Stress Redistribution of Headed Stud Connectors Subjected to Constant Shear Force

Rong Liu,Zhiqiang Feng,Hengda Ye,Yuqing Liu 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.2

In order to evaluate the stress concentration of stud shear connectors considering creep effect of concrete, finite element analysis of the push-out specimen is carried out. The rate of creep method is used in the solid model to reflect the creep property of concrete. Local bearing stress and splitting stress of concrete are analyzed. The stress concentration of steel beam and stud near the weld toe are obtained. Results show that owing to the creep effect of concrete, the local stresses of the stud are redistributed, even under constant shear force. The stress concentration factor (SCF) of concrete bearing stress in front of the weld collar decreases by about 52%, while the bending deformation of the stud increases due to the stress redistribution given 10 years of creep time. SCF at the weld toe of steel beam increases about 1.5 times of short-term, and SCF of stud shank increases about 3 times. The stress concentration at the root of studs become more obvious under constant shear force due to concrete creep, which is adverse for the long-term behavior of studs in the normal service stage.

K-Charmonium Dissociation Cross Sections and Charmonium Dissociation Rates in Hadronic Matter

Feng-Rong Liu,Shi-Tao Ji,Xiao-Ming Xu 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.4

K-charmonium dissociation reactions in hadronic matter are studied in the Born approximation, in the quark-interchange mechanism, and with a temperature-dependent quark potential. We obtain the temperature dependence of the unpolarized cross sections for the reactions KJ/ ! ¯D D+ s , ¯D D+ s , ¯DD+ s , and ¯DD+ s ; K 0 ! ¯DD+ s , ¯DD+ s , ¯DD+ s , and ¯DD+ s ; Kc ! ¯DD+ s , ¯DD+ s , ¯D D+ s , and ¯D D+ s . We use the cross sections for charmonium dissociation in collisions with pions, mesons, kaons, vector kaons, and mesons to calculate the dissociation rates of charmonium with five types of mesons. Because of the temperature dependence of the meson masses, dissociation cross sections, and meson distribution functions, the charmonium dissociation rates generally increase with increasing temperature and decrease with increasing charmonium momentum from 2.2 GeV/c. We find that the first derivative of the dissociation rate with respect to the charmonium momentum is zero when the charmonium is at rest. While the + 0 and the + c dissociation reactions can be neglected, the J/ , 0, and c dissociations are caused by collisions with pions, mesons, kaons, vector kaons, and mesons.

Molecular Cloning and Function Analysis of an Anthocyanidin Synthase Gene from Ginkgo biloba, and Its Expression in Abiotic Stress Responses

Feng Xu,Hua Cheng,Rong Cai,Lin Ling Li,Jie Chang,Jun Zhu,Feng Xia Zhang,Liu Ji Chen,Yan Wang,Shu Han Cheng,Shui Yuan Cheng 한국분자세포생물학회 2008 Molecules and cells Vol.26 No.6

Anthocyanidin synthase (ANS, leucoanthocyanidin oxygenase), a 2-oxoglutarate iron-dependent oxygenase, catalyzed the penultimate step in the biosynthesis of the anthocyanin class of flavonoids, from the colorless leucoanthocyanidins to the colored anthocyanidins. The full-length cDNA and genomic DNA sequences of ANS gene (designated as GbANS) were isolated from Ginkgo biloba for the first time. The full-length cDNA of GbANS contained a 1062-bp open reading frame (ORF) encoding a 354-amino-acid protein. The genomic DNA analysis showed that GbANS gene had three exons and two introns. The deduced GbANS protein showed high identities to other plant ANSs. The conserved amino acids (H-X-D) ligating ferrous iron and residues (R-X-S) participating in 2-oxoglutarate binding were found in GbANS at the similar positions like other ANSs. Southern blot analysis indicated that GbANS belonged to a multi-gene family. The expression analysis by real-time PCR showed that GbANS expressed in a tissue-specific manner in G. biloba. GbANS was also found to be up-regulated by all of the six tested abiotic stresses, UV-B, abscisic acid, sucrose, salicylic acid, cold and ethylene, consistent with the promoter region analysis of GbANS. The recombinant protein was successfully expressed in E. coli strain with pET-28a vector. The in vitro enzyme activity assay by HPLC indicated that recombinant GbANS protein could catalyze the formation the cyanidin from leucocyanidin and conversion of dihydroquercetin to quercetin, suggesting GbANS is a bifunctional enzyme within the anthocyanidin and flavonol biosynthetic pathway.

Acupuncture reduces nicotine-induced norepinephrine release in the hypothalamus via the solitary NMDA receptor/NOS pathway

Liu, Hong Feng,Zhao, ZhengLin,Zhang, Jie,Wu, Yi Yan,Jiao, Yu,Wu, Tong,Kim, Sang Chan,Lee, Bong Hyo,Fan, Yu,Lee, Chul Won,Kim, Young Woo,Yang, Chae Ha,Zhu, Xiao Dong,Zhao, Rong Jie Elsevier 2019 Neuroscience Letters Vol.705 No.-

<P><B>Abstract</B></P> <P>Noradrenergic projections from the nucleus tractus solitarius (NTS) to the hypothalamic paraventricular nucleus (PVN) are involved in nicotine (Nic) dependence. Nic induces hypothalamic norepinephrine (NE) release through <I>N</I>-methyl-<SMALL>D</SMALL>-aspartate receptors (NMDARs) and nitric oxide in the NTS. However, acupuncture attenuates Nic withdrawal-induced anxiety. Therefore, this study investigated the effects of acupuncture on Nic-induced hypothalamic NE release. Rats received an intravenous infusion of Nic (90 μg/kg, over 60 s) and extracellular NE levels in the PVN were determined by in vivo microdialysis. Immediately after Nic administration, the rats were bilaterally treated with acupuncture at acupoint HT7 (Shen-Men) or PC6 (Nei-Guan), or a non-acupoint (tail) for 60 s. Acupuncture at HT7, but not at PC6 or the tail, significantly reduced Nic-induced NE release. However, this was abolished by a post-acupuncture infusion of either NMDA or sodium nitroprusside into the NTS. Additionally, acupuncture at HT7, but not the control points, prevented Nic-induced plasma corticosterone secretion and inhibited Nic-induced increases in the phosphorylation of neuronal nitric oxide synthase (nNOS) and endothelial NOS in the NTS. These findings suggest that acupuncture at HT7 reduces Nic-induced NE release in the PVN via inhibition of the solitary NMDAR/NOS pathway.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Acupuncture inhibited nicotine-induced hypothalamic norepinephrine release. </LI> <LI> Acupuncture diminished nicotine-induced plasma corticosterone secretion. </LI> <LI> Acupuncture reversed nicotine-induced phosphorylation of solitary nNOS and eNOS. </LI> <LI> NMDA abolished acupunctural effects on nicotine-induced norepinephrine release. </LI> <LI> NO abolished acupunctural effects on nicotine-induced norepinephrine release. </LI> </UL> </P>

General Situation of Ginseng Cultivation and Research in China

(Rong Sheng Wang),(Hao Zhe Lian),(Feng Yang Liu) 고려인삼학회 1990 Proceedings of International Symposium on Korean G Vol.- No.-

Senescence as A Consequence of Ginsenoside Rg₁ Response on K562 Human Leukemia Cell Line

Liu, Jun,Cai, Shi-Zhong,Zhou, Yue,Zhang, Xian-Ping,Liu, Dian-Feng,Jiang, Rong,Wang, Ya-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.12

Aims and Background: Traditional chemotherapy strategies for human leukemia commonly use drugs based on cytotoxicity to eradicate cancer cells. One predicament is that substantial damage to normal tissues is likely to occur in the course of standard treatments. Obviously, it is urgent to explore therapies that can effectively eliminate malignant cells without affecting normal cells. Our previous studies indicated that ginsenoside $Rg_1$ ($Rg_1$), a major active pharmacological ingredient of ginseng, could delay normal hematopoietic stem cell senescence. However, whether $Rg_1$ can induce cancer cell senescence is still unclear. Methods: In the current study, human leukemia K562 cells were subjected to $Rg_1$ exposure. The optimal drug concentration and duration with K562 cells was obtained by MTT colorimetric test. Effects of $Rg_1$ on cell cycle were analyzed using flow cytometry and by SA-${\beta}$-Gal staining. Colony-forming ability was measured by colony-assay. Telomere lengths were assessed by Southern blotting and expression of senescence-associated proteins P21, P16 and RB by Western blotting. Ultrastructural morphology changes were observed by transmission electron microscopy. Results: K562 cells demonstrated a maximum proliferation inhibition rate with an $Rg_1$ concentration of $20{\mu}\;mol{\cdot}L^{-1}$ for 48h, the cells exhibiting dramatic morphological alterations including an enlarged and flat cellular morphology, larger mitochondria and increased number of lysosomes. Senescence associated-${\beta}$-galactosidase (SA-${\beta}$-Gal) activity was increased. K562 cells also had decreased ability for colony formation, and shortened telomere length as well as reduction of proliferating potential and arrestin $G_2$/M phase after $Rg_1$ interaction. The senescence associated proteins P21, P16 and RB were significantly up-regulated. Conclusion: Ginsenoside $Rg_1$ can induce a state of senescence in human leukemia K562 cells, which is associated with p21-Rb and p16-Rb pathways.

Roles of Signaling Pathways in the Epithelial-Mesenchymal Transition in Cancer

Liu, Xia,Yun, Fen,Shi, Lin,Li, Zhe-Hai,Luo, Nian-Rong,Jia, Yong-Feng Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

The epithelial-mesenchymal transition (EMT) is a cellular process though which an epithelial phenotype can be converted into a phenotype of mesenchymal cells. Under physiological conditions EMT is important for embryogenesis, organ development, wound repair and tissue remodeling. However, EMT may also be activated under pathologic conditions, especially in carcinogenesis and metastatic progression. Major signaling pathways involved in EMT include transforming growth factor ${\beta}(TGF-{\beta})$, Wnt, Notch, Hedgehog and other signaling pathways. These pathways are related to several transcription factors, including Twist, Smads and zinc finger proteins snail and slug. These interact with each other to provide crosstalk between the relevant signaling pathways. This review lays emphasis on studying the relationship between EMT and signaling pathways in carcinogenesis and metastatic progression.

Neuron Discharge and c-Fos Expression in the Nucleus of the Solitary Tract Following Electroacupuncture at Acupoints of the Yangming Stomach Meridian of Foot

Jun-Feng He,Jie Yan,Jiang-Shan Li,Jian-Hua Liu,Chao Wang,Xiao-Rong Chang,Ya-Ting Qu 사단법인약침학회 2013 Journal of Acupuncture & Meridian Studies Vol.6 No.2

The nucleus of the solitary tract (nucleus tractus solitarii; NTS) is a primary center for both visceral afferents and somatic afferents. Previous experiments have demonstrated that the NTS is closely connected to the stomach and acupoints in the Yangming Stomach Meridian of Foot (ST Meridian). In this study, extracellular recording and immunochemistry methods were used to analyze the discharge of neurons and c-Fos protein expression in the NTS following acupuncture at different acupoints and a nonacupoint. A total of 104 discharging neurons were detected in the NTS of 52 rats, of which 86 provided complete data. After acupuncture at Sibai (ST 2), Zusanli (ST 36), Neiting (ST 44), Quanliao (SI 18), and the nonacupoint, the neuron response rate in the NTS was 65.12%, 51.16%, 46.51%, 34.88% and 31.40% respectively. For neuron response rate, there was a significant difference among Sibai (ST 2), Zusanli (ST 36), Neiting (ST 44), Quanliao (SI 18), and the nonacupoint (p < 0.01 or p < 0.05). In the other 48 rats, the number of c-Fos immunoreactive neurons in the NTS by electroacupuncture (EA) at Sibai (ST 2) group was significantly higher than that EA at other acupoints and the nonacupoint (p < 0.05 or p < 0.01). EA at both Zusanli (ST 36) and Neiting (ST 44) increased c-Fos immunoreactive neurons significantly over EA at Quanliao (SI 18) and the nonacupoint (p < 0.05 or p < 0.01), while there was no difference between EA at Quanliao (SI 18) and the nonacupoint group (p > 0.05). The experiments demonstrated that the afferent convergence in NTS are different by body surface points stimulus, which suggests that the NTS might be a primary center in the central nervous system receiving acupoints stimulus from the ST Meridian.

An investigation on tribological properties of the chemically capped zinc borate(ZB)/MoS2 nanocomposites in oil

Pei-Rong Wu,Yu-Mei Feng,Ting Ge,Ying-Chao Kong,Zhan-Sheng Ma,Zan Liu,Zhi-Lin Cheng 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.63 No.-

The surface of self-made MoS2 nanosheets with five-layer structure was successively decorated by zinc borate (ZB) nanoparticles with coordination enhancement on the tribological performance and modified by three types of modifiers for improving dispersivity in oil. A series of characterizations determined the chemical modification and composite structure of the ZB/MoS2 nanocomposites. The tribological properties of the chemically capped ZB/MoS2 nanocomposites were extensively examined on a ball-on-ball wear tester. The average friction coefficient and average wear scar diameter of the OA-ZB/MoS2-based oil dropped by about 25.2% and 52.2%, and furthermore the extreme pressure performance increased by about 15.2% compared to oil.

Post-diagnosis Soy Food Intake and Breast Cancer Survival: A Meta-analysis of Cohort Studies

Chi, Feng,Wu, Rong,Zeng, Yue-Can,Xing, Rui,Liu, Yang,Xu, Zhao-Guo Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4

Background and Objectives: Data on associations between soy food intake after cancer diagnosis with breast cancer survival are conflicting, so we conducted this meta-analysis for more accurate evaluation. Methods: Comprehensive searches were conducted to find cohort studies of the relationship between soy food intake after cancer diagnosis and breast cancer survival. Data were analyzed with comprehensive meta-analysis software. Results: Five cohort studies (11,206 patients) were included. Pooling all comparisons, soy food intake after diagnosis was associated with reduced mortality (HR 0.85, 95%CI 0.77 0.93) and recurrence (HR 0.79, 95%CI 0.72 0.87). Pooling the comparisons of highest vs. lowest dose, soy food intake after diagnosis was again associated with reduced mortality (HR 0.84, 95%CI 0.71 0.99) and recurrence (HR 0.74, 95%CI 0.64 0.85). Subgroup analysis of ER status showed that soy food intake was associated with reduced mortality in both ER negative (highest vs. lowest: HR 0.75, 95%CI 0.64 0.88) and ER positive patients (highest vs. lowest: HR 0.72, 95%CI 0.61 0.84), and both premenopausal (highest vs. lowest: HR 0.78, 95%CI 0.69 0.88) and postmenopausal patients (highest vs. lowest: HR 0.81, 95%CI 0.73 0.91). In additioin, soy food intake was associated with reduced recurrence in ER negative (highest vs. lowest: HR 0.64, 95%CI 0.44 0.94) and ER+/PR+ (highest vs. lowest: HR 0.65, 95%CI 0.49 0.86), and postmenopausal patients (highest vs. lowest: HR 0.67, 95%CI 0.56 0.80). Conclusion: Our meta-analysis showed that soy food intake might be associated with better survival, especially for ER negative, ER+/PR+, and postmenopausal patients.