Research on detection of different metallographic structures of high speed wheel steel based on laser-induced breakdown spectroscopy.

The laser-induced breakdown spectroscopy (LIBS) experimental platform was applied to obtain LIBS spectral the data of 10 CL60 wheel steel samples. The principle component analysis (PCA) was used to preliminarily analyze the macroscopic characteristics of LIBS spectral data. With the spectral intensity and spectral intensity combined with spectral intensity ratio as variables, three spectral correction methods including median filtering, baseline correction and multiple scattering correction (MSC) were used for pretreatment. And the support vector machine (SVM) qualitative model was established to determine the metallographic structure. It was found that the SVM model established by using the pre-processed data of MSC as the input variable has the best effect. The accuracy rate of calibration set is 100%, and the accuracy rate of prediction set is 98.4%. The research has shown that LIBS combined with SVM model can be used for discriminant analysis of different metallographic structures of train wheel steel.

Susceptibilities of human ACE2 genetic variants in coronavirus infection

The COVID-19 pandemic, caused by SARS-CoV-2, has resulted in more than 1603 million cases worldwide and 3.4 million deaths (as of May 2021), with varying incidences and death rates among regions/ethnicities. Human genetic variation can affect disease progression and outcome, but little is known about genetic risk factors for SARS-CoV-2 infection. The coronaviruses SARS-CoV, SARS-CoV-2 and HCoV-NL63 all utilize the human protein angiotensin-converting enzyme 2 (ACE2) as the receptor to enter cells. We hypothesized that the genetic variability in ACE2 may contribute to the variable clinical outcomes of COVID-19. To test this hypothesis, we first conducted an in silico investigation of single-nucleotide polymorphisms (SNPs) in the coding region of ACE2 gene. We then applied an integrated approach of genetics, biochemistry and virology to explore the capacity of select ACE2 variants to bind coronavirus spike protein and mediate viral entry. We identified the ACE2 D355N variant that restricts the spike protein-ACE2 interaction and consequently limits infection both in vitro and in vivo. In conclusion, ACE2 polymorphisms could modulate susceptibility to SARS-CoV-2, which may lead to variable disease severity.

Comparative analysis reveals the species-specific genetic determinants of ACE2 required for SARS-CoV-2 entry

Coronavirus interaction with its viral receptor is a primary genetic determinant of host range and tissue tropism. SARS-CoV-2 utilizes ACE2 as the receptor to enter host cell in a species-specific manner. We and others have previously shown that ACE2 orthologs from New World monkey, koala and mouse cannot interact with SARS-CoV-2 to mediate viral entry, and this defect can be restored by humanization of the restrictive residues in New World monkey ACE2. To better understand the genetic determinants behind the ability of ACE2 orthologs to support viral entry, we compared koala and mouse ACE2 sequences with that of human and identified the key residues in koala and mouse ACE2 that restrict viral receptor activity. Humanization of these critical residues rendered both koala and mouse ACE2 capable of binding the spike protein and facilitating viral entry. The single mutation that allowed for mouse ACE2 to serve as a viral receptor provides a potential avenue for the development of SARS-CoV-2 mouse model.

Stathmin overexpression is associated with growth, invasion and metastasis of lung adenocarcinoma.

Stathmin has been investigated as a tumor biomarker because it appear to be associated with tumorigenesis; however, the effect of stathmin in lung adenocarcinoma (LAC) remains poorly understood. The purpose of this study was to examine the expression of stathmin in lung adenocarcinoma, and to disclose the relationship between them. The expression of stathmin was examined by RT-PCR, IHC and Western blot. Furthermore, small interfering RNA (shRNA)-mediated silencing of stathmin was employed in LAC cells to investigate cell proliferation, invasion and apoptosis. In this study, we showed that overexpression of stathmin was significantly associated with poorly differentiated, lymph node metastasis and advance TNM stages of lung adenocarcinoma. And silencing of stathmin expression inhibited the proliferation, migration and invasion of lung adenocarcinoma PC-9 cells, and retarded the growth of PC-9 cells xenografts in nude mice. Additionally, the anticarcinogenic efficacy of stathmin silencing might be involved in P38 and MMP2 signaling pathways. In conclusion, these results showed that stathmin expression was significantly up-regulated in LAC, which may act as a biomarker for LAC. Furthermore, silence of stathmin inhibiting LAC cell growth indicated that stathmin may be a promising molecular target for LAC therapy.

Correlation between Lung Function and Peripheral Interleukin Expression of Mycoplasma Pneumonia Children / 现代生物医学进展

Objective:To investigate the correlation between IL-10 and I1-17 expression levels in Mycoplasma pneumoniae pneumonia (MPP) and lung function.Methods:70 patients were included in this study.According to wheezing or not,they were divided into wheezing group and non-wheezing group.Another 30 healthy children were taken as a control group.After taking fasting blood 5ml,the serum IL-10 and IL-17 expression levels were detected by ELISA.The forced expiratory volume in one second (PEV1),peak expiratory flow (PEF) and forced vital capacity (FEV1 / FVC) of all subjects were detected.Results:The IL-10 expression level of the wheezing group were significantly different with that of the control group (P＜0.05) and that of the non-wheezing group (P＜0.05).The 1L-17 expression level of the wheezing group also had significant difference (P＜0.05) with that of the control group and non-wheezing group (P＜0.05).The IL-10 expression levels of wheezing and non-wheezing group all were lower than that of the control group.Whereas the IL-17 expression levels of wheezing and non-wheezing group all were higher than that in the control group.In addition,patients in wheezing group had higher PEV1,PEF,PVE1/FVC values than those in non-wheezing group,with significant difference (P＜0.05).The serum level of IL-10 expression of Mycoplasma pneumonia patients was positively correlated with PEV1,PEF and PVE1/FVC,while the serum level of IL-17 expression of Mycoplasma pneumonia patients was negatively correlated with PEV1,PEF and PVE1/FVC.Conclusion:The serum levels of IL-17 and IL-10 expression of Mycoplasma pneumonia children had close correlation with their pulmonary function.

Effect of sodium butyrate combined with TRAIL on biological behaviors of lung cancer stem cells / 中国组织工程研究

BACKGROUND:Sodium butyrate, a histone deacetylase inhibitor, can inhibit cell proliferation, and induce apoptosis and differentiation of various cancer cells. However, the role of sodium butyrate combined with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on lung cancer stem cells remains unclear. OBJECTIVE:To explore the effect of sodium butyrate combined with TRAIL on biological behaviors of lung cancer stem cells. METHODS:Magnetic bead separation was used to separate lung cancer stem cells (CD133+) from human lung adenocarcinoma A549 cells. After the lung cancer stem cells were treated with simple DMEM/F12, DMEM/F12 containing sodium butyrate (5 mmol/L), TRAIL (50 μg/L) or sodium butyrate combined with TRAIL, the cell proliferation within 96 hours of culture was determined by MTT assay; the apoptosis within 24 hours of culture was measured by flow cytometry; the cell migration within 48 hours of culture was detected by cell scratch test; the expression levels of pluripotent transcription factors (Oct4, Sox2 and Nanog) within 48 hours of culture were detected using western blot analysis. RESULTS AND CONCLUSION:The CD133+ lung cancer stem cells were successfully enriched from human lung adenocarcinoma A549 cells. MTT assay showed that sodium butyrate and TRAIL significantly inhibited the proliferation of lung cancer stem cells (P< 0.05), and the combination effect was even stronger (P < 0.05). Results from flow cytometry analysis and scratch test showed that sodium butyrate or TRAIL induced apoptosis and inhibited cell migration of lung cancer stem cells (P < 0.05), and the combination of sodium butyrate and TRAIL showed a stronger effect (P < 0.05). In addition, the expression levels of Oct4, Sox2 and Nanog were significantly down-regulated by sodium butyrate (P < 0.05), TRAIL or sodium butyrate combined with TRAIL, and the combination effect was stronger (P < 0.05). In conclusion, sodium butyrate and TRAIL have synergistic effects on lung cancer stem cells, indicating a new way for treatment of lung cancer.

Argon plasma coagulation for Barrett's esophagus:a systematic review / 西安交通大学学报(医学版)

Objective To assess the efficacy and safety of argon plasma coagulation(APC) in treating patients with Barrett's esophagus.Methods Two reviewers independently searched the Cochrane Library(Issue 2,2008),MEDLINE(January 1948 to November 2008),and CNKI(January 1999 to November 2008),respectively.The quality of the included studies was assessed according to the guidance in the Cochrane Handbook of systematic reviews of interventions.Results Six randomized controlled trials involving 253 patients with Barrett's esophagus met the inclusion criteria and were included.One trial reported that the ablation rate of patients in the APC group was significantly higher than that in the endoscopic surveillance group.Followed up one year,the ablation rate in APC group was 63% compared with 15% in the control group(P