Preliminary numerical study of single bubble dynamics in swirl flow using volume of fluid method

Li, Zhongchun,Qiu, Zhifang,Du, Sijia,Ding, Shuhua,Bao, Hui,Song, Xiaoming,Deng, Jian Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.4

Spacer grid with mixing vane had been widely used in nuclear reactor core. One of the main feather of spacer grid with mixing vane was that strong swirl flow was formed after the spacer grid. The swirl flow not only changed the bubble generation in the near wall field, but also affected the bubble behaviors in the center region of the subchannel. The interaction between bubble and the swirl flow was one of the basic phenomena for the two phase flow modeling in fuel assembly. To obatin better understanding on the bubble behaviors in swirl flow, full three dimension numerical simulations were conducted in the present paper. The swirl flow was assumed in the cylindral calculation domain. The bubble interface was captured by Volume Of Fluid (VOF) method. The properties of saturated water and steam at different pressure were applied in the simulation. The bubble trajectory, motion, shape and force were obtained based on the bubble parameters captured by VOF. The simulation cases in the present study included single bubble with different size, at different angular velocity conditions and at different pressure conditions. The results indicated that bubble migrated to the center in swirl flow with spiral motion type. The lateral migration was mainly related to shear stress magnitude and bubble size. The bubble moved toward the center with high velocity when the swirl magnitude was high. The largest bubble had the highest lateral migration velocity in the present study range. The effect of pressure was small when bubble size was the same. The prelimenery simulation result would be beneficial for better understanding complex two phase flow phenomena in fuel assembly with spacer grid.

Characterization and function of a short peptidoglycan recognition protein from the Chinese oak silkworm, Antheraea pernyi

Li-Shang Dai,Cen Qian, LeiWang,Guo-Qing Wei,Qiu-Ning Liu,Yu Sun,Cong-Fen Zhang,Jun Li,Dong-Ran Liu,Bao-Jian Zhu,Chao-Liang Liu 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.4

Peptidoglycan recognition proteins (PGRPs) are conserved proteins in animals from insects to mammals and play an important role in immune response by recognizing peptidoglycan on microbial surfaces. In this study, a PGRP gene from Antheraea pernyi, named Ap-PGRP-A, was isolated and characterized. Sequence analysis revealed that the full-length cDNA of Ap-PGRP-A was 961 bp, containing a 40 bp 5′-untranslated sequence, a 339 bp 3′-untranslated region and an open reading frame of 582 bp. This gene encoded a putative protein of 193 amino acid residues. Phylogenetic analysis indicated that Ap-PGRP-A had the closest protein sequence similarity to Antheraea mylitta PGRP. The recombinant protein was successfully expressed in Escherichia coli cells and a rabbit anti-Ap-PGRP-A antibody was also prepared. Real-time quantitative reverse transcription-PCR analysis showed that Ap-PGRP-A was extensively expressed in the fat body, midgut, hemocyte,malpighian tubule and epidermis of A. pernyi, especially in the fat body and midgut. The expression levels of Ap-PGRP-A were significantly up-regulated by three types of microorganisms, and Ap-PGRP-A expression was more sensitive in response to the Gram-negative bacterium E. coli than the Gram-positive bacterium Bacillus subtilis or the fungus Beauveria bassiana. These data indicate that Ap-PGRP-A may play a role in the innate immune responses of A. pernyi.

Cloning of Phospholipase D from Grape Berry and Its Expression under Heat Acclimation

( Si Bao Wan ),( Wei Wang ),( Peng Fei Wen ),( Jian Ye Chen ),( Wei Fu Kong ),( Qiu Hong Pan ),( Ji Cheng Zhan ),( Li Tian ),( Hong Tao Liu ),( Wei Dong Huang ) 생화학분자생물학회 2007 BMB Reports Vol.40 No.4

Cloning of Phospholipase D from Grape Berry and Its Expression under Heat Acclimation

Wan, Si-Bao,Wang, Wei,Wen, Peng-Fei,Chen, Jian-Ye,Kong, Wei-Fu,Pan, Qiu-Hong,Zhan, Ji-Cheng,Tian, Li,Liu, Hong-Tao,Huang, Wei-Dong Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.4

To investigate whether phospholipase D (PLD, EC 3.1.4.4) plays a role in adaptive response of post-harvest fruit to environment, a PLD gene was firstly cloned from grape berry (Vitis Vinifera L. cv. Chardonnay) using RT-PCR and 3'- and 5'-RACE. The deduced amino acid sequence (809 residues) showed 84.7% identity with that of PLD from Ricinus communis. The secondary structures of this protein showed the characteristic C2 domain and two active sites of a phospholipid-metabolizing enzyme. The PLD activity and its expression in response to heat acclimation were then assayed. The results indicated PLD was significantly activated at enzyme activity, as well as accumulation of PLD mRNA and synthesis of new PLD protein during the early of heat acclimation, primary suggesting that the grape berry PLD may be involved in the heat response in post-harvest grape berry. This work offers an important basis for further investigating the mechanism of post-harvest fruit adaptation to environmental stresses.

Transgenic NfFeSOD Sedum alfredii plants exhibited profound growth impairments and better relative tolerance to long-term abiotic stresses

Xiang Gao,Wen-Li Ai,Huan Gong,Li-Juan Cui,Bo-Xia Chen,Hong-Yi Luo,Zhong-Chun Zhang,Bao-Sheng Qiu 한국식물생명공학회 2016 Plant biotechnology reports Vol.10 No.2

Transgenic research was preformed by transferring a cyanobacterial (Nostoc flagelliforme) iron superoxide dismutase gene (NfFeSOD) into heavy metal hyperaccumulator Sedum alfredii via Agrobacterium-mediated method. Beyond expectation, NfFeSOD-overexpressing S. alfredii plants exhibited profound impairments, including plant growth retardation, abnormal root architecture, and reduced leaf greenness, photosynthetic efficiency and metal accumulation efficiency. Although transgenic plants appeared physiologically sensitive to high temperature, a higher relative biomass growth was still observed under long-term high temperature and osmotic stresses. Further investigation found that reactive oxygen species (ROS) homeostasis of transgenic plants was significantly affected, being ~50 % reduction of H2O2 level relative to wild-type plants. Gene transcription including ROS responsive genes was overall attenuated in transgenic plants, being more significant at normal temperature than at high temperature. In addition, ascorbate peroxidase (APX) activity was increased nearly twofolds in transgenic plants as compared to wild-type control. It may be inferred that ectopic NfFeSOD overexpression gives rise to a substantial increase of APX activity and leads to a sharp reduction of H2O2 level, thus impairing basal ROS signaling and plant growth. Specific genetic background of S. alfredii may be responsible for this sharp reduction of H2O2 level induced by NfFeSOD overexpression. S. alfredii plant has acclimated to elevated levels of ROS induced by heavy metals in native habitats and should require high ROS levels for basal signaling. We thus suppose that a sustained disturbance of high basal ROS signaling in metal hyperaccumulators may instead incur very sensitive response and thus result in profound growth impairments.

Imatinib Mesylate Versus Allogeneic Hematopoietic Stem Cell Transplantation for Patients with Chronic Myelogenous Leukemia

Zhang, Gui-Fang,Zhou, Min,Bao, Xie-Bing,Qiu, Hui-Ying,Li, Zheng,Xue, Sheng-Li Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.9

Purpose: To compare the relative merits of imatinib and allogeneic hematopoietic stem cell transplantation (allo-HSCT) for chronic myelogenous leukemia (CML). Materials and Methods: This cohort study was designed to compare the outcomes of imatinib (n=292) versus allo-HSCT (n=141) for CML, the clinical data of these patients being retrospectively analyzed so as to compare the event free survival (EFS) and overall survival (OS) between these two groups with patients in the chronic phase (CP) and advanced phases, including accelerate (AP) and blast phases (BP). Results: (1) Patients treated with imatinib (278 in the CP) demonstrated superior EFS, OS, 5-year EFS and 5-year OS rates of 88.5% versus 70.0% (P<0.05), 93.2% versus 80.0% (P<0.05), 84% versus 75.0% (P<0.05) and 92% versus 79.0% (P<0.05), respectively, to those treated with allo-HSCT (120 patients in the CP). (2) Both treatments resulted in similar survival, with EFS and OS rates of 42.9% versus 47.6% (P>0.05), 42.9% versus 57.1% (P> 0.05), respectively, for imatinib (14 patients in the AP and BP) and allo-HSCT (21 patients in the AP and BP). Conclusions: Imatinib confers significant survival advantage (EFS and OS) for CML patients with CP compared with allo-HSCT treatment. However, the outcomes are equally good with both treatments in AP and BP patients.

Induction of Apoptosis by IGFBP3 Overexpression in Hepatocellular Carcinoma Cells

Han, Jian-Jun,Xue, De-Wen,Han, Qiu-Rong,Liang, Xiao-Hong,Xie, Li,Li, Sheng,Wu, Hui-Yong,Song, Bao Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Background: The insulin-like growth factor (IGF) system comprises a group of proteins that play key roles in regulating cell growth, differentiation, and apoptosis in a variety of cellular systems. The aim of this study was to investigate the role of insulin-like growth factor binding protein 3 (IGFBP3) in hepatocellular carcinoma. Materials and Methods: Expression of IGF2, IGFBP3, and PTEN was analyzed by qRT-PCR. Lentivirus vectors were used to overexpress IGFBP3 in hepatocellular carcinoma cell (HCC) lines. The effect of IGFBP3 on proliferation was investigated by MTT and colony formation assays. Results: Expression of IGF2, IGFBP3, and PTEN in several HCC cell lines was lower than in normal cell lines. After 5-aza-2'-deoxycytidine/trichostatin A treatment, significant demethylation of the promoter region of IGFBP3 was observed in HCC cells. Overexpression of IGFBP3 induced apoptosis and reduced colony formation in HUH7 cells. Conclusions: Expression of IGF2, IGFBP3, and PTEN in several HCC cell lines was lower than in normal cell lines. After 5-aza-2'-deoxycytidine/trichostatin A treatment, significant demethylation of the promoter region of IGFBP3 was observed in HCC cells. Overexpression of IGFBP3 induced apoptosis and reduced colony formation in HUH7 cells.

Cues of intraguild predators (Harmonia axyridis) and different temperatures alter foraging and oviposition strategies of the parasitoid Aphidius gifuensis

Yu Xing-Lin,Feng Yi,Liu Tong-Xian,Qiu Bao-Li 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.2

Organisms live in complex systems where they simultaneously balance responses to multiple factors. Insects are dealing with indirect pressures from predators under the influence of temperature. Currently, little is known about how they balance these factors. Under laboratory conditions, we investigated the effects of the predator Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) cues and temperature (23, 28, and 33 ◦ C) on the foraging and oviposition behavior of the parasitoid Aphidius gifuensis Ashmead (Hymenoptera: Braconidae) using the aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) as a host. In all trials, the frequency and duration of stinging, walking, or stationary behavior of A. gifuensis were not influenced by H. axyridis cues. However, in trials with predator cues, A. gifuensis produced less offspring than trials without predator cues. On the other hand, the frequency of A. gifuensis stinging, walking, or stationary behavior, and the number of A. gifuensis larvae increased with rising temperature. Specially, when the predator cues were present, parasitoid responded to rising tem peratures by increasing frequency of each behavior and an increase in offspring number. Our findings indicate that A. gifuensis might show flexible foraging and oviposition behavior in response to H. axyridis associated cues and different temperatures. Thus, the effects of both temperature and H. axyridis cues should be considered when assessing the foraging outcomes of A. gifuensis prior to combining these two enemies in aphid management practice.