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Extracellular matrix (ECM) stiffness has profound effects on the regulation of cell functions. DNA methylation is an important epigenetic modification governing gene expression. However, the effects of ECM stiffness on DNA methylation remain elusive. Here, it is reported that DNA methylation is sensitive to ECM stiffness, with a global hypermethylation under stiff ECM condition in mouse embryonic stem cells (mESCs) and embryonic fibroblasts compared with soft ECM. Stiff ECM enhances DNA methylation of both promoters and gene bodies, especially the 5' promoter regions of pluripotent genes. The enhanced DNA methylation is functionally required for the loss of pluripotent gene expression in mESCs grown on stiff ECM. Further experiments reveal that the nuclear transport of DNA methyltransferase 3-like (DNMT3L) is promoted by stiff ECM in a protein kinase C α (PKCα)-dependent manner and DNMT3L can be binding to Nanog promoter regions during cell-ECM interactions. These findings unveil DNA methylation as a novel target for the mechanical sensing mechanism of ECM stiffness, which provides a conserved mechanism for gene expression regulation during cell-ECM interactions.

Objective To compare the differences of energy spectrum CT between small cell lung cancer(SCLC)with mediastinal lymph node metastasis and mediastinal sarcoidosis.Methods Twenty-five SCLC patients with mediastinal lymph node metastasis(SCLC group)and 26 patients with mediastinal sarcoidosis(sarcoidosis group)confirmed by bronchoscopy and biopsy in Tangshan People's Hospital from January 2018 to June 2019 were selected as the research objects.The CT value,iodine concentration,water concentration and energy spectrum curve slope under different single energy levels were compared between SCLC group and sarcoidosis group.Results The single-energy CT values of 40-80 keV segments in the arterial phase of the SCLC group were significantly higher than those in the sarcoidosis group(all P0.05).The single-energy CT values of 90-140 keV segments were not significantly different from those in the sarcoidosis group(all P0.05).The single-energy CT values of 40-90 keV segments in venous phase of the SCLC group were significantly higher than those of the sarcoidosis group(all P0.05),and the single-energy CT values of 100-140 keV segments were not significantly different from those of the sarcoidosis group(all P0.05).The concentrations of iodine in the arterial phase and venous phase of the SCLC group were(11.56±4.06)μg/cm

Objective To analyze the correlation between tortuosity and stenosis in patients with myocardial bridge(MB)on the left anterior descending artery(LAD). Methods Data of patients with MB on the LAD,which was discovered by coronary computed tomography angiography(CCTA),in the Affiliated Hospital of North China University of Science and Technology from October 2015 to December 2018 were retrospectively analyzed.Among them 278 patients with tortuosity on LAD and 278 patients without tortuosity were selected.The clinical charateristics(age,gender,hypertension,hyperlipidemia,diabetes,smoking history,and family history)as well as the incidence and severity of stenosis of LAD were recorded and compared. Results The incidence of coronary artery stenosis in the non-tortuosity group(57.6%)was significantly lower than that in the tortuosity group(71.9%)($\bar{χ}$=12.608

Since human coronavirus (HCoVs) was first described in the 1960s, seven strains of respiratory human coronaviruses have emerged and caused human infections. After the emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), a pneumonia outbreak of coronavirus disease 2019 (COVID-19) caused by a novel coronavirus (SARS-CoV-2) has represented a pandemic threat to global public health in the 21st century. Without effectively prophylactic and therapeutic strategies including vaccines and antiviral drugs, these three coronaviruses have caused severe respiratory syndrome and high case-fatality rates around the world. In this review, we detail the emergence event, origin and reservoirs of all HCoVs, compare the differences with regard to structure and receptor usage, and summarize therapeutic strategies for COVID-19 that cause severe pneumonia and global pandemic.

Objective To evaluate the potential correlation between coronary artery tortuosity caused by myocardial bridge and coronary atherosclerosis. Methods The data of 88 patients with suspected coronary heart disease in the Affiliated Hospital of North China University of Science and Technology during the period from March 2015 to June 2016 were retrospectively analyzed.Coronary artery tortuosity caused by myocardial bridge was diagnozed by computed tomography coronary angiography.Meanwhile,the contemporary data of patients diagnosed with coronary artery tortuosity without myocardial bridge were selected as the control group.The coronary atherosclerosis as well as coronary artery stenosis were observed,and clinical data including age,gender,hypertension,hyperlipidemia,diabetes,smoking history,family history,and body mass index(BMI) were collected and compared.The incidence of coronary atherosclerosis in terms of whole coronary artery,anterior segment of tortuosity,tortuosity segment,and posterior segment of tortuosity was compared firstly,followed by the comparisons of the differences in coronary artery stenosis degree in terms of anterior segment of tortuosity,tortuosity segment,and posterior segment of tortuosity.Finally,the differences of the incidence of coronary atherosclerosis in the complete MB group,incomplete MB group,and non-MB group with different degrees of tortuosity were compared.Results The incidences of coronary atherosclerosis on whole coronary artery(χ

Objective To study the impact of myocardial bridge (MB)-mural coronary artery (MCA) on myocardial functions.Methods Totally 82 patients presenting with chest tightness and chest pain who were diagnosed with the MB in the left anterior descending artery by CT coronary angiography were enrolled as the MB group,in which the thickness and length of MB and the systolic stenosis degree of MCA were measured.In addition,82 healthy subjects,as confirmed by health check-up,were set as the control group.The age,gender,body mass index (BMI),heart rate (HR),smoking history,interventricular septal thickness,left ventricular posterior wall thickness,diameter of left atrium,left ventricular end-diastolic diameter,left ventricular end-systolic diameter,left ventricular ejection fraction,and the cases of E'/A'1 were compared between MB group and control group.The potential correlations among the thicken/length of MB,the systolic stenosis degree of MCA and early diastolic peak strain rate(SRe)/late diastolic peak strain rate(SRa) were analyzed.Results The age (t=0.97,P=0.65),gender (χ目的 评估心肌桥(MB)-壁冠状动脉(MCA)对心功能的影响。方法 以胸闷、胸痛症状就诊,经CT冠状动脉成像(CTCA)诊断为左前降支单发MB的82例患者为研究对象,测量MB厚度、长度,计算MCA收缩期狭窄率。同期选择CTCA 未见异常的82例健康体检者作为正常对照组。两组均行超声心动图检查。记录年龄、性别、体质量指数(BMI)、心率及吸烟史等临床资料,比较MB组与正常对照组上述临床资料及室间隔,左心室后壁厚度,左心房内径,左心室舒张末内径、收缩末内径,左心室射血分数,E’/A’1例数的差异。MB 厚度、长度、MCA收缩期狭窄率与左心室前壁中段舒张早期及晚期峰值应变率(SRe,SRa)行相关性分析。结果 两组受试者在年龄(t=0.97,P=0.65)、性别(χ

Objective To explore the impact of myocardial bridge-mural coronary artery (MB-MCA) on myocardial blood supply. Methods The imaging data of 74 patients with the isolate MB in the left anterior descending artery undergoing 256-slice CT coronary angiography and myocardial perfusion imaging (MPI) were retrospectively analyzed. The subjects were divided into incomplete and complete MB types. The length of MB and the systolic stenosis degree of MCA were measured.The type and length of MB and the systolic stenosis degree of MCA (according to Noble grade) were compared between the normal and abnormal MPI groups. The clinical characteristics including age, gender, body mass index, hypertension, dyslipidemia, diabetes mellitus, and smoking history were also reviewed. Results There were 38 incomplete MB cases and 13 complete MB cases in the normal MPI group,and 5 and 18 in the abnormal MPI group (χ

Nowadays, there have been many data which are represented by tensor, that how to deal with these tensor data directly remains a significant challenge. In this paper, we propose a new tensor distance (TD) based least square twin support tensor machine (called TDLS-TSTM). Unlike the traditional Euclidean distance, TD considers the relationship information of various coordinates. TDLS-TSTM works directly on tensor data and aims to find two nonparallel hyperplanes for classification based on TD which can make full of structural information of data, solves two systems of linear equations rather than two quadratic programming problems. Compared with other classifiers, our method has the advantages of higher precision and accepted time consumption. The numerical experiments show the valid and efficient of TDLS-TSTM.

The aim of this study was to investigate the protective effect of simvastatin against radiation-induced tissue injury in mice. Mice were radiated with 4 Gy or 8 Gy after 20 mg/kg/d simvastatin treatment over 2 weeks. Morphological changes were observed in the jejunum and bone marrow, and apoptotic cells were determined in both tissues. Peripheral blood cells were counted, and the superoxide dismutase (SOD) activity and the malondialdehyde (MDA) level in tissues of both thymus and spleen were measured. Compared with the radiation-only group, 20 mg/kg/d simvastatin administration significantly increased the mean villi height and decreased apoptotic cells in jejunum tissue, and stimulated regeneration and reduced apoptotic cells in bone marrow. Peripheral blood cell analysis revealed that simvastatin treatment induced a larger number of red blood cells and increased the hemoglobin level present after 4 Gy of radiation. Interestingly, it was also found that the number of peripheral endothelial progenitor cells was markedly increased following simvastatin administration. Antioxidant determination for tissues displayed that simvastatin therapy increased the SOD activity after both 4 and 8 Gy of radiation, but only decreased the MDA level after 4 Gy. Simvastatin ameliorated radiation-induced tissue damage in mice. The radioprotective effect of simvastatin was possibly related to inhibition of apoptosis and improvement of oxygen-carrying and antioxidant activities.

Radiation-induced gastrointestinal syndrome occurs when the body is exposed to a high dose of radiation. Currently, safe and effective radioprotectants are not available. Apoptosis was reported to play a primary role in radiation-induced injury. Recent evidence suggests that stimulation of α7 nicotinic acetylcholine receptor (α7nAChR) prevents cell death by inhibition of apoptosis. In this study, we demonstrated that a single dose of PNU282987 (100 μg/kg, i.p.), a selective α7nAChR agonist, protected mice from intestinal injury and significantly improved survival when administered prior to lethal 8 Gy total body irradiation. In vitro, PNU282987 protected against 8 Gy radiation-induced cell death in human umbilical venous endothelial cells by inhibiting apoptosis. We conclude that activation of α7nAChR may provide a new therapeutic pathway for the treatment of radiation-induced damage and mortality.