Some results of f-biharmonic maps into a Riemannian manifold of non-positive sectional curvature

Guoqing He,Jing Li,Peibiao Zhao 대한수학회 2017 대한수학회보 Vol.54 No.6

The authors investigate $f$-biharmonic maps $u: (M,g)\rightarrow(N,h)$ from a Riemannian manifold into a Riemannian manifold with non-positive sectional curvature, and derive that if $\int_{M}f^{p}|\tau(u)|^{p}dv_{g}<\infty$, $\int_{M}|\tau(u)|^{2}dv_{g}<\infty$ and $\int_{M}|du|^{2}dv_{g}<\infty$, then $u$ is harmonic. When $u$ is an isometric immersion, the authors also get that if $u$ satisfies some integral conditions, then it is minimal. These results give an affirmative partial answer to conjecture 4 (generalized Chen's conjecture for $f$-biharmonic submanifolds).

SOME RESULTS OF f-BIHARMONIC MAPS INTO A RIEMANNIAN MANIFOLD OF NON-POSITIVE SECTIONAL CURVATURE

He, Guoqing,Li, Jing,Zhao, Peibiao Korean Mathematical Society 2017 대한수학회보 Vol.54 No.6

The authors investigate f-biharmonic maps u : (M, g) ${\rightarrow}$ (N, h) from a Riemannian manifold into a Riemannian manifold with non-positive sectional curvature, and derive that if $\int_{M}f^p{\mid}{\tau}(u){\mid}^pdv_g$ < ${\infty}$, $\int_{M}{\mid}{\tau}(u){\mid}^2dv_g$ < ${\infty}$ and $\int_{M}{\mid}du{\mid}^2dv_g$ < ${\infty}$, then u is harmonic. When u is an isometric immersion, the authors also get that if u satisfies some integral conditions, then it is minimal. These results give an affirmative partial answer to conjecture 4 (generalized Chen's conjecture for f-biharmonic submanifolds).

Nitric Oxide Alleviates Deterioration and Preserves Antioxidant Properties in ‘Tainong’ Mango Fruit During Ripening

Yanfang Ren,Junyu He,Houyu Liu,Guoqing Liu,Xiaoling Ren 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.1

We investigated the effects of nitric oxide (NO) on quality, membrane lipid peroxidation, and antioxidantenzymes in mango (Mangifera indica L. cv ‘Tainong’) fruit during ripening. Fruits were treated with 0.25 mmol·L-1sodium nitroprusside (SNP) by the immersion method and stored at 23°C for 20 days. SNP treatment significantlysuppressed the respiration rate, enhanced fruit firmness, and decreased the rot index, peel color index, and weightloss in the fruit. This treatment also slowed the increase in soluble solids content (SSC) while maintaining highlevels of titratable acidity (TA), ascorbic acid (AsA), and phenolic compounds. Furthermore, SNP treatment enhancedthe antioxidant activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and reduced theactivities of lipoxygenase (LOX) and polyphenol oxidase (PPO) in mango fruit, which was associated with the reducedaccumulation of malondialdehyde (MDA), superoxide anion radical (O2•-), and hydrogen peroxide (H2O2) comparedwith the control. Therefore, the addition of exogenous SNP has the potential for improving quality and prolongingthe shelf life of mango fruits by protecting them against oxidative damage caused by ROS during ripening.

Gamma radiation shielding properties of WO3/Bi2O3/waterborne polyurethane composites

Wu Zhengxin,Li Yong,Yan Qiang,Liu Guoqing,Liu Yong,Wang Guowei,He Liang 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.81 No.3

In this study, the gamma-ray shielding performance and the mechanical properties of waterborne polyurethane (WPU) composites embedded with tungsten trioxide (WO3) and bismuth trioxide (Bi2O3) were investigated. The results indicated that the shielding properties of the composites against gamma rays increased with WO3/Bi2O3 loading and that nanocomposites were better able to attenuate gamma rays than microcomposites. The mass ratio of WO3 and Bi2O3 in the composite played an important role in attenuating low-energy gamma rays. With the increment of Bi2O3 loading, the composite’s ability to attenuate 59.5 keV and 121.8 keV gamma rays improved, whereas higher WO3 contents enhanced the ability to attenuate 81 keV gamma ray. In terms of mechanical properties, with WO3/Bi2O3 loading increased, the tensile strength of composites frst increased and then decreased, and the elongation at break steadily decreased. Gamma irradiation also improved the mechanical properties of the WPU composites, as indicated by the increase in tensile strength as the irradiation dose increased from 50 to 200 kGy.

Sequence Impedance Modeling and Frequency Characteristic Analysis of MMC-based HVDC

Tong Huang,Xin Chen,Guanghui Li,Guoqing He 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Modular multilevel converter (MMC) has emerged as a preferred technology for high-voltage dc (HVDC) transmission, while many HVDC-MMC projects have been reported resonance problems. The existing researches show that stability of a HVDC-grid system is decided by both the sequence impedance characteristic of HVDC-MMC and power grid, and due to coupling effect, the power grid impedance will also impact the HVDCMMC impedance characteristic. Multi-harmonic linearization method will be adopted in this paper to develop a HVDC-MMC analytical sequence impedance model. Then the developed model is used to illustrate the effect of the power control loop as well as the bandwidth of other controllers on HVDC-MMC impedance characteristic. Finally, based on the sequence impedance model considering coupling effect, the influence of HVDC-MMC bandwidth on the system stability will be analyzed as well.

Delayed Terminal Ileal Perforation in a Relapsed/Refractory B-Cell Lymphoma Patient with Rapid Remission Following Chimeric Antigen Receptor T-Cell Therapy

Yongxian Hu,Jiasheng Wang,Chengfei Pu,Kui Zhao,Qu Cui,Guoqing Wei,Wenjun Wu,Lei Xiao,Yang Xiao,Jinping Wang,Zhao Wu,He Huang 대한암학회 2018 Cancer Research and Treatment Vol.50 No.4

Chimeric antigen receptor T-cell strategy targeting CD19 (CART19) has prominent anti-tumor effect for relapsed/refractory B-cell lymphomas. CART19-associated complications have been gradually recognized, however, late-onset complications have not been extensively studied. Herein, for the first time we report a diffuse large B-cell lymphoma patient with terminal ileum involvement obtained rapid remission and developed spontaneous terminal ileal perforation 38 days following CART19 infusion. The late-onset perforation reminds us that, for the safety of CART treatment, more cautions are warranted for the management of delayed GI complications.

Frequency Characteristic and Impedance Analysis on Three-Phase Grid-Connected Inverters Based on DDSRF-PLL

Xiangqiang Wu,Tong Huang,Xin Chen,Haibing Hu,Guoqing He 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Decoupled double synchronous reference frame phase locked loop (DDSRF-PLL) can effectively eliminate negative-sequence fundamental frequency component, which means the PLL control loop will have an effect on the frequency characteristics and stability of gridconnected inverters. Based on the three-phase LCL-type grid-connected inverter, the positive- and negative-sequence output impedance model of the grid-connected inverter and the frequency characteristics of DDSRF-PLL were firstly derived. Meanwhile, the regulator parameters of DDSRFPLL were designed and its effect on impedance stability of inverter was analyzed. Then, the frequency characteristics of DDSRF-PLL and the output impedance model of the grid-connected inverter were verified by the simulation and experimental results. Finally, the stability of the gridconnected with different PLL bandwidths was analyzed and verified by experimental results.

Antiproliferative Activities of Parthenolide and Golden Feverfew Extract Against Three Human Cancer Cell Lines

Changqing Wu,Feng Chen,James W. Rushing,Xi Wang,김현진,George Huang,Vivian Haley-Zitlin,Guoqing He 한국식품영양과학회 2006 Journal of medicinal food Vol.9 No.1

The medicinal herb feverfew [Tanacetum parthenium (L.) Schultz-Bip.] has long been used as a folk remedyfor the treatment of migraine and arthritis. Parthenolide, a sesquiterpene lactone, is considered to be the primary bioactivecompound in feverfew having anti-migraine, anti-tumor, and anti-inflammatory properties. In this study we determined, throughin vitrobioassays, the inhibitory activity of parthenolide and golden feverfew extract against two human breast cancer celllines (Hs605T and MCF-7) and one human cervical cancer cell line (SiHa). Feverfew ethanolic extract inhibited the growthof all three types of cancer cells with a half-effective concentration (EC50) of 1.5 mg/mL against Hs605T, 2.1 mg/mL againstMCF-7, and 0.6 mg/mL against SiHa. Among the tested constituents of feverfew (i.e., parthenolide, camphor, luteolin, andapigenin), parthenolide showed the highest inhibitory effect with an EC50 against Hs605T, MCF-7, and SiHa of 2.6 .g/mL,2.8 .g/mL, and 2.7 .g/mL, respectively. Interactions between parthenolide and flavonoids (apigenin and luteolin) in fever-few extract also were investigated to elucidate possible synergistic or antagonistic effects. The results revealed that apigeninand luteolin might have moderate to weak synergistic effects with parthenolide on the inhibition of cancer cell growth ofHs605T, MCF-7, and SiHa.

Establishment of a Tm-shi Method for Detection of Cat-Derived Hookworms

Yeqi Fu,Yunqiu Liu,Asmaa M.I. Abuzeid,Yue Huang,Xue Zhou,Long He,Qi Zhao,Xiu Li,Jumei Liu,Rongkun Ran,Guoqing Li 대한기생충학ㆍ열대의학회 2019 The Korean Journal of Parasitology Vol.57 No.1

Melting temperature shift (Tm-shift) is a new detection method that analyze the melting curve on real-time PCR thermocycler using SYBR Green I fluorescent dye. To establish a Tm-shift method for the detection of Ancylostoma ceyl- anicum and A. tubaeforme in cats, specific primers, with GC tail of unequal length attached to their 5 ́ end, were designed based on 2 SNP loci (ITS101 and ITS296) of the internal transcribed spacer 1 (ITS1) sequences. The standard curve of Tm-shift was established using the standard plasmids of A. ceylanicum (AceP) and A. tubaeforme (AtuP). The Tm-shift method stability, sensitivity, and accuracy were tested with reference to the standard curve, and clinical fecal samples were also examined. The results demonstrated that the 2 sets of primers based on the 2 SNPs could accurately distin- guish between A. ceylanicum and A. tubaeforme. The coefficient of variation (CV) of Tm- values of AceP and AtuP was 0.07% and 0.06% in ITS101 and was 0.06% and 0.08% in ITS296, respectively. The minimum detectable DNA concen- tration was 5.22×10-6 and 5.28×10-6 ng/μl samples of AceP and AtuP, respectively. The accuracy of Tm-shift method reached 100% based on examination of 10 hookworm DNA samples with known species. In the clinical detection of hookworm in 69 stray cat fecal sample, the Tm-shift detection results were consistent with the microscopic examination and successfully differentiated between the 2-hookworm species. In conclusion, the developed method is a rapid, sensi- tive and accurate technique and can provide a promising tool for clinical detection and epidemiological investigation of cat-derived hookworms.

Mitochondrial Genome Sequence of Echinostoma revolutum from Red-Crowned Crane (Grus japonensis)

Rongkun Ran,Qi Zhao,Asmaa M.I. Abuzeid,Yue Huang,Yunqiu Liu,Yongxiang Sun,Long He,Xiu Li,Jumei Liu,Guoqing Li 대한기생충학ㆍ열대의학회 2020 The Korean Journal of Parasitology Vol.58 No.1

Echinostoma revolutum is a zoonotic food-borne intestinal trematode that can cause intestinal bleeding, enteritis, and diarrhea in human and birds. To identify a suspected E. revolutum trematode from a red-crowned crane (Grus japonensis) and to reveal the genetic characteristics of its mitochondrial (mt) genome, the internal transcribed spacer (ITS) and complete mt genome sequence of this trematode were amplified. The results identified the trematode as E. revolutum. Its entire mt genome sequence was 15,714 bp in length, including 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and one non-coding region (NCR), with 61.73% A+T base content and a significant AT preference. The length of the 22 tRNA genes ranged from 59 bp to 70 bp, and their secondary structure showed the typical cloverleaf and D-loop structure. The length of the large subunit of rRNA (rrnL) and the small subunit of rRNA (rrnS) gene was 1,011 bp and 742 bp, respectively. Phylogenetic trees showed that E. revolutum and E. miyagawai clustered together, belonging to Echinostomatidae with Hypoderaeum conoideum. This study may enrich the mitochondrial gene database of Echinostoma trematodes and provide valuable data for studying the molecular identification and phylogeny of some digenean trematodes.