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Although the incidence of thyroid carcinoma has increased in recent years, follicular thyroid carcinoma with bone metastasis as the first symptom remains rare. Here, we report a case of occult follicular thyroid carcinoma in a 65-year-old female patient admitted to hospital with cerebrovascular disease. Computed tomography findings suggested a diagnosis of meningioma; however, magnetic resonance imaging results showed multiple skull bone destruction with soft tissue masses on the left side of the skull. After surgical resection, the pathology results revealed skull metastasis of follicular thyroid carcinoma. We present this case not only because of the diagnostic challenge it posed, but also because the patient had multiple skull metastases from follicular thyroid carcinoma.

Domestic and foreign relevant literatures of granular column collapse movement models are concluded to analyze the effects of initial spatial characteristics, essential physical properties of particles, boundaries, and environment conditions of model on the movement and accumulation characteristics of granular columns. Besides, the related mechanisms of movement and accumulation characteristics of granular columns are also analyzed. Remarkable linear and power relationships exist between the movement distance and the aspect ratios of initial height to initial width. Similarly, remarkable linear and power relationships exist between accumulation height and aspect ratio of initial height to initial width. The movement patterns and energy consumption mechanisms for granular columns with large aspect ratios are significantly different from those with small aspect ratios. A consensus has basically been reached concerning the effect of particle size, particle stiffness, particle breakage, and wet particles on the movement and accumulation characteristics of granular columns. Some preliminary research achievements of the effects of different wall constraints, fluidization phenomenon due to the gas mixing and water condition on the movement and accumulation characteristics of granular column are obtained. However, there still exist disagreements in the conclusions about the influences of initial porosity of granular column, particle friction, and wall friction on the movement and accumulation characteristics of granular column. A review of the current research indicate that the research in the future will be focused on the relationship between forces acted on particles and movement regimes. The mechanisms of the effect of complex particle shape, surface, particle density, and water movement conditions on the movement and accumulation characteristics of granular column collapse will also be focused on in the future.

Objective: The study investigated the accuracy of coronary artery calcium scores (CACS) and the potential for reducing radiation dose using non-gated low-dose non-contrast chest computed tomography (CT) scanning with tin filtration for one-stop screening of the lungs and heart. Methods: A prospective study was conducted,193 Patients received two scans for determining CACS, including an ECG-gated CT at 120 kV (ECG-gated CT), followed by a non-gated low-dose chest CT using 100 kV with tin filtration (non-gated Sn100 kV-LDCT). The Agatston score (AS), risk stratification, and radiation dose were compared between the scan types. Results: There was good consistency in the AS from both an ECG-gated CT and a non-gated low-dose chest CT scan, which had a high correlation (r = 0.970). The Kappa value of risk stratification of the two scan types was 0.549. The area under the ROC curve (AUC) of the CACS was used to develop a new risk stratification standard for non-gated Sn100 kV-LDCT evaluation of CACS. In comparison to the CACS measured by ECG-gated CT, non-gated Sn100 kV-LDCT had an AUC of 0.951 and an optimal critical value of 4.6 in the low-risk category. The AUC of low-medium risk was 0.966, and the optimal critical value was 41.2. The AUC of the medium-high risk category was 0.968, and the optimal critical value was 230. The consistency in CACS measured by ECG-gated CT and non-gated Sn100 kV-LDCT had a Kappa value of 0.831. The Effective dose (ED) of non-gated Sn100 kV-LDCT and ECG-gated CT was 0.056 ± 0.017 mSv and 0.685 ± 0.455 mSv, respectively (p

Since mechanical loads exert a significant influence on the life span of wind turbines, the reduction of transient load on drive-train shaft has received more attention when implementing a maximum power point tracking U+0028 MPPT U+0029 controller. Moreover, a trade-off between the efficiency of wind energy extraction and the load level of drive-train shaft becomes a key issue. However, for the existing control strategies based on nonlinear model of wind turbines, the MPPT efficiencies are improved at the cost of the intensive fluctuation of generator torque and significant increase of transient load on drive train shaft. Hence, in this paper, a nonlinear controller with variable parameter is proposed for improving MPPT efficiency and mitigating transient load on drive-train simultaneously. Then, simulations on FAST U+0028 Fatigue, Aerodynamics, Structures, and Turbulence U+0029 code and experiments on the wind turbine simulator U+0028 WTS U+0029 based test bench are presented to verify the efficiency improvement of the proposed control strategy with less cost of drive-train load.

This study focuses on the development of optimal torque (OT) control, which is a commonly used method for maximum power point tracking (MPPT). Due to the sluggish response of wind turbines with high inertia, conventional OT control was improved to increase MPPT efficiency by dynamically modifying the generator torque versus rotor speed curve. An idea that tracking a local interval of wind speed where the wind energy is primarily distributed rather than the total range of wind speed variation is applied in this study. On this basis, an effective tracking range (ETR) that corresponds to the local interval of wind speed with concentrated wind energy distribution is proposed and an improved OT control based on ETR is developed. In this method, based on a direct relationship between ETR and wind conditions, the torque curve can be quickly optimised so that higher and more stable MPPT efficiency can be achieved under varying wind conditions. Meanwhile, MPPT efficiency enhancement by reducing tracking range without increasing torque discrepancy leads to a low cost of generator torque fluctuation and drive train load. Finally, simulations based on fatigue, aerodynamics, structures, and turbulence (FAST) code and experiments conducted on a wind turbine simulator are presented to verify the proposed method.

While aging is associated with increased knowledge, it is also associated with decreased semantic integration. To investigate brain activation changes during semantic integration, a sample of forty-eight 25-75 year-old adults read sentences with high cloze (HC) and low cloze (LC) probability while functional magnetic resonance imaging was conducted. Significant age-related reduction of cloze effect (LC vs. HC) was found in several regions, especially the left middle frontal gyrus (MFG) and right inferior frontal gyrus (IFG), which play an important role in semantic integration. Moreover, when accounting for global gray matter volume reduction, the age-cloze correlation in the left MFG and right IFG was absent. The results suggest that brain structural atrophy may disrupt brain response in aging brains, which then show less brain engagement in semantic integration.

Due to the randomness and rapid fluctuation of turbulent wind, the effects of turbulence on maximum power point tracking (MPPT) of wind turbine should be focused on. Previous work was mainly concerned with two characteristics of turbulent wind, i.e. mean wind speed and turbulence intensity. It has been found that besides the aforementioned two factors, turbulence frequency is also included in the characteristics of turbulent wind. Confronting this characteristic of wind speed fluctuation which has not been fully considered, relevant researches merely analyzed the impact of the variation of turbulence frequency itself on MPPT. However, the variation of the extent of mean wind speed and turbulence intensity affecting MPPT resulted from different turbulence frequency, i.e. the indirect effect, is required to be further investigated. For this purpose, the relationship between wind speed frequency and the sensitivities of MPPT efficiency to mean wind speed and turbulence intensity are derived in this paper. Moreover, the mechanism of the indirect effects of wind speed frequency on MPPT is investigated by the time-domain simulations on the simplified model of wind turbine with periodic wind speed and the FAST model of NREL CART3 wind turbine with turbulence.

To analyze and compare the effectiveness of the closed reduction with elastic intramedullary nailing and open reduction with Kirschner wire fixations in the treatment of O'Brien type III radial neck fractures in children.Between November 2007 and November 2010, 31 children with O'Brien type III radial neck fractures were treated by the closed reduction with elastic intramedullary nailing fixation (closed reduction group, n=18) and by the open reduction with Kirschner wire fixation (open reduction group, n=13). There was no significant difference in age, gender, disease duration, and fracture classification between 2 groups (P0.05).The incisions of 2 groups healed primarily. All the patients were followed up 1-2 years (mean, 1.5 years). Limitation of the elbow extension occurred in 2 cases of the closed reduction group, limitations of the elbow extension, flexion, and forearm pronation in 6 cases of the open reduction group. There was no significant difference in elbow flexion, extension, pronation, and supination between affected side and normal side in the closed reduction group (P0.05). Except in supination (P0.05), there were significant differences in flexion, extension, and pronation between affected side and normal side in the open reduction group (P0.05). According to Metaizeau's grading criterion, excellent results were achieved in 16 cases and good in 2 cases in the closed reduction group; excellent results were achieved in 4 cases, good in 4 cases, fair in 3 cases, and poor in 2 case in the open reduction group; and there was significant difference between 2 groups (Z=3.435, P=0.001). The X-ray films showed anatomical reduction in 2 groups before removal of internal fixation; redisplacement occurred in 4 cases after removal of internal fixation in the open reduction group, no redisplacement occurred in the closed reduction group. There was no avascular necrosis of radial head and epiphyses during follow-up.Comparison with the open reduction with Kirschner wire fixation, the closed reduction with elastic intramedullary nailing fixation is a reliable and good treatment for O'Brien type III radial neck fractures in children, because it has the advantages of minimal invasion, easy operation, stable fixation, early mobilization, and less complication.