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Large scale, high yield SiC/SiOx nanocables have been synthesized by thermal evaporation of carbon powders and silicon powders in the presence of Fe3O4 nanoparticle catalysts. Transmission electron microscopy and high-resolution transmission electron microscopy show that the nanocables consist of a 50–300 nm single-crystalline β-SiC core wrapped with a 10–20 nm amorphous SiOx shell. The nanocables have two broad photoluminescence peaks located around 390 and 460 nm when the 250 nm ultraviolet fluorescent light excitation is applied at room temperature. The results of field emission measurement of SiC/SiOx nanocables indicate the low turn-on and threshold electric fields of 3.2 and 5.3 V/μm at the vacuum gap of 200 μm, respectively. When the vacuum gap was increased to 1000 μm, the turn-on and threshold electric fields were decreased to 1.1 and 2.3 V/μm, respectively. The SiC/SiOx nanocables with good photoluminescence and field emission properties are promising candidates for ultraviolet-blue emitting devices, flat panel displays, and semiconductor field emitters. [ABSTRACT FROM AUTHOR]

Benzene is an important industrial chemical. It is also an environmental pollutant recognized as a human carcinogen. Both prenatal and adult exposures to benzene are associated with the development of leukemia. To understand the mechanism of benzene-induced epigenetic variations, we investigated the expression and methylation patterns of CpG (phosphodiester bond between cytosine and guanine) islands in p15 and p16 promoter regions in 1,4-benzoquinone (1,4-BQ)-treated primary cultivated C57BL/6J mouse bone marrow cells in vitro. The cell toxicity of 1,4-BQ was evaluated by cell viability test, real-time PCR was used to measure the mRNA expression levels, and bisulfite sequencing PCR (BSP) was used to look into the methylation patterns. The cell viability test indicates that 1,4-BQ exhibited a dose-dependent toxicity to mouse bone marrow cells. After a 24-h exposure to 1,4-BQ at final concentrations of 0, 0.1, 1, and 10 μmol/L, the mRNA expression of p15 and p16 decreased with the increase in 1,4-BQ concentration. The BSP results gathered from the exposure and the control groups were the same. In summary, despite the observation that short-term exposure to 1,4-BQ primary cultivated mouse bone marrow cells decreased the p15 and p16 transcripts, with no influence by their gene promoter methylation. [ABSTRACT FROM AUTHOR]

In this study, creep rupture in a bundle of slowly relaxing fibres was investigated. The intact fibre was assumed to exhibit linear elastic behaviour; however, its load did not drop to zero instantaneously after breaking but underwent a slow relaxation process, and thus, it introduced a time-dependent behaviour in the system, which was modelled by a Kelvin–Voigt element. Under the assumption of global load sharing for the redistribution of load, the analytical and simulated results showed the formation of two distinct regimes of the creep process depending on the value of the external load. For external loads greater than the critical load, the system suffered a macroscopic rupture in a finite time. However, for external loads smaller than the critical load, the system was characterized by an infinite lifetime. The critical load depended on the ratio of the elastic modulus between the intact and the failure elements, Eb/E. It was observed that the time to rupture, tf, had a power-law divergence with an exponent −1/2 when the load approached the critical load from above. Moreover, the acoustic emission response was measured from the rate of breaking of fibres in the simulations. [ABSTRACT FROM AUTHOR]

Objective: To explore the differences of risk stratification of very high-risk or extreme high-risk atherosclerotic cardiovascular diseases (ASCVD) and the attainment rates of low-density lipoprotein cholesterol (LDL-C) management targets evaluated by three different criteria, and the causal attributions of these differences. Methods: Patients with ASCVD were consecutively enrolled from January 1 to December 31 in 2019, and were evaluated for very high-risk or extreme high-risk and LDL-C goal attainment rates with 2018 American guideline on the management of blood cholesterol (2018AG), 2019 China Cholesterol Education Program (CCEP) Expert Advice for the management of dyslipidemias (2019EA) and 2020 Chinese expert consensus on lipid management of very high-risk ASCVD patients(2020EC), respectively. The causal attributions of the differences in attainment rates were analyzed as well. Results: A total of 1 864 ASCVD patients were included in this study. According to 2018AG, 2019EA and 2020EC, the proportions of the patients with very high-risk or extreme high-risk were 59.4%, 90.7%, and 65.6%, respectively. The absolute LDL-C target attainment rates were 37.2%, 15.7%, and 13.7%, respectively, the differences between each two rates were statistically significant (all P <0.001). As to the differences in attainment rates between 2020EC and 2018AG, 61.5% were due to the different LDL-C goal attainment values and 38.5% were caused by the different risk stratifications, while for the differences between 2020EC and 2019EA attainment rates, different LDL-C goal attainment values were responsible for 13.2%, and different risk stratifications were responsible for 86.8% of the differences. Conclusions: There are significant differences in the proportions and LDL-C attainment rates among the three different criteria for very high-risk or extreme high-risk ASCVD. 2020EC showed a moderate proportion of patients with extreme high-risk, and had the lowest LDL-C attainment rate. The differences between 2020EC and 2018AG are mainly due to the LDL-C target values, and the differences between 2020EC and 2019EA are mainly caused by the risk stratifications.

Objective: To explore the clinical value of quantitatively assessment of left ventricular strain in patients with coronary chronic total occlusion (CTO) by cardiac magnetic resonance imaging (CMR)-feature tracking (CMR-FT) technique. Methods: In this retrospective and observation study, patients with single CTO, who underwent CMR examination in Beijing Anzhen Hospital from November 2014 to January 2019, were selected as case group (CTO group), and those without cardiovascular diseases defined by echocardiography, electrocardiogram (ECG) and clinical history and with normal CMR results were selected as healthy control group (control group). General clinical data including age, gender, discharge diagnosis, and the examination results of echocardiography and ECG were obtained from the electronic medical record system. Two-dimensional CMR-FT was applied to measure left ventricle (LV) global peak radial, circumferential, and longitudinal strains (GPRS, GPCS and GPLS, respectively), and the regional myocardial strain in the target vessel area of CTO was analyzed. Grayscale thresholds of 5 standard deviations (SDs) were used to quantify late gadolinium enhancement (LGE). Patients with CTOs were divided into infract size>10% group and infarct size≤10% group, and left ventricular ejection fraction (LVEF)≥50% group and LVEF<50% group, respectively. The differences between various groups were compared. Results: There were 52 patients in CTO group (34 males, age (54.1±11.7) years, body mass index (BMI) (26.2±2.5)kg/m 2 ) and 30 patients in control group (14 males, age(51.6±12.3)years, BMI (25.6±3.3)kg/m 2 ). There was no significant difference in age, gender, and BMI between the two groups (all P >0.05). LVEF, GPRS, GPCS and GPLS were significantly lower in CTO group than in control group (all P <0.05), left ventricular volume (LVEDV) was similar between the two groups ( P >0.05). Among the patients with CTO, there were 26 patients with infarct size>10% and 26 patients with infarct size≤10%. GPRS, GPCS and GPLS were significantly lower (all P <0.05), while LVEF and LVEDV were similar in CTO patients with infarct size≤10% as compared to control group (both P >0.05). LVEF, GPRS, GPCS and GPLS were significantly lower (all P <0.05), while LVEDV was similar in CTO patients with infarct size>10% ( P >0.05) as compared to control group. GPRS and GPCS were significantly lower (both P <0.05), while LVEF, LVEDV and GPLS were similar in CTO patients with infarct size>10% as compared to infarct size≤10% group. There were 40 subjects in LVEF≥50% group and 12 subjects in LVEF<50% group. Compared with the control group, GPCS and GPLS of CTO patients were significantly lower in LVEF≥50% group and LVEF<50% group (all P <0.01), LVEF and LVEDV was similar in CTO patients with LVEF≥50% (both P >0.05), but LVEF was lower and LVEDV was larger in LVEF<50% group (both P <0.05). The GPRS, GPCS, GPLS and LVEF of CTO patients in LVEF ≥ 50% group were higher than those in LVEF<50% group (all P <0.0l), and the myocardial infarction size was smaller than that in LVEF reduced group ( P <0.0l), but there was no significant difference in LVEDV between the two groups ( P =0.07). In the CTO group, there were 21 patients with left anterior descending artery (LAD) occlusion and 126 segments supplied by the target vessels. The peak radial strain (PRS), circumferential strain (PCS) and longitudinal strain (PLS) in the blood supply area were lower than those in the control group (all P <0 01). In 7 patients with left circumflex artery (LCX) occlusion, the number of myocardial segments supplied by the target vessels was 35, and the PRS, PCS and PLS in the target vessel supply area were lower than those in the control group (all P <0 05). In 24 patients with right coronary artery (RCA) occlusion, the number of myocardial segments supplied by the target vessels was 120, and the PRS, PCS and PLS in the target vessel supply area were lower than those in the control group (all P <0.01). Among the 126 segments in 21 patients with LAD CTO, 91 (72.2%) segments had infarct size≤25%, 17 (13.5%) segments had infarct size between 26%-50%, 11 segments (8.7%) had infarct size between 51%-75%, and 7 (5.6%) segments had infarct size between 76%-100%. Among the 35 segments in 7 patients with LCX CTO, 31 (88.6%) segments had infarct size≤25%, and 4 (11.4%) segments had infarct size between 26%-75%. Among the 120 segments in 24 patients with RCA CTO, 96 (80.0%) segments had infarct size≤25%, 11 (9.2%) segments had infarct size between 26%-50%, 8 (6.7%) segments had infarct size between 51%-75%, and 5 segments (4.2%) had infarct size between 76%-100%. Conclusions: In this study with single CTO, although the LVEF is preserved in the majority of the patients, the left ventricular global and regional strain values are significantly decreased. The larger the infarct size, the greater the impact on radial and circumferential motion, reflecting the early impairment of left ventricular function in these patients.

We have successfully synthesized large-scale crystalline boron nanowire bundles (BNBs) by chemical vapor deposition method. Fe(3)O(4) nanoparticles were used as catalysts spreading on ceramic substrate during the reaction process. The bundles consisted of many thin boron nanowires with a mean diameter of about 25nm and a length of several micrometers. In addition, boron nanowires are single crystals with an alpha-tetragonal structure and grow along [001] orientation. These nanowires have a surface electron affinity of 3.76eV and a work function of 4.54eV. A turn-on field of 5.1V/mum and a threshold field of 10.5V/mum were found in the nanowire bundles, and stable field emission was recorded at the same time.

Objective: To investigate the effects of a modified SD therapy (intravenous high dose hydrocortisone and low molecular dextran) on Bell's palsy(BP), and to avoid the severe side-effects such as hepatic and renal disorders during the treatment., Method: Seventy-one BP patients were treated with modified SD method (modified group), thirty-two BP patients took prednisone (control group), and the curative rates of two therapies were compared, in the meanwhile recorded the side effects in detail., Result: Curative rate in modified group was 95.8% (House-Brakmsnn I-II) and in control group was 81.2% (P < 0.05). In modified group, the curative rate (I grade) in the patients were treated within 24 hours following onset was 75.0%, and the curative rate in other three subgroups were treated within 24-48 hours, 2-3 day and 3-5 day following onset was 43.8%, 26.7%, 18.8% respectively. Modified group had not shown hepatic and renal disorders or gastric ulcer., Conclusion: Modified SD method may increase recoverable rate and can avoid significant side effects for BP, and emphasizes the importance of the administration of SD therapy in the early stage of the disease.