Hypermethylation of Frizzled1 is associated with Wnt/β-catenin signaling inactivation in mesenchymal stem cells of patients with steroid-associated osteonecrosis

Zhibo Sun,Jing Jiao,Feng Liu,Yue Yang,Shanfeng Zhang,Zhenhua Fang,Zhipeng Dai,Zhibo Sun 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

The Wnt/β-catenin signaling pathway is associated with the pathogenesis of steroid-induced osteonecrosis. Our investigation studied whether aberrant CpG island hypermethylation of the FZD1 gene was present in patients with osteonecrosis of the femoral head (ONFH), which results in Wnt/β-catenin signaling inactivation and subsequent cell dysfunction. Bone marrow was collected from the proximal femurs of patients with steroid-associated ONFH (n = 21) and patients with new femoral neck fractures (n = 22), and then mesenchymal stem cells (MSCs) were isolated. We investigated cell viability, the transcription and translation levels of Wnt/β-catenin signaling-related genes, the extent of methylation at CpG islands of the FZD1 promoter, and the osteogenic and adipogenic differentiation abilities of MSCs from the control group and from the ONFH group treated with or without 5′-Aza-dC. According to the results, MSCs from the ONFH group showed a reduced proliferation ability, low transcription and translation levels of FZD1, inhibition of the Wnt/β-catenin signaling pathway, weakened osteogenesis and enhanced adipogenesis ability. Aberrant CpG island hypermethylation of FZD1 was observed in the ONFH group. Treatment with 5’-Aza-dC resulted in de novo FZD1 expression, reactivation of the Wnt/β-catenin signaling pathway and promotion of osteogenesis. Taken together, our study not only provides novel insights into the regulation of the Wnt/β-catenin signaling pathway in this disease but also reveals potential for the use of demethylating agents for the treatment of GC-associated ONFH.

A pilot study of gonadotropin-releasing hormone agonist combined with aromatase inhibitor as fertility-sparing treatment in obese patients with endometrial cancer

Zhibo Zhang,Huifang Huang,Fengzhi Feng,Jinhui Wang,Ninghai Cheng 대한부인종양학회 2019 Journal of Gynecologic Oncology Vol.30 No.4

Objective: This study aims to evaluate the effects and pregnancy outcomes of gonadotropin-releasing hormone agonist (GnRH agonist) combined with aromatase inhibitor (AI) in preserving the fertility of obese women with grade 1 endometrial cancer (EC). Methods: This study recruited obese EC patients who wished to preserve their fertility. The treatment regimen consisted of intramuscular GnRH agonist 3.75 mg every 4 weeks and oral AI 2.5 mg daily. The maintenance regimen was the same as the initial treatment regimen. Primary outcomes included response rate, time to complete response (CR), and time to recurrence; pregnancy outcomes included the time to pregnancy, pregnancy rate and live birth rate. Results: Six obese patients with EC were included in this study, with the age (mean±standard deviation [SD]) of 30.5±3.3 years and body mass index (mean±SD) of 35.0±1.4 kg/m2. CR rate was 100%, and time to CR was 3–6 months. None of the patients had recurrence after a median follow-up of 4.0 years (range, 1.3–7.0 years). The most common side effects were menopause-like symptoms. Among these patients, no weight gain was observed during treatment. The pregnancy rate and live birth rate was 50.0% and 75.0%, respectively, with a median time to pregnancy of 2.4 years (range, 1.0–5.5 years). Conclusion: The combination of GnRH agonist and AI demonstrated promising long-term effect in young obese EC patients who wished to preserve their fertility. No weight gain side effects were observed. Further studies with a larger sample size are needed to fully evaluate this novel treatment regimen.

Temporal and spatial characteristics of coal-mine microseism based on single-link cluster

Zhibo Zhang,Enyuan Wang,Enyuan Wang 한국지질과학협의회 2017 Geosciences Journal Vol.21 No.2

Single-link cluster is introduced into mine microseism monitoring from a seismology point of view. The changes in spatial correlation length of mine microseismic events at different spatial scales are analyzed, and the underlying mechanisms are explained. The results show that large-energy microseismic events often occur after the spatial correlation length drops to a low value when the spatial scale is large. The larger the energy of microseismic events is, the more obvious the law is. Large-energy microseismic events occur after the spatial correlation length exhibits the power-law growth phenomenon, when the spatial scale becomes small. The smaller the spatial scale is, the more obvious the law is. The reason for this property is that microseismic events exhibit the space aggregation phenomenon before a large-energy microseismic event occurs, resulting in decreases in spatial correlation length when the spatial scale is large. By contrast, when the spatial scale is small, the spatial correlation degree of regional microseismic sources is high. Small-energy microseismic events occur gradually with concentration in low-intensity regions, and a large number of small cracks are produced before a large microseismic event occurs. The microseismic source is dispersed again once the regional stress is released. The entire system achieves a critical state. There is small cracks coalescence at a particular moment, which triggers a large-energy microseismic event. Therefore, it exhibits the phenomenon of power-law growth of the correlation length before the occurrence of the large-energy microseismic event. Moreover, statistical analysis of the bond length and frequency of SLC is performed. The result is that three non-scale ranges are identified. The turning points of the first two nonscale ranges are 180 m and 240 m, respectively, while the turning points of the second and third non-scale ranges are both approximately 450 m. The difference between the first turning points is due to the artificial disturbance, while the second turning point is affected by the geological environment.

Effect of Heat Treatment on Microstructure and Properties of FGH4096M Superalloy Processed by Selective Laser Melting

Zhibo Hao,Tian Tian,Shiqing Peng,Changchun Ge,Xinggang Li,Chonglin Jia,Chuan Guo,Qiang Zhu 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.8

A self-designed nickel-based superalloy, designated as FGH4096M, was prepared by selective laser melting (SLM). Differentheat treatments were performed to improve the mechanical properties of the SLM alloy through optimizing the microstructuresand the features of γ′ precipitates. Compared with the as-deposited alloy, the columnar grains with dendritic structuresand equiaxed structures were retained in the alloy after direct aging, but a large amount of tertiary γ′ phase precipitated,especially around the sub-grain boundaries, resulting in the highest tensile strength but the lowest elongation. During solidsolution and aging treatment (SSA), the recovery and recrystallization occurring in the alloy facilitated the grains to beequiaxed with the increase of solution temperature. For lower solution temperature (below 1100 ℃), the secondary γ′ precipitatesdecreased with the increase of solution temperature, while the tertiary γ′ precipitates from the subsequent agingprocess gradually increased; for higher solution temperature over 1100 ℃, exceeding the complete dissolution temperatureof the γ′ phase, only tertiary γ′ precipitates from the subsequent aging process were uniformly distributed in the alloy. Afterdouble solid solution (1170 ℃ + 1050 ℃) + aging heat treatment (DSSA), there were three sizes of γ′ precipitates in thealloy. In general, the SLM + SSA (1130 ℃) alloy obtained the best comprehensive properties, which could be related tothe homogenized microstructures and the uniform and dense distribution of single sized tertiary γ′ precipitates in the alloy.

THE ZEROS DISTRIBUTION OF SOLUTIONS OF HIGHER ORDER DIFFERENTIAL EQUATIONS IN AN ANGULAR DOMAIN

Zhibo Huang,Zongxuan Chen 대한수학회 2010 대한수학회보 Vol.47 No.3

In this paper, we investigate the zeros distribution and Borel direction for the solutions of linear homogeneous differential equation f(n) + An−2(z)f(n−2) + · · · + A1(z)f' + A0(z)f = 0 (n ≥ 2)in an angular domain. Especially, we establish a relation between a cluster ray of zeros and Borel direction.

Multiple damages detection in beam based approximate waveform capacity dimension

Zhibo Yang,Xuefeng Chen,Shaohua Tian,Zhengjia He 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.41 No.5

A number of mode shape-based structure damage identification methods have been verified by numerical simulations or experiments for on-line structure health monitoring (SHM). However, many of them need a baseline mode shape generated by the healthy structure serving as a reference to identify damages. Otherwise these methods can hardly perform well when multiple cracks conditions occur. So it is important to solve the problems above. By aid of the fractal dimension method (FD), Qiao and Wang proposed a generalized fractal dimension (GFD) to detect the delamination damage. As a modification of GFD, Qiao and Cao proposed the approximate waveform capacity dimension (AWCD) technique to simplify the calculation of fractal and overcome the false peak appearing in the high mode shapes. Based on their valued work, this paper combined and applied the AWCD method and curvature mode shape data to detect multiple damages in beam. In the end, the identification properties of the AWCD for multiple damages have been verified by groups of Monte Carlo simulations and experiments.

Properties on $q$-difference Riccati equation

Zhibo Huang,Ran-Ran Zhang 대한수학회 2018 대한수학회보 Vol.55 No.6

In this paper, we investigate a certain type of $q$-difference Riccati equation in the complex plane. We prove that $q$-difference Riccati equation possesses a one parameter family of meromorphic solutions if it has three distinct meromorphic solutions. Furthermore, we find that all meromorphic solutions of $q$-difference Riccati equation and corresponding second order linear $q$-difference equation can be expressed by $q$-gamma function if this $q$-difference Riccati equation admits two distinct rational solutions and $q\in\mathbb{C}$ such that $0<|q|<1$. The growth and value distribution of differences of meromorphic solutions of $q$-difference Riccati equation are also treated.

Value distribution and uniqueness on q-differences of meromorphic functions

Zhibo Huang 대한수학회 2013 대한수학회보 Vol.50 No.4

In this paper, by using the q-difference analogue of lemma on the logarithmic derivative lemma to re-establish some estimates of Nevanlinna characteristics of f(qz), we deal with the value distribution and uniqueness of certain types of q-difference polynomials.

Boiling heat transfer characteristics of bionic flower bud structure microchannels

Zhibo Tang,Chengchao Wang,Cong Qi,Yuwei Wang,Lanqi Chen 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.12

In order to improve the boiling heat transfer capacity within the microstructure, a superhydrophilic surfacemodel with a bionic flower bud structure was established and the flow-boiling heat transfer characteristics weresimulated. The temperature, velocity and vapor phase distribution contours under different working conditions wereobtained. The effects of different flower spacings, superheat degrees and surfaces on boiling heat transfer were discussed. The study found that the droplet has more vaporization cores on the superhydrophilic surface, and the bubblescan effectively destroy the velocity and temperature boundary layers, thereby enhancing the boiling heat transfer ability. The heat transfer area under the narrow flower spacing is larger, and the vaporization core is more, which is moreconducive to boiling heat transfer. When the superheat degree is 80 K, the superhydrophilic surface with the flowerspacing L=0 m has the strongest heat transfer ability, which is 1.59 times that of the common surface, and the masstransfer rate is increased by 23.5%.

Study of Material Removal Behavior during Laser-assisted Ultrasonic Dressing of Diamond Wheel

Zhibo Yang,Shiyu Zhang,Junchen Hu,Zhen Zhang,Kaiqiang Li,Bo Zhao 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.1

Laser-assisted ultrasonic dressing (LUD) of the removal behavior of diamond wheel material is investigated by simulation and experimental method. The finite element model of diamond wheel is constructed for simulation during LUD. The effect of parameters of LUD process on the dressing force is discussed according to the simulation results. LUD experiments of diamond wheels are carried out after obtaining optimization of parameter. The dressing force obtained from simulation and experiments are compared. It is found that the variation tendency of simulated dressing force is in agreement with the experimental result. This indicates that the simulation results can be effectively used for the selection of process’ parameters.