Haemodynamic mechanism of formation and distribution of coronary atherosclerosis: A lesion-specific model

© IMechE 2020. Coronary arterial disease, as the most devastated cardiovascular disease, is caused by the atherosclerosis in the coronary arteries, which blocks the blood flow to the heart, resulting in the deficient supply of oxygen and nutrition to the heart, and eventually leading to heart failure. To date, haemodynamic mechanisms for atherosclerosis development are not fully understood although it is believed that the haemodynamic disturbance at the region of the arterial bifurcation, particular, bifurcation angle, plays an important role in the atherosclerosis development. In this study, two types of computational fluid dynamics models, lesion-specific and idealized models, combined with the computer tomography imaging techniques, are used to explore the mechanism of formation and distribution of the atherosclerosis around the bifurcation of left coronary artery and its association with the bifurcation angle. The lesion-specific model is used to characterize the effect of personalized features on the haemodynamic performance, while the idealized model is focusing on the effect of single factor, bifurcation angle, on the haemodynamic performance. The simulated results from both types of the models, combined with the clinical observation, revealed that the three key areas around the bifurcations are prone to formation of the atherosclerosis. Unlike the idealized models, lesion-specific modelling results did not show the significant correlation between the wall shear stress and bifurcation angle, although the mean value of the wall shear stress in smaller bifurcation angles (less than 90°) is higher than that with larger bifurcation angles (greater than 90°). In conclusion, lesion-specific computational fluid dynamics modelling is an efficient and convenient way to predict the haemodynamic performance around the bifurcation region, allowing the comprehensive information for the clinicians to predict the atherosclerosis development. The idealized models, which only focus on single parameter, may not provide the sufficient and reliable information for the clinical application. A novel multi-parameters modelling technique, therefore, is suggested to be developed in future, allowing the effects of many parameters on the haemodynamic performance to be evaluated

RETRATO SIN IDENTIFICAR [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte, 201

Powder Technol.

Illite/TiO2 composite pigments were prepared through hydrolysis of titanium sulfate on the surface of illite particles. Some factors that influence the coating process of TiO2 were investigated in single-factor tests, and the whiteness and oil absorption value of coating products were tested. With optimized coating conditions, the whiteness and oil absorption of illite/TiO2 composite pigments can reach to 95.73% and 31.35 g/100 g, respectively. The crystalline phases and surface morphology of the coating products were characterized by X-ray diffraction and scanning electron microscopy. In addition, the precipitated mechanism of anatase was investigated by X-ray photoelectron spectroscopy. The results showed that the microstructure of TiO2 coating on illite substrate was mainly anatase. The uniform and dense TiO2 layers were anchored to the surface of illite by forming Ti-O-Si bond. (C) 2014 Elsevier B.V. All rights reserved.Illite/TiO2 composite pigments were prepared through hydrolysis of titanium sulfate on the surface of illite particles. Some factors that influence the coating process of TiO2 were investigated in single-factor tests, and the whiteness and oil absorption value of coating products were tested. With optimized coating conditions, the whiteness and oil absorption of illite/TiO2 composite pigments can reach to 95.73% and 31.35 g/100 g, respectively. The crystalline phases and surface morphology of the coating products were characterized by X-ray diffraction and scanning electron microscopy. In addition, the precipitated mechanism of anatase was investigated by X-ray photoelectron spectroscopy. The results showed that the microstructure of TiO2 coating on illite substrate was mainly anatase. The uniform and dense TiO2 layers were anchored to the surface of illite by forming Ti-O-Si bond. (C) 2014 Elsevier B.V. All rights reserved

A Simple Method for Solving the Power Fluctuation Issue of a Base Station’s Surrounding Areas Based on Half Tyler Distribution

This paper proposes array antennas based on half Tyler (HT) distribution that can realize omnidirectional null-free (ONF) beams. Array 1 employs the usual edge feeding approach, working at 3.5 GHz with a bandwidth of 0.25 GHz, whereas array 2 operates at 26 GHz with a bandwidth of 3 GHz. We evaluated the far-field performance of linear arrays consisting of 6, 8, 12, and 16 elements. The simulation and measurement results show that the proposed HT approach can achieve a near-ONF pattern and cover a broad area of ±42° on an eight-element linear array. The ONF beam reduces community power fluctuations and increases power by 20 dBm in surrounding areas of the base station (BS). The fluctuation treatment effect can be influenced by adjusting the weighting of sidelobe depression (dp): compared to the uniformly excited one, for example, the maximum ONF gain of an eight-element linear operating at 3.5 GHz is only reduced by 0.5 dB when dp = −30 and by 1–2 dB when dp = −60

Prospective association between perceived stress and anxiety among nursing college students: the moderating roles of career adaptability and professional commitment

Abstract Background Anxiety may stay with nursing students throughout their internship and even persist afterwards. Although many studies have explored the effects of perceived stress on anxiety, the relationship between pre-internship perceived stress and post-internship anxiety levels has not been clarified. In addition, none had focused on the moderating roles of career adaptability and professional commitment between perceived stress and anxiety. This study aims to investigate the influence of pre-internship perceived stress on the post-internship anxiety level of nursing college students, and to analyze the moderating effects of career adaptability and professional commitment on their relationships. Methods A longitudinal study design was employed. Full-time nursing college students from a Chinese medical university were recruited by convenient sampling. All surveys were conducted via Wen Juan Xing ( www.wjx.cn ), a widely used web-based survey platform in China. Two waves of surveys were collected in the pre-internship and post-internship periods, with an interval of one year. Among 823 nursing students recruited, 692 students completed all two waves of the survey (response rate: 84.08%). Participants completed a series of questionnaires examining general demographic characteristics, perceived stress, anxiety, career adaptability, and professional commitment both before and after the internship. The bias-corrected bootstrap technique of the Hayes PROCESS macro (Model 2) was used to test the moderation effect. Results Pre-internship perceived stress was positively associated with post-internship anxiety (β = 0.474, p < 0.001). Career adaptability would mitigate the effect of perceived stress on anxiety (β = -0.009, p < 0.01, 95% CI = [-0.013, -0.004]), and this influence became stronger for nursing college students with higher levels of career adaptability. Instead, the professional commitment would enhance the effect of perceived stress on anxiety (β = 0.004, p < 0.05, 95% CI = [0.001, 0.009]). Conclusions Adequate career adaptability was key to alleviating anxiety among nursing interns. Nursing educators and clinical nursing managers should pay attention to cultivating the career adaptability of nursing college students in order to help them successfully achieve identity transformation and career development. Meanwhile, it is crucial to guide them to develop appropriate professional commitment

The prognostic value of radiological and pathological lymph node status in patients with cervical cancer who underwent neoadjuvant chemotherapy and followed hysterectomy

Abstract To investigate the prognostic value of lymph node status in patients with cervical cancer (CC) patients who underwent neoadjuvant chemotherapy (NACT) and followed hysterectomy. Patients in two referral centers were retrospectively analyzed. The baseline tumor size and radiological lymph node status (LNr) were evaluated on pre-NACT MRI. Tumor histology, differentiation and pathological lymph node status (LNp) were obtained from post-operative specimen. The log-rank test was used to compare survival between patient groups. Cox proportional hazards regression models were employed to estimate the hazard ratio (HR) of various factors with progression-free survival (PFS) and overall survival (OS). A total of 266 patients were included. Patients with 2018 FIGO IIIC showed worse PFS compared to those with FIGO IB-IIB (p < 0.001). The response rate in patients with LNp(−) was 64.1% (134/209), significantly higher than that of 45.6% (26/57) in patients with LNp( +) (p = 0.011). Multivariate Cox analysis identified the main independent predictors of PFS as LNp( +) (HR = 3.777; 95% CI 1.715–8.319), non-SCC (HR = 2.956; 95% CI 1.297–6.736), poor differentiation (HR = 2.370; 95% CI 1.130–4.970) and adjuvant radiation (HR = 3.266; 95% CI 1.183–9.019). The interaction between LNr and LNp regarding PFS were significant both for univariate and multivariate (P = 0.000171 and 1.5357e−7 respectively). In patients with LNr( +), a significant difference in PFS was observed between patients with LNp(−) and LNp( +) (p = 0.0027). CC patients with FIGO 2018 stage IIIC who underwent NACT and followed hysterectomy had worse PFS compared to those with IB-IIB. LNp( +), non-SCC, poor differentiation and adjuvant radiation were independent risk factors for PFS. The adverse prognostic value of LNp( +) was more significant in patients with LNr( +)

Template-Assisted Synthesis of Nickel Sulfide Nanowires: Tuning the Compositions for Supercapacitors with Improved Electrochemical Stability

Ni nanowires were first synthesized via a chemical method without surfactants or a magnetic field. A series of nickel sulfide nanowires (Ni₃S₂–Ni, Ni₃S₂–NiS–Ni, and Ni₃S₂–NiS) have been successfully prepared by a controlled sacrificial template route based on the conductive Ni nanowire template. Electrochemical characterizations indicate that Ni₃S₂–NiS nanowires present superior redox reactivity with a high specific capacitance of 1077.3 F g^–1 at 5 A g^–1. Besides, its specific capacitance can remain about 76.3% after 10 000 cycles at 20 A g^–1. On the contrary, the nickel-preserving sulfide nanowires (Ni₃S₂–Ni and Ni₃S₂–NiS–Ni) deliver enhanced cycling stability as 100% of the initial specific capacitance of Ni₃S₂–Ni is retained after 10 000 cycles. The outstanding electrochemical stability can be attributed to the interaction between nickel sulfides and the conductive nickel nanowires

Template Synthesis of Shape-Tailorable NiS₂ Hollow Prisms as High-Performance Supercapacitor Materials

Uniform NiS₂ hollow nanoprisms have been controllably synthesized by a facial sacrificial template method including two-step refluxed reactions. The morphology of the hollow NiS₂ prisms can be easily tailored by the low cost nickel complex template. With unique hollow structure, efficient electron, and ion transport pathway as well as single crystal structure, the NiS₂ hollow prisms electrode exhibits excellent pseudocapacitive performance in LiOH electrolyte. It can deliver a specific capacitance of 1725 F g^–1 at a current density of 5 A g^–1 and 1193 F g^–1 even at a current density of 40 A g^–1. Furthermore, the materials also present an amazing cycling stability, that is, the specific capacitance can increase from 1367 F g^–1 to 1680 F g^–1 after 10 000 cycles of charge–discharge at the current density of 20 A g^–1

Palladium-Catalyzed, Ligand-Free Suzuki Reaction in Water Using Aryl Fluorosulfates

Aryl fluorosulfates were prepared by a simple method and employed as coupling partners in the Suzuki–Miyaura reaction. The cross-coupling reactions were performed in water under air at room temperature without ligands or additives such as surfactants or phase-transfer reagents and proceeded smoothly to give excellent yields. Aryl fluorosulfates could also be used as alternatives to halides or triflates in other coupling reactions