R-type Calcium Channel Isoform in Rat Dorsal Root Ganglion Neurons

Zhi Fang,황재홍,김종수,정성준,오석배 대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.1

R-type Cav2.3 high voltage-activated Ca2+ channels in peripheral sensory neurons contribute to pain transmission. Recently we have demonstrated that, among the six Cav2.3 isoforms (Cav2.3a∼Cav2.3e), the Cav2.3e isoform is primarily expressed in trigeminal ganglion (TG) nociceptive neurons. In the present study, we further investigated expression patterns of Cav2.3 isoforms in the dorsal root ganglion (DRG) neurons. As in TG neurons, whole tissue RT-PCR analyses revealed the presence of two isoforms, Cav2.3a and Cav2.3e, in DRG neurons. Single-cell RT-PCR detected the expression of Cav2.3e mRNA in 20% (n=14/70) of DRG neurons, relative to Cav2.3a expression in 2.8% (n=2/70) of DRG neurons. Cav2.3e mRNA was mainly detected in small-sized neurons (n=12/14), but in only a few medium-sized neurons (n=2/14) and not in large-sized neurons, indicating the prominence of Cav2.3e in nociceptive DRG neurons. Moreover, Cav2.3e was preferentially expressed in tyrosine-kinase A (trkA)-positive, isolectin B4 (IB4)-negative and transient receptor potential vanilloid 1 (TRPV1)-positive neurons. These results suggest that Cav2.3e may be the main R-type Ca2+ channel isoform in nociceptive DRG neurons and thereby a potential target for pain treatment, not only in the trigeminal system but also in the spinal system.

Phylogenetic Analysis on the Bacteria Producing Non-Volatile Fungistatic Substances

ZhiFang Li,ChangSong Zou,YueQiu He,MingHe Mo,KeQin Zhang 한국미생물학회 2008 The journal of microbiology Vol.46 No.3

This study characterized the soil bacteria producing non-volatile fungistatic substances. Among the 2,100 colonies of soil bacteria randomly isolated from seven agricultural soil samples, 518 isolates (24.67% of total) showed fungistatic activity toward nematophagous fungi Paecilomyces lilacinus and Trichoderma viride by producing non-volatile substances. A phylogenetic analysis based on amplified ribosomal DNA restriction analysis (ARDRA) and 16S rDNA sequence placed the 518 bacteria in three groups of the domain Bacteria: Actinomycetales, Bacillales, and Gammaproteobacteria. Three genera, Arthrobacter, Bacillus, and Pseudomonas, were the most frequently encountered groups.

Effect of MgO on migration and distribution of chromium in stainless-steel slag glass–ceramics and glass properties

Zhifang Tong,Congcong Xu,Jiaxing Wang,Zhiheng Jia 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.1

Herein, stainless-steel slag was used to prepare glass–ceramics. The effects of the MgO content on the occurrence, distributionstate, and migration behavior of Cr in glass–ceramics as well as glass properties were systematically studied. Results revealedthat in the nucleation stage, the number of Cr-spinel (Cr spinel) nanocrystals initially increased and then decreased with theincreasing MgO content. In the crystallization stage, the diopside crystal phase considered Cr-spinel nanocrystals asheterogeneous nuclei, which gradually nucleated and grew. Transmission electron microscopy and X-ray photoelectronspectroscopy analyses showed that part of Cr in the spinel migrated into the diopside lattice and some other parts remainedin the Cr spinel wrapped by the diopside. Cr in the glass phase also diffused and migrated into the diopside lattice with theformation of diopside crystals. When the MgO content was 12.3 wt.%, 97.33 wt.% of the total amount of Cr was observedin the diopside crystal phase and the leaching concentration of Cr in the glass–ceramics was only 0.006 mg/L. The compressivestrength of the glass–ceramics was 261.7 MPa, and the Vickers hardness was 1007.7 HV. The research results providetheoretical and technical support for strengthening Cr fixation and realizing harmless and high-value utilization of stainlesssteelslag.

Optimization of long span portal frames using spatially distributed surrogates

Zhifang Zhang,Jingwen Pan,Jiyang Fu,Hemant Kumar Singh,Yong-Lin Pi,Jiurong Wu,Rui Rao 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.24 No.2

This paper presents optimization of a long-span portal steel frame under dynamic wind loads using a surrogate-assisted evolutionary algorithm. Long-span portal steel frames are often used in low-rise industrial and commercial buildings. The structure needs be able to resist the wind loads, and at the same time it should be as light as possible in order to be cost-effective. In this work, numerical model of a portal steel frame is constructed using structural analysis program (SAP2000), with the web-heights at five locations of I-sections of the columns and rafters as the decision variables. In order to evaluate the performance of a given design under dynamic wind loading, the equivalent static wind load (ESWL) is obtained from a database of wind pressures measured in wind tunnel tests. A modified formulation of the problem compared to the one available in the literature is also presented, considering additional design constraints for practicality. Evolutionary algorithms (EA) are often used to solve such non-linear, black-box problems, but when each design evaluation is computationally expensive (e.g., in this case a SAP2000 simulation), the time taken for optimization using EAs becomes untenable. To overcome this challenge, we employ a surrogate-assisted evolutionary algorithm (SAEA) to expedite the convergence towards the optimum design. The presented SAEA uses multiple spatially distributed surrogate models to approximate the simulations more accurately in lieu of commonly used single global surrogate models. Through rigorous numerical experiments, improvements in results and time savings obtained using SAEA over EA are demonstrated.

Fumigant Activity of Volatiles from Streptomyces alboflavus TD-1 against Fusarium moniliforme Sheldon

Zhifang Wang,Changlu Wang,Fengjuan Li,Zhenjing Li,Mianhua Chen,Yurong Wang,Xi Qiao,Hong Zhang 한국미생물학회 2013 The journal of microbiology Vol.51 No.4

The fumigant activity of volatiles generated by Streptomyces alboflavus TD-1 against Fusarium moniliforme Sheldon was investigated. The results showed that the mycelial growth,sporulation, and spore germination of F. moniliforme were significantly suppressed, and that membrane permeability was disrupted in the presence of the volatiles. Gas chromatography-mass Spectrometry analysis revealed 31 kinds of volatile organic compound from the volatiles. Among them,two earthy-smelling substances, namely, 2-methylisoborneol (50.97%) and trans-1,10-dimethyl-trans-9-decalinol (3.10%)were found. The most abundant compound, 2-methylisoborneol,exhibited inhibitory activity against F. moniliforme by fumigation. All these results suggested that S. alboflavus TD-1 can be a promising starter for the inhibition of F. moniliforme through fumigant action.

Meshing characteristics of spur gear pairs with tooth modification under different assembly errors and sensitivity analysis for impact factors

Zhifang Zhao,Yang Yang,Hui Ma,Haixu Wang,Hongxu Tian,Chenyi Han 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.1

Assembly errors may change contact state of gear pairs, then induce failure and vibration. To reveal the effects of assembly errors and tooth modification on the meshing characteristics, the loaded tooth contact analysis (LTCA) is conducted through an improved algorithm. The time-varying meshing stiffness (TVMS), static transmission error (STE) and contact stress (CS) are calculated considering assembly errors and tooth modification. Then, sensitivity of meshing characteristics to coupling assembly errors are investigated based on the design of orthogonal experiment (DOE). The meshing characteristic analysis results show that assembly errors have a significant effect on mesh characteristics of the gear pair. The results of sensitivity analysis indicate that the meshing characteristic is the most sensitive to axial deviation for the model used in this paper.

Steady seepage simulation of underground oil storage caverns based on Signorini type variational inequality formulation

Yunfeng Dai,Zhifang Zhou 한국지질과학협의회 2015 Geosciences Journal Vol.19 No.2

To analyze the seepage characteristics of water-sealed underground oil storage caverns, a calculation software was programmed based on the Signorini type variational inequality formulation. The storage region and boundary condition of oil-groundwater contact surface were generalized, and a two-dimensional numerical simulation model of finite-element method was built. The seepage characteristics and the water inflow of oil storage caverns were analyzed, while the conditions of different oil levels in caverns with water curtain system were taken into account. The effect of a water curtain system was assessed, and the design parameters of water curtain system such as width, water pressure, borehole space, and elevation were evaluated. The seepage simulation model was applied to estimate the seepage field and water inflow of the Huangdao underground oil storage caverns during the future operation period.

THE EFFECT OF CONNECTIVITY FOR FRACTURED ROCKS ON FLUID FLOW THROUGH FRACTURES

YONG HUANG,ZHIFANG ZHOU 한국수자원학회 2005 한국수자원학회 학술대회 Vol.2005 No.1

One-pot Synthesis of Hierarchical Mesoporous ZSM-5 from the Assembly of Nanocrystals Using Urea as Additive

Yuanyuan Ma,Zhifang Li,Nan Zhao,Fuzhong Han,Qiubin Kan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.03

A hierarchical mesoporous ZSM-5 catalyst with aggregated nanocrystals structure was one-pot hydrothermally synthesized by using urea as the additive. The crystalline phase, morphology and hierarchical architectures were characterized by the XRD, SEM, TEM and N2 adsorption/desorption analyses. The nano-aggregates showed MFI crystalline phase and were composed of connected nanoparticles. The samples had the high surface area and the pore volume from intercrystalline among the nanoparticles due to spontaneously stacking of nanocrystals. The pyridine-adsorbed FTIR and the catalytic performances in the alkylation of phenol and tert-butyl alcohol were applied to evaluate the accessibility of acid sites and the catalytic activities for the hierarchical mesoporous ZSM-5 samples. The samples possessed high accessibility of acid sites which resulted from their large amount of mesopores, and its catalytic activity was improved dramatically. The phenol conversion could reach up to 95.6%, and the corresponding selectivity of 4-TBP and 2,4-DTBP was 44% and 51.5%, respectively.

Scale Effect of the Model Extent on Seepage Analysis of Circular Tunnels under Drained Conditions

Jian Wu,Zhifang Zhou 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.12

Numerical simulations have been widely used to predict groundwater inflow into tunnels during excavations. An appropriate geometric size of a numerical model is crucial for reducing the simulation time and ensuring the accuracy of numerical results. However, to the best of our knowledge, no information concerning the scale effect of the model extent on the seepage characteristics of tunnels under drained conditions has been published. This study evaluates how the model extent affects the tunnel inflow, drawdown, and water pressure via the Signorini type variational inequality formulation. A series of two-dimensional finite element models are conducted with various combinations of tunnel parameters, including tunnel radius, initial groundwater level, lining thickness, and relative permeability. Subsequently, a comprehensive function to yield the optimum model extent within an allowable error is proposed. Interestingly, the optimum model extent for both tunnel inflow and water pressure decreases with an increase in the relative permeability, whereas that of the drawdown exhibits the opposite pattern. A model extent of no less than 200 times the tunnel radius is recommended to acquire accurate model results and is verified with existing analytical methods. This study therefore not only highlights the drainage effect of the tunnel but also provides universal suggestions for engineering practice.