CFD ANALYSIS AND REDESIGN OF THE FRANCIS TURBINE WITH LARGE HEAD VARIATION

GUO PENGCHENG,LUO XINGQI,LIU SHENGZHU 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

Influence of tip clearance on pressure fluctuations in an axial flow pump

Jianjun Feng,Xingqi Luo,Pengcheng Guo,Guangkuan Wu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.4

Rotor-stator interaction in axial pumps can produce pressure fluctuations and further vibrations even damage to the pump system in some extreme case. In this paper, the influence of tip clearance on pressure fluctuations in an axial flow water pump has been investigated by numerical method. Three-dimensional unsteady flow in the axial flow water pump has been simulated with different tip clearances between the impeller blade tip and the casing wall. In addition to monitoring pressure fluctuations at some typical points, a new method based on pressure statistics was proposed to determine pressure fluctuations at all grid nodes inside the whole pump. The comparison shows that the existence of impeller tip clearance magnifies the pressure fluctuations in the impeller region, from the hub to shroud. However, the effect on pressure fluctuation in the diffuser region is not evident. Furthermore, the tip clearance vortex has also been examined under different tip clearances.

A Resting-state Functional Magnetic Resonance Imaging Study of Whole-brain Functional Connectivity of Voxel Levels in Patients With Irritable Bowel Syndrome With Depressive Symptoms

( Jie Li ),( Ping He ),( Xingqi Lu ),( Yun Guo ),( Min Liu ),( Guoxiong Li ),( Jianping Ding ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2021 Journal of Neurogastroenterology and Motility (JNM Vol.27 No.2

Background/Aims Depressive symptom is one of the most common symptoms in patients with irritable bowel syndrome (IBS), but its pathogenetic mechanisms remain unclear. As a voxel-level graph theory analysis method, degree centrality (DC) can provide a new perspective for exploring the abnormalities of whole-brain functional network of IBS with depressive symptoms (DEP-IBS). Methods DC, voxel-wise image and clinical symptoms correlation and seed-based functional connectivity (FC) analyses were performed in 28 DEP-IBS patients, 21 IBS without depressive symptoms (nDEP-IBS) patients and 36 matched healthy controls (HC) to reveal the abnormalities of whole brain FC in DEP-IBS. Results Compared to nDEP-IBS patients and HC, DEP-IBS patients showed significant decrease of DC in the left insula and increase of DC in the left precentral gyrus. The DC’s z-scores of the left insula negatively correlated with depression severity in DEP-IBS patients. Compared to nDEP-IBS patients, DEP-IBS patients showed increased left insula-related FC in the left inferior parietal lobule and right inferior occipital gyrus, and decreased left insula-related FC in the left precentral gyrus, right supplementary motor area (SMA), and postcentral gyrus. In DEP-IBS patients, abstracted clusters’ mean FC in the right SMA negatively correlated with depressive symptoms. Conclusions DEP-IBS patients have abnormal FC in brain regions associated with the fronto-limbic and sensorimotor networks, especially insula and SMA, which explains the vicious circle between negative emotion and gastrointestinal symptoms in IBS. Identification of such alterations may facilitate earlier and more accurate diagnosis of depression in IBS, and development of effective treatment strategies. (J Neurogastroenterol Motil 2021;27:248-256)

Conserved Sequences of Replicase Gene-Mediated Resistance to Potyvirus through RNA Silencing

Li Xu,YunZhi Song,JunHua Zhu,XingQi Guo,ChangXiang Zhu,FuJiang Wen 한국식물학회 2009 Journal of Plant Biology Vol.52 No.6

Nuclear inclusion protein b (NIb) genes of three Potato virus Y isolates PVY-SD1 (O strain), PVY-SD4 (N strain), PVY-SD5 (NTN strain), and Tobacco etch virus isolate TEV-SD1 in Shandong Province were cloned and sequenced. Sequence analysis showed that the sequence homology of the entire NIb gene among the four viruses ranged from 65% to 95%. Hairpin RNA (hpRNA) constructs were designed based on five conserved regions derived from PVY-SD1 and introduced into tobacco plants. After asexual propagation, the transgenic plants were analyzed for resistance to PVY-SD1, PVY-SD4, PVY-SD5, and TEV-SD1. We obtained resistance ratios of 26.2%, 22.7%, 36.4%, 20.3%, and 21.7% to PVY-SD1. When inoculated with the PVY-SD5 virus, the transgenic plants had resistance ratios ranging from 2.4% to 15.9%, but no resistance at all to the other viruses, PVY-SD4 and TEV-SD1. No correlation was found between resistance of transgenic plants and the transgene copy numbers. Northern blot and small interfering RNA (siRNA) analysis demonstrated that the resistance was attributable to RNA silencing. Genetic analysis demonstrated that virus resistance was stably inherited in progeny T1 and T2. These results indicate that the siRNA molecules against conserved regions can confer virus resistance but are restricted to viruses with more than 90% sequence homology.

Molecular characterization and immunohistochemical localization of a mitogen-activated protein kinase, Accp38b, from Apis cerana cerana

Zhang, Liang,Meng, Fei,Li, Yuzhen,Kang, Mingjiang,Guo, Xingqi,Xu, Baohua Korean Society for Biochemistry and Molecular Biol 2012 BMB Reports Vol.45 No.5

The p38 mitogen-activated protein kinase (MAPK) is involved in various processes, including stress responses, development, and differentiation. However, little information on p38 MAPK in insects is available. In this study, a p38 MAPK gene, $Accp38b$, was isolated from $Apis$ $cerana$ $cerana$ and characterized. The quantitative real-time PCR (Q-PCR) analysis revealed that $Accp38b$ was induced by multiple stressors. Notably, the expression of $Accp38b$ was relatively higher in the pupae phase than in other developmental phases. During the pupae phase, Accp38b expression was higher in the thorax than in the head and abdomen and higher in the fat body than in the muscle and midgut. Immunohistochemisty showed significant positive staining of Accp38b in sections from the brain, eyes, fat body, and midgut of $A.$ $cerana$ $cerana$. These results suggest that Accp38b may play a crucial role in stress responses and have multiple aspects function during development.

Molecular Characterization of a Transient Expression Gene Encoding for 1-Aminocyclopropane-1-carboxylate Synthase in Cotton (Gossypium hirsutum L.)

Wang, Xia,Zhang, Ying,Zhang, Jiedao,Cheng, Cheng,Guo, Xingqi Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.5

Ethylene performs an important function in plant growth and development. 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS), the key enzyme involved in ethylene biosynthesis, has been the focus of most ethylene studies. Here, a cotton ACS gene referred to as Gossypium hirsutum ACS1 (GhACS1), was isolated. The full-length cDNA of GhACS1 encodes for a 476-amino acid protein which harbors seven conserved regions, 11 invariant amino acid residues, and the PLP binding active site, all of which characterize ACC synthases. Alignment analysis showed that GhACS1 shared a high degree of identity with other known ACC synthases from different species. Two introns were detected in the genomic DNA sequence, and the results of Southern blot analysis suggested that there might be a multi-gene family encoding for ACC synthase in cotton. From the phylogenetic tree constructed with 24 different kinds of ACC synthases, we determined that GhACS1 falls into group II, and was closely associated with the wound-inducible ACS of citrus. The analysis of the 5' flanking region of GhACS1 revealed a group of putative cis-acting elements. The results of expression analysis showed that GhACS1 displayed its transient expression nature after wounding, abscisic acid (ABA), and $CuCl_2$ treatments. These results indicate that GhACS1, which was transiently expressed in response to certain stimuli, may be involved in the production of ethylene for the transmission of stress signals.

A Novel MAP Kinase Gene in Cotton (Gossypium hirsutum L.), GhMAPK, is Involved in Response to Diverse Environmental Stresses

Wang, Meimei,Zhang, Ying,Wang, Jian,Wu, Xiaoliang,Guo, Xingqi Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.3

The mitogen-activated protein kinase (MAPK) cascade is one of the major and evolutionally conserved signaling pathways and plays pivotal role in the regulation of stress and developmental signals in plants. Here, a novel gene, termed Gossypium hirsutum MAPK (GhMAPK), was isolated from cotton. The full-length cDNA of GhMAPK encodes for a 372 amino acid protein that contains all 11 of the MAPK conserved subdomains and the phosphorylationactivation motif, TEY. Amino acid sequence alignment revealed that GhMAPK shared high identity with group-C MAPK in plants and showed 83~89% similarities with MAPKs from Arabidopsis, apricot, pea, petunia, and tobacco. Southern blot analysis indicated that the GhMAPK belonged to a multygene family in cotton. Two introns were found within the region of genomic sequence. Northern blot analysis revealed that the transcripts of GhMAPK accumulated markedly when the cotton seedlings were subjected to various abiotic stimuli such as wounding, cold (4$^{\circ}C$), or salinity stress; Furthermore, GhMAPK was upregulated by the exogenous signaling molecules, such as salicylic acid (SA) and hydrogen peroxide ($H_2O_2C$), as well as pathogen attacks. These results indicate that the GhMAPK, which has a high degree of identity with group-C plant MAPKs, may also play an important role in response to environmental stresses.

Influence of Peanut Cultivars and Environmental Conditions on the Diversity and Community Composition of Pod Rot Soil Fungi in China

Wang, Mian,Chen, Mingna,Yang, Zhen,Chen, Na,Chi, Xiaoyuan,Pan, Lijuan,Wang, Tong,Yu, Shanlin,Guo, Xingqi The Korean Society of Mycology 2017 Mycobiology Vol.45 No.4

Peanut yield and quality are seriously affected by pod rot pathogens worldwide, especially in China in recent years. The goals of this study are to analyze the structure of fungal communities of peanut pod rot in soil in three peanut cultivars and the correlation of pod rot with environmental variables using 454 pyrosequencing. A total of 46,723 internal transcribed spacer high-quality sequences were obtained and grouped into 1,706 operational taxonomic units at the 97% similarity cut-off level. The coverage, rank abundance, and the Chao 1 and Shannon diversity indices of the operational taxonomic units were analyzed. Members of the phylum Ascomycota were dominant, such as Fusarium, Chaetomium, Alternaria, and Sordariomycetes, followed by Basidiomycota. The results of the heatmap and redundancy analysis revealed significant variation in the composition of the fungal community among the three cultivar samples. The environmental conditions in different peanut cultivars may also influence on the structure of the fungal community. The results of this study suggest that the causal agent of peanut pod rot may be more complex, and cultivars and environmental conditions are both important contributors to the community structure of peanut pod rot fungi.

Influence of Peanut Cultivars and Environmental Conditions on the Diversity and Community Composition of Pod Rot Soil Fungi in China

( Mian Wang ),( Mingna Chen ),( Zhen Yang ),( Na Chen ),( Xiaoyuan Chi ),( Lijuan Pan ),( Tong Wang ),( Shanlin Yu ),( Xingqi Guo ) 한국균학회 2017 Mycobiology Vol.45 No.4

Peanut yield and quality are seriously affected by pod rot pathogens worldwide, especially in China in recent years. The goals of this study are to analyze the structure of fungal communities of peanut pod rot in soil in three peanut cultivars and the correlation of pod rot with environmental variables using 454 pyrosequencing. A total of 46,723 internal transcribed spacer high-quality sequences were obtained and grouped into 1,706 operational taxonomic units at the 97% similarity cut-off level. The coverage, rank abundance, and the Chao 1 and Shannon diversity indices of the operational taxonomic units were analyzed. Members of the phylum Ascomycota were dominant, such as Fusarium, Chaetomium, Alternaria, and Sordariomycetes, followed by Basidiomycota. The results of the heatmap and redundancy analysis revealed significant variation in the composition of the fungal community among the three cultivar samples. The environmental conditions in different peanut cultivars may also influence on the structure of the fungal community. The results of this study suggest that the causal agent of peanut pod rot may be more complex, and cultivars and environmental conditions are both important contributors to the community structure of peanut pod rot fungi.