Magnetic Resonance Image Texture Analysis of the Periaqueductal Gray Matter in Episodic Migraine Patients without T2-Visible Lesions

Zhiye Chen,Xiaoyan Chen,Mengqi Liu,Shuangfeng Liu,Shengyuan Yu,Lin Ma 대한영상의학회 2018 Korean Journal of Radiology Vol.19 No.1

Objective: The periaqueductal gray matter (PAG), a small midbrain structure, presents dysfunction in migraine. However, the precise neurological mechanism is still not well understood. Herein, the aim of this study was to investigate the texture characteristics of altered PAG in episodic migraine (EM) patients based on high resolution brain structural magnetic resonance (MR) images. Materials and Methods: The brain structural MR images were obtained from 18 normal controls (NC), 18 EM patients and 16 chronic migraine (CM) patients using a 3T MR system. A PAG template was created using the International Consortium Brain Mapping 152 gray matter model, and the individual PAG segment was developed by applying the deformation field from the structural image segment to the PAG template. A grey level co-occurrence matrix was used to calculate the texture parameters including the angular second moment (ASM), contrast, correlation, inverse difference moment (IDM) and entropy. Results: There was a significant difference for ASM, IDM and entropy in the EM group (998.629 ± 0.162 x 10-3, 999.311 ± 0.073 x 10-3, 916.354 ± 0.947 x 10-5) compared to that found in the NC group (998.760 ± 0.110 x 10-3, 999.358 ± 0.037 x 10-3 and 841.198 ± 0.575 x 10-5) (p < 0.05). The entropy was significantly lower among the patients with CM (864.116 ± 0.571 x 10-5) than that found among patients with EM (p < 0.05). The area under the receiver operating characteristic curve was 0.776 and 0.750 for ASM and entropy in the distinction of the EM from NC groups, respectively. ASM was negatively related to disease duration (DD) and the Migraine Disability Assessment Scale (MIDAS) scores in the EM group, and entropy was positively related to DD and MIDAS in the EM group (p < 0.05). Conclusion: The present study identified altered MR image texture characteristics of the PAG in EM. The identified texture characteristics could be considered as imaging biomarkers for EM.

Comparison of the effect of oral megestrol acetate with or without levonorgestrel-intrauterine system on fertility-preserving treatment in patients with early-stage endometrial cancer: a prospective, open-label, randomized controlled phase II trial (Clin

Zhiying Xu,Bingyi Yang,Jun Guan,Weiwei Shan,Jiongbo Liao,Wenyu Shao,Xiaojun Chen 대한부인종양학회 2023 Journal of Gynecologic Oncology Vol.34 No.1

Objective: To evaluate the effect of levonorgestrel-releasing intrauterine system (LNG-IUS) plus oral megestrol acetate (MA) as fertility-preserving treatment in patients with early-stage endometrial cancer (EEC). Methods: In this single-center, phase II study with open-label, randomized and controlled design, young patients (18–45 years) diagnosed with primary EEC were screened, who strongly required fertility-preserving treatment. Patients were randomly assigned (1:1) into MA group (160 mg oral daily) or MA (160 mg oral daily) plus LNG-IUS group. Pathologic evaluation on endometrium retrieved by hysteroscopy was performed every 3 months. The primary endpoint was complete response (CR) rate within 16 weeks of treatment. The secondary endpoints were CR rate within 32 weeks of treatment, adverse events, recurrent and pregnancy rate. Results: Between July 2017 and June 2020, 63 patients were enrolled and randomly assigned. Totally 56 patients (26 in MA group; 28 in MA + LNG-IUS group) were included into primary-endpoint analyses. The median follow-up was 31.6 months (range, 3.1–94.0). No significant difference in 16-week CR rate were found between MA and MA + LNG-IUS groups (19.2% vs. 25.0%, p=0.610; odds ratio=1.40; 95% confidence interval=0.38–5.12), while the 32-week CR rates were also similar (57.1% and 61.5%, p=0.743), accordingly. More women in MA + LNG-IUS group experienced vaginal hemorrhage (46.4% vs. 16.1%; p=0.012) compared with MA group. No intergroup difference was found regarding recurrence or pregnancy rate. Conclusion: Compared with MA alone, the addition of LNG-IUS may not improve the early CR rate for EEC, and may produce more adverse events instead.

Characteristics of progestin- insensitive early stage endometrial cancer and atypical hyperplasia patients receiving second-line fertility-sparing treatment

Shuang Zhou,Zhiying Xu,Bingyi Yang,Jun Guan,Weiwei Shan,Yue Shi,Xiaojun Chen 대한부인종양학회 2021 Journal of Gynecologic Oncology Vol.32 No.4

Objective: This study investigated the characteristics of progestin-insensitive endometrioid endometrial cancer (EEC) and atypical endometrial hyperplasia (AEH) patients receiving fertility-sparing treatments and assessed the therapeutic effects of second-line fertility- preserving treatments. Methods: Three hundred and thirty-eight patients with EEC (n=75) or AEH (n=263) receiving fertility-preserving treatment were retrospectively analyzed. ‘Progestin-insensitive’ was defined as meeting one of the following criteria: 1) presented with progressed disease at any time during conservative treatment, 2) remained with stable disease after 7 months of treatment, and/or 3) did not achieve complete response (CR) after 10 months of treatment. Clinical characteristics and treatment results of progestin-insensitive patients receiving second-line treatment and those of progestin-sensitive patients were compared. Results: Eight-two patients (59 AEH and 23 EEC) were defined as progestin-insensitive and 256 as progestin-sensitive. In multivariate analysis, body mass index ≥28.0 kg/m2 (odds ratio [OR]=1.898) and lesion size >2 cm (OR=2.077) were independent predictors of progestin- insensitive status. Compared to AEH patients, progestin-insensitive EEC patients had poorer second-line treatment responses (28-week cumulative CR rate after changing second-line treatment, 56.3% vs. 85.4%, p=0.011). No statistical difference was found in CR rate among different second-line treatments. Conclusion: Obesity and larger lesion size were independent risk factors associatedwith progestin-insensitive status. In progestin-insensitive patients receiving second-line treatment, EEC patients had lower CR rate comparing with AEH patients. Further study with larger sample size is needed to evaluate efficacy of different second-line treatments for progestin insensitive patients.

Numerical investigation of the influence of structures in bogie area on the wake of a high-speed train

Dongwei Wang,Chunjun Chen,Zhiying He 한국풍공학회 2022 Wind and Structures, An International Journal (WAS Vol.34 No.5

The flow around a high-speed train with three underbody structures in the bogie area is numerically investigated using the improved delayed detached eddy simulation method. The vortex structure, pressure distribution, flow field structure, and unsteady velocity of the wake are analyzed by vortex identification criteria Q, frequency spectral analysis, empirical mode decomposition (EMD), and Hilbert spectral analysis. The results show that the structures of the bogie and its installation cabin reduce the momentum of fluid near the tail car, thus it is easy to induce flow separation and make the fluid no longer adhere to the side surface of the train, then forming vortices. Under the action of the vortices on the side of the tail car, the wake vortices have a trend of spanwise motion. But the deflector structure can prevent the separation on the side of the tail car. Besides, the bogie fairings do not affect the formation process and mechanism of the wake vortices, but the fairings prevent the low-speed fluid in the bogie installation cabin from flowing to the side of the train and reduce the number of the vortices in the wake region.

Effect of government R&D subsidies on firms’ innovation in China

Wu Ruirui,Liu Zhiying,Ma Chaoliang,Chen Xiafei 기술경영경제학회 2020 ASIAN JOURNAL OF TECHNOLOGY INNOVATION Vol.28 No.1

This study investigates the effects of R&D subsidies on firms’ innovation using panel data of Chinese listed firms from 2008 to 2013. Through propensity score matching method, we determine that recurrent, high-tech firms are more likely to receive public grants. Moreover, firms affiliated with higher-level governments and located in minimally marketised regions have a higher probability of receiving government financial support. China's state intervention to correct market failure related to firms’ R&D activity is confirmed to be reasonable in an observable time given an instantaneous additionality effect. However, the stimulation effect of R&D subsidies on innovation outputs has not been verified. Results obtained through a continuous matching method show no optimal amount of R&D subsidies for firms in China, but a declining yet a positive marginal effect of treatment has been identified given an increase in the amount of R&D subsidies.

A Dislocation Density Based Crystal Plasticity Model of 3D Complex Sheet Metal Forming

Haiming Zhang,Xianghuai Dong,Qian Wang,Zhiying Chen 한국소성가공학회 2011 기타자료 Vol.2011 No.8

A dislocation density based crystal plasticity model is used to simulate sheet metal forming processes under different temperature. In the present model, dislocation densities in each slip system are taken as internal state variables. An extended Kocks-Mecking-Estrin evolution law is adopted to describe the athermal storage, and the strain rate and temperature sensitive annihilation, of dislocation densities. The critical resolved stress on a specified slip system is related with dislocation densities in all slip systems, the corresponding mesoscopic coefficients of interaction between different slip systems are determined by recent dislocation dynamics simulations. On the basis of thermally activated dislocation motion, this physically based model is capable of describing the softening resulted from dynamic recovery. This model incorporated with a hyperelastic constitutive law is then implemented into an explicit finite element code, to make it deal with the strong nonlinear problems more efficiently. An iteration-free semi-implicit method, which is more suitable for explicit FEM, is adopted as the integration algorithm of the model. This model is used to investigate the deformation characteristics of warm forming of Al-Mg alloy under different temperatures. The simulation results show that the model is robust and efficient, has the potential to be used in the practical engineering simulation. It also confirms that the micromechaincs models can be used to simulate conventional sheet metal forming.