Three-dimensional Printed Mg-Doped β-TCP Bone Tissue Engineering Scaffolds: Effects of Magnesium Ion Concentration on Osteogenesis and Angiogenesis In Vitro

Yifan Gu,Jing Zhang,Xinzhi Zhang,Guiping Liang,Tao Xu,Wei Niu 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.4

BACKGROUND: Three-dimensional (3D) printed bone tissue engineering scaffolds have been widely used in research and clinical applications. b-TCP is a biomaterial commonly used in bone tissue engineering to treat bone defects, and its multifunctionality can be achieved by co-doping different metal ions. Magnesium doping in biomaterials has been shown to alter physicochemical properties of cells and enhance osteogenesis. METHODS: A series of Mg-doped TCP scaffolds were manufactured by using cryogenic 3D printing technology and sintering. The characteristics of the porous scaffolds, such as microstructure, chemical composition, mechanical properties, apparent porosity, etc., were examined. To further study the role of magnesium ions in simultaneously inducing osteogenesis and angiogenesis, human bone marrow mesenchymal stem cells (hBMSCs) and human umblical vein endothelial cells (HUVECs) were cultured in scaffold extracts to investigate cell proliferation, viability, and expression of osteogenic and angiogenic genes. RESULTS: The results showed that Mg-doped TCP scaffolds have the advantages of precise design, interconnected porous structure, and similar compressive strength to natural cancellous bone. hBMSCs and HUVECs exhibit high proliferation rate, cell morphology and viability in a certain amount of Mg2?. In addition, this concentration of magnesium can also increase the expression levels of osteogenic and angiogenic biomarkers. CONCLUSION: A certain concentration of magnesium ions plays an important role in new bone regeneration and reconstruction. It can be used as a simple and effective method to enhance the osteogenesis and angiogenesis of bioceramic scaffolds, and support the development of biomaterials and bone tissue engineering scaffolds.

Site-specific N-glycosylation identification of recombinant human lectin-like oxidized low density lipoprotein receptor-1 (LOX-1)

Yifan Qian,Xingwang Zhang,Lei Zhou,Shifang Ren,Jianxin Gu 한국당과학회 2012 한국당과학회 학술대회 Vol.2012 No.1

Human LOX-1/OLR 1 plays a key role in atherogenesis and endothelial dysfunction. The N-glycosylation of LOX-1 has been shown to affect its biological functions in vivo and modulate the pathogenesis of atherosclerosis. However, the N-glycosylation pattern of LOX-1 has not been described yet. The present study was aimed at elucidating the N-glycosylation of recombinanthuman LOX-1 with regard to N-glycan profile and N-glycosylation sites. Here, an approach using nonspecific protease (Pronase E) digestion followed by MALDI-QIT-TOF MS and multistage MS (MS3) analysis is explored to obtain site-specificN- glycosylation information of recombinanthuman LOX-1, in combination with glycan structure confirmation through characterizing released glycans using tandem MS. The results reveal that N-glycans structures as well as their corresponding attached site of LOX-1 can be identified simultaneously by direct MS analysis of glycopeptides from non-specific protease digestion. With this approach, one potential glycosylation site of recombinanthuman LOX-1 on Asn139 is readily identified and found to carry heterogeneous complex type N-glycans. In addition, manual annotation of multistage MS data utilizing diagnostic ions, which were found to be particularly useful in defining the structure of glycopeptides and glycans was addressed for proper spectra interpretation. The findings described herein will shed new light on further research of the structure-function relationships of LOX-1 N-glycan.

Consideration of Control-Loop Interaction in Transient Stability of Grid-Following Inverters using Bandwidth Separation Method

Yifan Zhang,Yitong Li,Yunjie Gu,Timothy C. Green 전력전자학회 2023 ICPE(ISPE)논문집 Vol.2023 No.-

Grid-following inverters have been widely adopted as a grid interface for renewable energy resources, but ensuring their transient stability has been a growing challenge in part because of a lack of clarity on how interactions between the inverter’s various outer control loops impact transient response. In this paper, the nonlinear dynamics and transient stability of grid-following inverters are investigated, where not only the phase-locked loop (PLL) but also the DC-link voltage control (DVC) and the AC terminal voltage control (TVC) are taken into account. The use of bandwidth separation method is proposed, though which the original differential equations can be simplified, and their order can be reduced, providing that the separation between their bandwidths is sufficiently large. Analysis of the interaction between the DVC and the PLL is developed, proving that this interaction negatively impacts stability. Furthermore, optimal combinations of bandwidth of PLL and DVC are identified under various types of grid faults. The impact of TVC on transient stability is analyzed. All of the results and the conclusions drawn from them are verified by simulation.

Serial Frozen Fecal Microbiota Transplantation in the Treatment of Chronic Intestinal Pseudo-obstruction: A Preliminary Study

( Lili Gu ),( Chao Ding ),( Hongliang Tian ),( Bo Yang ),( Xuelei Zhang ),( Yue Hua ),( Yifan Zhu ),( Jianfeng Gong ),( Weiming Zhu ),( Jieshou Li ),( Ning Li ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2017 Journal of Neurogastroenterology and Motility (JNM Vol.23 No.2

Background/Aims Chronic intestinal pseudo-obstruction (CIPO) is a serious, life-threatening motility disorder that is often related to bacterial overgrowth. Fecal microbiota transplantation (FMT) results in restoration of the normal intestinal microbial community structure. We investigated the efficacy of FMT in the treatment of CIPO patients. Methods Nine patients (age 18-53 years) with CIPO were enrolled in this prospective, open-label study. Patients received FMT for 6 consecutive days through nasojejunal (NJ) tubes and were followed up for 8 weeks after treatment. We evaluated the rate of clinical improvement and remission, feeding tolerance of enteral nutrition, and CT imaging scores of intestinal obstructions. Lactulose hydrogen breath tests were performed before FMT and 8 weeks after FMT to evaluate for the presence small intestinal bacterial overgrowth (SIBO). Results FMT significantly alleviated bloating symptoms, and symptoms of pain were relieved 2 weeks after FMT. Enteral nutrition administered through a NJ tube after FMT was well-tolerated by 66.7% (6/9) of patients. CT scores of intestinal obstructions were significantly reduced after FMT (P = 0.014). SIBO was eliminated in 71.0% (5/7) of patients. Conclusions This pilot study demonstrated the safety of using FMT. FMT may relieve symptoms in selected patients with CIPO. FMT may also improve patient tolerance of enteral nutrition delivered via a NJ tube. (J Neurogastroenterol Motil 2017;23:289-297)

An important link between the gut microbiota and the circadian rhythm: imply for treatments of circadian rhythm sleep disorder

Yufei Tian,Wei Yang,Gang Chen,Chuanlong Men,Yifan Gu,Ruilin Zhang,Laiyou Wang,Xin Zhang 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.2

Currently, gut microbiota living in the gastrointestinaltract, plays an important role in regulatinghost’s sleep and circadian rhythms. As a tool, gut microbiotahas great potential for treating circadian disturbanceand circadian insomnia. However, the relationship betweengut microbiota and circadian rhythms is still unclear, andthe mechanism of action has still been the focus ofmicrobiome research. Therefore, this article summarizesthe current evidences associating gut microbiota with factorsthat impact host circadian rhythms neurology sleepdisorder. Moreover, we discuss the changes to these systemsin sleep disorder and the potential mechanism ofintestinal microbiota in regulating circadian rhythms neurologysleep disorder via microbial metabolites. Meanwhile,based on the role of intestinal flora, it is provided anovel insight into circadian related insomnia and will bebenefit the dietary treatment of circadian disturbance andthe circadian related insomnia.