SOME REMARKS ON VECTOR-VALUED TREE MARTINGALES

He, Tong-Jun Korean Mathematical Society 2012 대한수학회지 Vol.49 No.2

Our first aim of this paper is to define maximal operators a-quadratic variation and of a-conditional quadratic variation for vectorvalued tree martingales and to show that these maximal operators and maximal operators of vector-valued tree martingale transforms are all sublinear operators. The second purpose is to prove that maximal operator inequalities of a-quadratic variation and of a-conditional quadratic variation for vector-valued tree martingales hold provided 2 ${\leq}$ a < $\infty$ by means of Marcinkiewicz interpolation theorem. Based on a result of reference [10] and using Marcinkiewicz interpolation theorem, we also propose a simple proof of maximal operator inequalities for vector-valued tree martingale transforms, under which the vector-valued space is a UMD space.

Some remarks on vector-valued tree martingales

Tong-jun He 대한수학회 2012 대한수학회지 Vol.49 No.2

Our rst aim of this paper is to dene maximal operators of a-quadratic variation and of a-conditional quadratic variation for vectorvalued tree martingales and to show that these maximal operators and maximal operators of vector-valued tree martingale transforms are all sublinear operators. The second purpose is to prove that maximal operator inequalities of a-quadratic variation and of a-conditional quadratic variation for vector-valued tree martingales hold provided 2 <a < 1 by means of Marcinkiewicz interpolation theorem. Based on a result of reference [10] and using Marcinkiewicz interpolation theorem, we also propose a simple proof of maximal operator inequalities for vector-valued tree martingale transforms, under which the vector-valued space is a UMD space.

Protective effect of Cordyceps militaris against hydrogen peroxide-induced oxidative stress in vitro

He, Mei Tong,Lee, Ah Young,Park, Chan Hum,Cho, Eun Ju The Korean Nutrition Society 2019 Nutrition Research and Practice Vol.13 No.4

BACKGROUND/OBJECTIVES: Excessive production of reactive oxygen species (ROS) such as hydroxyl (${\cdot}OH$), nitric oxide (NO), and hydrogen peroxide ($H_2O_2$) is reported to induce oxidative stress. ROS generated by oxidative stress can potentially damage glial cells in the nervous system. Cordyceps militaris (CM), a kind of natural herb widely found in East Asia. In this study, we investigated the free radical scavenging activity of the CM extract and its neuroprotective effects in $H_2O_2$-induced C6 glial cells. MATERIALS/METHODS: The ethanol extract of CM ($100-1,000{\mu}g/mL$) was used to measure DPPH, ${\cdot}OH$, and NO radical scavenging activities. In addition, hydrogen peroxide ($H_2O_2$)-induced C6 glial cells were treated with CM at $0.5-2.5{\mu}g/mL$ for measurement of cell viability, ROS production, and protein expression resulting from oxidative stress. RESULTS: The CM extract showed high scavenging activities against DPPH, ${\cdot}OH$, and NO radicals at concentration of $1,000{\mu}g/mL$. Treatment of CM with $H_2O_2$-induced oxidative stress in C6 glial cells significantly increased cell viability, and decreased ROS production. Cyclooxygenase-2 and inducible nitric oxide synthase protein expression was down-regulated in CM-treated groups. In addition, the protein expression level of phospho-p38 mitogen-activated protein kinase (p-p38 MAPK), phospho-c-Jun N-terminal kinase (p-JNK), and phospho-extracellular regulated protein kinases (p-ERK) in $H_2O_2$-induced C6 glial cells was down-regulated upon CM administration. CONCLUSION: CM exhibited radical scavenging activity and protective effect against $H_2O_2$ as indicated by the increased cell viability, decreased ROS production, down-regulation of inflammation-related proteins as well as p-p38, p-JNK, and p-ERK protein levels. Therefore, we suggest that CM could play the protective role from oxidative stress in glial cells.

Effect of Sn Micro-Alloying on Recrystallization Nucleation and Growth Processes of Ferritic Stainless Steels

Tong He,Yang Bai,Xiuting Liu,Dan Guo,Yandong Liu 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.4

We investigated the Effect of Sn micro-alloying on recrystallization nucleation and growth processes of ferritic stainlesssteels. The as-received hot rolled sheets were cold rolled up to 80% reduction and then annealed at 740–880 °C for 5 min. The cold rolling and recrystallization microstructures and micro-textures of Sn-containing and Sn-free ferritic stainless steelswere all determined by electron backscatter diff raction. Our Results show that Sn micro-alloying has important Effects onrecrystallization nucleation and growth processes of ferritic stainless steels. Sn micro-alloying conduces to grain fragmentationin the deformation band, more fragmented grains are existed in Sn-containing cold rolled sheets, which provides moresites for recrystallization nucleation. Sn micro-alloying also promotes recrystallization process and inhibits the growth ofrecrystallized grains. The recrystallization nucleation and growth mechanism of Sn-containing and Sn-free ferritic stainlesssteels are both characterized by orientation nucleation and selective growth, but Sn micro-alloying promotes the formation ofγ-oriented grains. Furthermore, Sn micro-alloying contributes to the formation of Σ13b CSL boundaries and homogeneousγ-fi ber texture. Combining the results of microstructure and micro-texture, the formability of Sn-containing ferritic stainlesssteels will be improved to some extent.

Cordyceps militaris Protects Hydrogen Peroxide-Induced Oxidative Stress

Mei Tong He,Chan Hum Park,Hyun Young Kim,Eun Ju Cho 한국식품영양과학회 2018 한국식품영양과학회 학술대회발표집 Vol.2018 No.10

Protective effect of Cordyceps militaris against hydrogen peroxide-induced oxidative stress in vitro

Mei Tong He,Ah Young Lee,Chan Hum Park,Eun Ju Cho 한국영양학회 2019 Nutrition Research and Practice Vol.13 No.4

BACKGROUND/OBJECTIVES: Excessive production of reactive oxygen species (ROS) such as hydroxyl (·OH), nitric oxide (NO), and hydrogen peroxide (H₂O₂) is reported to induce oxidative stress. ROS generated by oxidative stress can potentially damage glial cells in the nervous system. Cordyceps militaris (CM), a kind of natural herb widely found in East Asia. In this study, we investigated the free radical scavenging activity of the CM extract and its neuroprotective effects in H₂O₂-induced C6 glial cells. MATERIALS/METHODS: The ethanol extract of CM (100-1,000 μg/mL) was used to measure DPPH, ·OH, and NO radical scavenging activities. In addition, hydrogen peroxide (H₂O₂)-induced C6 glial cells were treated with CM at 0.5-2.5 μg/mL for measurement of cell viability, ROS production, and protein expression resulting from oxidative stress. RESULTS: The CM extract showed high scavenging activities against DPPH, ·OH, and NO radicals at concentration of 1,000 μg/mL. Treatment of CM with H₂O₂-induced oxidative stress in C6 glial cells significantly increased cell viability, and decreased ROS production. Cyclooxygenase-2 and inducible nitric oxide synthase protein expression was down-regulated in CM-treated groups. In addition, the protein expression level of phospho-p38 mitogen-activated protein kinase (p-p38 MAPK), phospho-c-Jun N-terminal kinase (p-JNK), and phospho-extracellular regulated protein kinases (p-ERK) in H₂O₂-induced C6 glial cells was down-regulated upon CM administration. CONCLUSION: CM exhibited radical scavenging activity and protective effect against H₂O₂ as indicated by the increased cell viability, decreased ROS production, down-regulation of inflammation-related proteins as well as p-p38, p-JNK, and p-ERK protein levels. Therefore, we suggest that CM could play the protective role from oxidative stress in glial cells.

Protective role of Cordyceps militaris in Aβ1–42-induced Alzheimer’s disease in vivo

Mei Tong He,이아영,김지현,박찬흠,신유수,조은주 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.3

According to the ‘‘amyloid cascade hypothesis’’,amyloid-beta (Ab) protein occupied one of the risk factorsof Alzheimer’s disease (AD). Cordyceps militaris (CM)has been reported to exert anti-inflammatory, anti-oxidant,and neuroprotective activities; however, its activity againstcognitive dysfunction has not been studied yet. In thisstudy, the CM ethanol extract was administered with a doseof 100 or 200 mg/kg for 2 weeks, and behavioral assessmentswere performed for learning and memory function inAb1–42-induced AD mice models. Supplementation withCM extract enhanced new route consciousness and novelobject recognition, and in the Morris water maze test, CMadministeredgroups showed less time to reach to the hiddenplatform compared with the control group. Moreover,the CM extract inhibited nitric oxide production and lipidperoxidation in the brain, liver, and kidney. The presentstudy indicated that CM could have the protective rolefrom cognitive impairment and progression of AD.

Improved development of somatic cell cloned bovine embryos by a mammary gland epithelia cells in vitro model

XiaoYing He,LiBing Ma,Xiao-ning He,Wan-tong Si,Yue-Mao Zheng 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.2

Previous studies have established a bovine mammary gland epithelia cells in vitro model by the adenovirus-mediated telomerase (hTERT-bMGEs). The present study was conducted to confirm whether hTERT-bMGEs were effective target cells to improve the efficiency of transgenic expression and somatic cell nuclear transfer (SCNT). To accomplish this, a mammary-specific vector encoding human lysozyme and green fluorescent protein was used to verify the transgenic efficiency of hTERT-bMGEs, and untreated bovine mammary gland epithelial cells (bMGEs) were used as a control group. The results showed that the hTERT-bMGEs group had much higher transgenic efficiency and protein expression than the bMGEs group. Furthermore, the nontransgenic and transgenic hTERT-bMGEs were used as donor cells to evaluate the efficiency of SCNT. There were no significant differences in rates of cleavage or blastocysts or hatched blastocysts of cloned embryos from nontransgenic hTERT-bMGEs at passage 18 and 28 groups (82.8% vs. 81.9%, 28.6% vs. 24.8%, 58.6% vs. 55.3%, respectively) and the transgenic group (80.8%, 26.5% and 53.4%); however, they were significantly higher than the bMGEs group (71.2%, 12.8% and 14.8%), (p < 0.05). We confirmed that hTERT-bMGEs could serve as effective target cells for improving development of somatic cell cloned cattle embryos.

Combination of Carthamus tinctorius L. and Taraxacum coreanum Exerts Synergistic Effect on Learning and Memory Function in Amyloid Beta-Injected Mice

Mei Tong He,Chan Hum Park,Jae Yang Lee,Yu Su Shin,Eun Ju Cho 한국식품영양과학회 2018 한국식품영양과학회 학술대회발표집 Vol.2018 No.10

Photobiomodulation Facilitates Rat Cutaneous Wound Healing by Promoting Epidermal Stem Cells and Hair Follicle Stem Cells Proliferation

Wang Tong,Song Yajuan,Yang Liu,Liu Wei,He Zhen’an,Shi Yi,Song Baoqiang,Yu Zhou 한국조직공학과 재생의학회 2024 조직공학과 재생의학 Vol.21 No.1

Background: Cutaneous wound healing represents a common fundamental phenomenon requiring the participation of cells of distinct types and a major concern for the public. Evidence has confirmed that photobiomodulation (PBM) using near-infrared (NIR) can promote wound healing, but the cells involved and the precise molecular mechanisms remain elusive. Methods: Full-thickness skin defects with a diameter of 1.0 cm were made on the back of rats and randomly divided into the control group, 10 J, 15 J, and 30 J groups. The wound healing rate at days 4, 8, and 12 postoperatively was measured. HE and Masson staining was conducted to reveal the histological characteristics. Immunofluorescence staining was performed to label the epidermal stem cells (ESCs) and hair follicle stem cells (HFSCs). Western blot was performed to detect the expressions of proteins associated with ESCs and HFSCs. Cutaneous wound tissues were collected for RNA sequencing. Gene ontology and the Kyoto Encyclopedia of Genes and Genomes analysis was performed, and the hub genes were identified using CytoHubba and validated by qRT-PCR. Results: PBM can promote reepithelialization, extracellular matrix deposition, and wound healing, increase the number of KRT14+/PCNA+ ESCs and KRT15+/PCNA+ HFSCs, and upregulate the protein expression of P63, Krt14, and PCNA. Three hundred and sixty-six differentially expressed genes (DEGs) and 7 hub genes including Sox9, Krt5, Epcam, Cdh1, Cdh3, Dsp, and Pkp3 were identified. These DEGs are enriched in skin development, cell junction, and cadherin binding involved in cell–cell adhesion etc., while these hub genes are related to skin derived stem cells and cell adhesion. Conclusion: PBM accelerates wound healing by enhancing reepithelialization through promoting ESCs and HFSCs proliferation and elevating the expression of genes associated with stem cells and cell adhesion. This may provide a valuable alternative strategy to promote wound healing and reepithelialization by modulating the proliferation of skin derived stem cells and regulating genes related to cell adhesion. Background: Cutaneous wound healing represents a common fundamental phenomenon requiring the participation of cells of distinct types and a major concern for the public. Evidence has confirmed that photobiomodulation (PBM) using near-infrared (NIR) can promote wound healing, but the cells involved and the precise molecular mechanisms remain elusive. Methods: Full-thickness skin defects with a diameter of 1.0 cm were made on the back of rats and randomly divided into the control group, 10 J, 15 J, and 30 J groups. The wound healing rate at days 4, 8, and 12 postoperatively was measured. HE and Masson staining was conducted to reveal the histological characteristics. Immunofluorescence staining was performed to label the epidermal stem cells (ESCs) and hair follicle stem cells (HFSCs). Western blot was performed to detect the expressions of proteins associated with ESCs and HFSCs. Cutaneous wound tissues were collected for RNA sequencing. Gene ontology and the Kyoto Encyclopedia of Genes and Genomes analysis was performed, and the hub genes were identified using CytoHubba and validated by qRT-PCR. Results: PBM can promote reepithelialization, extracellular matrix deposition, and wound healing, increase the number of KRT14+/PCNA+ ESCs and KRT15+/PCNA+ HFSCs, and upregulate the protein expression of P63, Krt14, and PCNA. Three hundred and sixty-six differentially expressed genes (DEGs) and 7 hub genes including Sox9, Krt5, Epcam, Cdh1, Cdh3, Dsp, and Pkp3 were identified. These DEGs are enriched in skin development, cell junction, and cadherin binding involved in cell–cell adhesion etc., while these hub genes are related to skin derived stem cells and cell adhesion. Conclusion: PBM accelerates wound healing by enhancing reepithelialization through promoting ESCs and HFSCs proliferation and elevating the expression of genes associated with stem cells and cell adhesion. This may provide a valuable alternative strategy to promote wound healing and reepithelialization by modulating the proliferation of skin derived stem cells and regulating genes related to cell adhesion.