom onset than those without PPAC. After IPTW adjustment for baseline differences, PPAC was associated with significantly reduced risk of in-hospital mortality (0.9% vs. 1.8%; hazard ratio (HR): 0.62 [95% confidence interval 0.43, 0.89]; p<0.001) and a nonsignificant difference in risk of in-hospital major bleeding (2.5% vs. 2.2%; HR: 1.05 [0.83, 1.32]; p=0.14).

Conclusions

PPAC in STEMI patients after pPCI was associated with reduced mortality without increasing major bleeding complications. Dedicated randomized trials with contemporary STEMI management are needed to confirm these findings.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The Improving Care for Cardiovascular Disease in China – Acute Coronary Syndrome (CCC-ACS) project is a collaborative study of the American Heart Association (AHA) and the Chinese Society of Cardiology (CSC). The AHA has been funded by Pfizer and AstraZeneca for quality improvement initiatives through an independent grant. In-hospital clinical outcomes

Virtual bronchoscopy-guided lung SAbR: dosimetric implications of using AAA versus Acuros XB to calculate dose in airways

In previous works, we showed that incorporating individual airways as organs-at-risk (OARs) in the treatment of lung stereotactic ablative radiotherapy (SAbR) patients potentially mitigates post-SAbR radiation injury. However, the performance of common clinical dose calculation algorithms in airways has not been thoroughly studied. Airways are of particular concern because their small size and the density differences they create have the potential to hinder dose calculation accuracy. To address this gap in knowledge, here we investigate dosimetric accuracy in airways of two commonly used dose calculation algorithms, the anisotropic analytical algorithm (AAA) and Acuros-XB (AXB), recreating clinical treatment plans on a cohort of four SAbR patients. A virtual bronchoscopy software was used to delineate 856 airways on a high-resolution breath-hold CT (BHCT) image acquired for each patient. The planning target volumes (PTVs) and standard thoracic OARs were contoured on an average CT (AVG) image over the breathing cycle. Conformal and intensity-modulated radiation therapy plans were recreated on the BHCT image and on the AVG image, for a total of four plan types per patient. Dose calculations were performed using AAA and AXB, and the differences in maximum and mean dose in each structure were calculated. The median differences in maximum dose among all airways were ≤0.3Gy in magnitude for all four plan types. With airways grouped by dose-to-structure or diameter, median dose differences were still ≤0.5Gy in magnitude, with no clear dependence on airway size. These results, along with our previous airway radiosensitivity works, suggest that dose differences between AAA and AXB correspond to an airway collapse variation ≤0.7% in magnitude. This variation in airway injury risk can be considered as not clinically relevant, and the use of either AAA or AXB is therefore appropriate when including patient airways as individual OARs so as to reduce risk of radiation-induced lung toxicity.

[Therapeutic mechanism of the Mongolian medicine Qiwei Qinggan Powder against liver fibrosis based on UHPLC-TOF-MS combined with network pharmacological methods]

OBJECTIVE

To elucidate the chemical composition of the Mongolian medicine Qiwei Qinggan Powder and explore its key targets, related pathways and its therapeutic mechanism for liver fibrosis.

METHODS

UHPLC-TOF-MS was used to analyze the composition of Qiwei Qinggan Powder. The therapeutic targets of Qiwei Qinggan Powder were screened in Swiss Target Prediction database, and liver fibrosis-related targets were screened in TTD and GeneCards databases to identify the anti-fibrosis targets of Qiwei Qinggan Powder by intersection using Venny.2.1.0. The protein interaction was analyzed using STRING database, the GO functions and KEGG pathways were analyzed on the Metascape platform, and the core targets and active components were verified by molecular docking using AutoDock software. The therapeutic mechanism of Qiwei Qinggan Powder against liver fibrosis was verified in rat models and cell experiment.

RESULTS

We identified a total of 45 chemical constituents in Qiwei Qinggan Powder, including flavonoids, alkaloids, coumarins, terpenes, phenols and fatty acids. Network pharmacological analysis identified 62 targets of Qiwei Qinggan Powder, including 10 core targets. GO enrichment analysis suggested that the therapeutic effect of Qiwei Qinggan Powder was mediated by biological processes (BP), cell components (CC) and molecular functions (MF). KEGG enrichment results showed that PI3K/Akt, Rap1, MAPK, AMPK and PPAR were all pathways associated with liver fibrosis. Molecular docking showed that quercetin, luteolin and kaempferol could bind to Akt1, PIK3R1 and MAPK1, respectively. In rat models of liver fibrosis, treatment with Qiwei Qinggan Powder significantly suppressed proliferation of fibrous tissues and inflammatory cell infiltration to improve fibrosis in the liver tissue. Western blotting demonstrated that Qiwei Qinggan Powder significantly decreased the expressions of the Liver fibrosis markers including α-SMA, Collagen1, PI3K and Akt (P < 0.01). In vitro cell experiment, Qiwei Qinggan Powder-containing serum obviously promoted apoptosis of HSC-T6 cells.

CONCLUSION

The therapeutic effect of Qiwei Qinggan Powder against liver fibrosis is mediated by multiple components, targets and channels, and its mechanism may involve the regulation of PI3K, Akt and other key targets and modulation of cell apoptosis and energy metabolism.

[Clinicopathological and molecular features of small round cell sarcoma of bone and soft tissue: a study of 72 cases]

Objective: To investigate the clinicopathological, immunohistochemical and molecular features of small round cell sarcoma (SRCS) of the bone and soft tissue, and to compare the diagnostic value of different techniques. Methods: Seventy-two cases of SRCS of the bone and soft tissue diagnosed at People's Hospital, Peking University from January 2016 to March 2020 were recruited and retrospectively analyzed for pathological morphology, immunophenotype and fluorescence in situ hybridization (FISH) data. Next generation sequencing (NGS) was performed on 13 difficult cases. Results: In the study cohort, the patients ranged in age from 4-55 years, with a male predominance. The most Ewing's sarcomas and osteosarcomas occurred in the bone, while CIC-rearranged sarcomas, BCOR-rearranged sarcoma, synovial sarcoma, extraskeletal myxoid chondrosarcoma and FUS-NFATc2 rearranged sarcoma occurred in soft tissue. Histologically, all cases were composed predominantly of small round cells. Most cases were positive for vimentin and CD99, and showed a variable reactivity for neurogenic markers. Muscle marker and epithelial marker were negative for most cases. Combined with clinical features, histopathologic findings, immunophenotype, FISH and NGS, we diagnosed 46 Ewing sarcomas, 14 osteosarcomas, 3 CIC-rearranged sarcomas, 1 BCOR-rearranged sarcoma, 1 synovial sarcoma, 1 clear cell soft tissue sarcoma, 1 extraskeletal myxoid chondrosarcoma, 1 FUS-NFATc2 rearranged sarcoma, and 4 undifferentiated small round cell sarcomas. Conclusions: SRCS of bone and soft tissue is a group of malignant mesenchymal tumors based on morphological features. Most cases can be diagnosed with a combination of clinical characteristics, morphological features and immunohistochemical phenotype, while some cases require such further tests as FISH and NGS technologies, and NGS can be useful in diagnosing and categorizing SRCS.

[Platelet-rich plasma alleviates myocardial ischemia-reperfusion injury in rats]

OBJECTIVE

To investigate the protective effect of platelet-rich plasma (PRP) against acute myocardial ischemiareperfusion (IR) injury and the possible mechanism.

OBJECTIVE

Aortic blood samples were collected from 10 SD rats to prepare PRP, in which the concentrations of platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-β1 (TGF-β1) were measured. Cell models of IR injury were established in primary cultures of neonatal SD rat cardiomyocytes by exposing the cells to 3 h of hypoxia. The cells were then reoxygenated and co-cultured with 1%, 5%, 10%, and 20% volume of PRP for 12 h, and the changes in cell viability was assessed. Immunofluorescence staining of the cardiomyocytes was performed, and the cellular expression of AMPK and its phosphorylation level were detected. The effects of PRP on the proliferation and migration of rat aortic endothelial cells (RAOECs) were examined. In a SD rat model of myocardial IR injury, 100 μL of PRP (n= 20) or normal saline (n=20) was injected at 4 sites around the ligation site immediately after cardiac reperfusion. One day after the injection, 6 rats were selected from each group for TTC staining of the myocardial tissues and measurement of troponin Ⅰ content. One week later, the cardiac function of the remaining rats was assessed by echocardiography, and HE staining of the myocardial tissues was performed. The effect of PRP treatment for 24 h on polarization of M1 and M2 macrophages was also examined by flow cytometry in RAW264.7 cells after hypoxic exposure for 3 h.

OBJECTIVE

The concentrations of PDGF-BB and TGF-β1 were significantly higher in PRP than in whole blood. Addition of 1% volume of PRP significantly reduced death of the cardiomyocytes following reoxygenation, and this effect was closely related with the activation of AMPK. Treatment with PRP obviously promoted the proliferation and migration of RAOECs. In rat models of acute myocardial IR injury, injections of PRP significantly reduced the infarct size and troponin Ⅰ concentration as compared with saline injection (P < 0.001). One week after PRP injection, the rats showed significantly improved cardiac function with a lowered level of inflammatory response in comparison with the rats with saline injection. In RAW264.7 cells with hypoxic exposure, treatment with PRP obviously decreased the number of M1 macrophages and increase the number of M2 macrophages.

OBJECTIVE

PRP can improve acute myocardial IR injury in rats by phosphorylating AMPK and regulating macrophage polarization, which produces a protective immunomodulatory effect on the ischemic myocardial tissues.

[A multi-center retrospective study of perioperative chemotherapy for gastric cancer based on real-world data]

Objective: To explore the effect of perioperative chemotherapy on the prognosis of gastric cancer patients under real-world condition. Methods: A retrospective cohort study was carried out. Real world data of gastric cancer patients receiving perioperative chemotherapy and surgery + adjuvant chemotherapy in 33 domestic hospitals from January 1, 2014 to January 31, 2016 were collected. Inclusion criteria: (1) gastric adenocarcinoma was confirmed by histopathology, and clinical stage was cT2-4aN0-3M0 (AJCC 8th edition); (2) D2 radical gastric cancer surgery was performed; (3) at least one cycle of neoadjuvant chemotherapy (NAC) was completed; (4) at least 4 cycles of adjuvant chemotherapy (AC) [SOX (S-1+oxaliplatin) or CapeOX (capecitabine + oxaliplatin)] were completed. Exclusion criteria: (1) complicated with other malignant tumors; (2) radiotherapy received; (3) patients with incomplete data. The enrolled patients who received neoadjuvant chemotherapy and adjuvant chemotherapy were included in the perioperative chemotherapy group, and those who received only postoperative adjuvant chemotherapy were included in the surgery + adjuvant chemotherapy group. Propensity score matching (PSM) method was used to control selection bias. The primary outcome were overall survival (OS) and progression-free survival (PFS) after PSM. OS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the last effective follow-up or death. PFS was defined as the time from the first neoadjuvant chemotherapy (operation + adjuvant chemotherapy group: from the date of operation) to the first imaging diagnosis of tumor progression or death. The Kaplan-Meier method was used to estimate the survival rate, and the Cox proportional hazards model was used to evaluate the independent effect of perioperative chemo therapy on OS and PFS. Results: 2 045 cases were included, including 1 293 cases in the surgery+adjuvant chemotherapy group and 752 cases in the perioperative chemotherapy group. After PSM, 492 pairs were included in the analysis. There were no statistically significant differences in gender, age, body mass index, tumor stage before treatment, and tumor location between the two groups (all P>0.05). Compared with the surgery + adjuvant chemotherapy group, patients in the perioperative chemotherapy group had higher proportion of total gastrectomy (χ(2)=40.526, P<0.001), smaller maximum tumor diameter (t=3.969, P<0.001), less number of metastatic lymph nodes (t=1.343, P<0.001), lower ratio of vessel invasion (χ(2)=11.897, P=0.001) and nerve invasion (χ(2)=12.338, P<0.001). In the perioperative chemotherapy group and surgery + adjuvant chemotherapy group, 24 cases (4.9%) and 17 cases (3.4%) developed postoperative complications, respectively, and no significant difference was found between two groups (χ(2)=0.815, P=0.367). The median OS of the perioperative chemotherapy group was longer than that of the surgery + adjuvant chemotherapy group (65 months vs. 45 months, HR: 0.74, 95% CI: 0.62-0.89, P=0.001); the median PFS of the perioperative chemotherapy group was also longer than that of the surgery+adjuvant chemotherapy group (56 months vs. 36 months, HR=0.72, 95% CI:0.61-0.85, P<0.001). The forest plot results of subgroup analysis showed that both men and women could benefit from perioperative chemotherapy (all P<0.05); patients over 45 years of age (P<0.05) and with normal body mass (P<0.01) could benefit significantly; patients with cTNM stage II and III presented a trend of benefit or could benefit significantly (P<0.05); patients with signet ring cell carcinoma benefited little (P>0.05); tumors in the gastric body and gastric antrum benefited more significantly (P<0.05). Conclusion: Perioperative chemotherapy can improve the prognosis of gastric cancer patients.

The circular RNA circPTK2 inhibits EMT in hepatocellular carcinoma by acting as a ceRNA and sponging miR-92a to upregulate E-cadherin

OBJECTIVE

Hepatocellular carcinoma (HCC) is a common malignant tumor. Increasing evidence has demonstrated that microRNAs (miRNAs) play an important role in a wide variety of cellular processes. However, there are few reports about the role and underlying molecular mechanisms of miRNAs in HCC.

PATIENTS AND METHODS

qRT-PCR and Western blots were performed to quantify the expression of miR-92a, E-cadherin, and circPTK2. Proliferation and invasion assays were performed to explore the function of miR-92a and circPTK2. A Luciferase assay was used to test the relationship between miR-92a, E-cadherin, and circPTK2.

RESULTS

In this study, we found that miR-92a was upregulated in HCC tissues and HCC cell lines. Overexpression of miR-92a enhanced cell proliferation and invasion by targeting the E-cadherin 3'UTR in HCC cells. Furthermore, we found that circPTK2 inhibited EMT by inhibiting miR-92a, preventing its ability to downregulate E-cadherin in HCC cells.

CONCLUSIONS

We identified a regulatory axis comprising circPTK2/miR-92a/E-cadherin in HCC cells that may serve as a valuable biomarker and therapeutic target for patients with HCC.

Knockdown of FOXM1 suppresses cell growth and metastasis in human laryngeal cancer via the AKT signaling pathway

OBJECTIVE

This study aims to investigate the potential regulatory effect of forkhead box M1 (FOXM1) on laryngeal carcinoma (LC) and the underlying mechanisms.

PATIENTS AND METHODS

Tumor tissues were obtained from 80 patients diagnosed with LC in our hospital. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) and Western blot analysis were used to detect the expression levels of FOXM1 in LC tissues and cell lines. Transfection of small interfering RNA (si-RNA) was conducted to knockdown the expression level of FOXM1. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and cell colony assay were conducted to measure the changes in cell proliferation capacity influenced by FOXM1. Finally, invasion and migration ability was evaluated by the transwell assay.

RESULTS

FOXM1 was found upregulated in LC tissues and cells. Transfection of FOXM1 siRNA in LC cells successfully inhibited the expression of FOXM1. The knockdown of FOXM1 resulted in reduced proliferation, invasion, and migration of LC cells. Further studies indicated that the knockdown of FOXM1 suppressed the ratio of p-AKT/AKT. Besides, the impaired proliferation, invasion, and migration of LC cells induced by FOXM1 knockdown could be counteracted by application of the AKT activator Sc79.

CONCLUSIONS

The present work demonstrated that the knockdown of FOXM1 suppressed the proliferation, invasion, and migration of LC cells by the AKT signaling pathway.

MiR-199a modulates autophagy and inflammation in rats with cerebral infarction via regulating mTOR expression

OBJECTIVE

The aim of this study was to investigate the roles of micro ribonucleic acid (miR)-199a in rats with cerebral infarction by regulating mammalian target of rapamycin (mTOR).

MATERIALS AND METHODS

A total of 36 Sprague-Dawley rats were randomly assigned into three groups, including: sham group (n=12), model group (n=12) and miR-199a mimics group (n=12). In sham group internal and external carotid arteries were exposed. The ischemia-reperfusion model was successfully established using suture embolization in the other two groups. After modeling, rats in sham group and model group were intraperitoneally injected with normal saline. However, rats in miR-199a mimics group were injected with miR-199a mimics. Following intervention for 3 d, sampling was conducted. Neurological deficit was evaluated in rats based on the Zea-Longa scoring system. Hematoxylin-eosin (HE) staining was performed to observe neuronal morphology. The expression of mTOR was detected using immunohistochemistry, and the relative expression level of tau protein was determined via Western blotting (WB). Besides, the messenger RNA (mRNA) expressions of mTOR and tau were detected by quantitative Polymerase Chain Reaction (qPCR). Finally, inflammatory factor content was measured through enzyme-linked immunosorbent assay (ELISA).

RESULTS

Model group and miR-199a mimics group exhibited a substantially higher Zea-Longa score than sham group (p<0.05). Compared with model group, the Zea-Longa score rose prominently in miR-199a mimics group (p<0.05). According to the results of HE staining, the structure of neurons in sham group was clear and intact, while the structure of neurons in model group was disordered. Meanwhile, neuronal morphology in miR-199a mimics group was significantly worse than that in model group (p<0.05). Immunohistochemistry results demonstrated that the positive expression level of mTOR was considerably upregulated in both model group and miR-199a mimics group in comparison with sham group (p<0.05). Moreover, its positive expression level in miR-199a mimics group was markedly higher that in model group (p<0.05). Based on the results of WB, model and miR-199a mimics groups exhibited a remarkably higher relative expression level of tau protein than sham group (p<0.05). However, the relative expression level of tau protein in miR-199a mimics group was prominently higher than that in model group (p<0.05). QPCR results manifested that the relative mRNA expression levels of mTOR and tau in model group and miR-199a mimics group were dramatically higher than those in sham group (p<0.05). Compared with those in model group, the relative mRNA expression levels of mTOR and tau increased significantly in miR-199a mimics group (p<0.05). ELISA results revealed that model group and miR-199a mimics group had prominently higher content of inflammatory factors than sham group (p<0.05). In addition, content of inflammatory factors in miR-199a mimics group was considerably higher than that in model group (p<0.05).

CONCLUSIONS

MiR-199a modulates mTOR expression to exert important regulatory effects on the autophagy and inflammation in rats with cerebral infarction.

[Geometric model of reduction in basilar invagination with atlantoaxial dislocation and its clinical application]

Objectives: To establish a geometric model of the atlantoaxial dislocation and basilar invagination reduction,and examine its value for clinical application. Methods: A retrospective analysis of 35 patients with atlantoaxial dislocation and basilar invagination admitted to the Department of Neurosurgery,First Affiliated Hospital of Chongqing Medical University from May 2018 to May 2020 was conducted.There were 5 males and 30 females,aged (48±15) years(range: 19 to 69 years). The geometric model of the atlantoaxial reduction was established based on the mid-sagittal section of the cervical spine. The relevant data were calculated according to the geometric model before operation,and the fusion cage of the corresponding height was placed into C_1-2 facet joint of patient for quantitative reduction. The theoretical reset value, actual reset value, postoperative symptoms and complications were collected. The paired t-test was used to compare the difference between theoretical and actual reset value to verify the reliability of the geometric model. Results: The theoretical vertical reduction distance of all patients was (5.79±2.96) mm(range:1.52 to 10.96 mm),and the actual vertical reduction distance was (7.43±2.96)mm(range: 1.40 to 12.77 mm),and there was no statistical difference between them(t=-1.96,P=0.069).The theoretical reduction angle was (10.80±2.24)°(range: 7.09 to 14.86°), the actual reduction angle was (10.64±7.00)°(range: 3.50 to 20.50°),and there was no statistical difference between them (t=0.09, P=0.933). At 6 months follow-up, 35 patients achieved satisfactory atlanto-axial joint fusion, and the symptoms were relieved. No internal fixation system displacement, fracture, wound infection and other complications occurred. Conclusion: This geometric model can estimate the vertical reduction distance and the reduction angle of the axial before operation,and provide a reference for the height of the fusion cage so as to avoid under or over-reduction.

[Analysis on the status quo and influencing factors of career management of operating room nurses]

Objective: To investigate the status quo of operating room nurse career management in Shandong Province, and to analysis its influencing factors. Methods: In February 2019, 1418 operating room nurses in Shandong province were selected to investigate their general situation and current status of career management and analyze possible influencing factors by using the General Information Questionnaire, the Career Management Questionnaire for Nurses and the Career Planning Questionnaire for Nurses. Results: The total score of organizational career management scale was (48.24±11.12) points, with the score of dimension from high to low as valueing training (12.64±2.54) points, justice in promotion (12.11±3.04) points, providing career information (12.10±3.21) points, promotion in career self-development (11.39±3.46) points. The total score of organizational career planning scale was (43.33±9.00) points. Multiple liner regression analysis showed that career planning (β=0.742, P<0.001) , hospital grade (β=-0.068, P<0.001) and age (β=-0.065, P<0.001) were influencing factors of operating room nurse career management which could explained 57.1% of the variation (F=630.596, P<0.001) . Conclusion: Career management of operating room nurse is at a medium level, the scores of different dimensions are not balanced.Career planning score, hospital level, age and other factors affect the career management score of operating room nurses.