An experimental study on fracture coalescence characteristics of brittle sandstone specimens combined various flaws

Yang, Sheng-Qi Techno-Press 2015 Geomechanics & engineering Vol.8 No.4

This research aims to analyze the fracture coalescence characteristics of brittle sandstone specimen ($80{\times}160{\times}30mm$ in size) containing various flaws (a single fissure, double squares and combined flaws). Using a rock mechanics servo-controlled testing system, the strength and deformation behaviours of sandstone specimen containing various flaws are experimentally investigated. The results show that the crack initiation stress, uniaxial compressive strength and peak axial strain of specimen containing a single fissure are all higher than those containing double squares, while which are higher than those containing combined flaws. For sandstone specimen containing combined flaws, the uniaxial compressive strength of sandstone increase as fissure angle (${\alpha}$) increases from $30^{\circ}$ to $90^{\circ}$, which indicates that the specimens with steeper fissure angles can support higher axial capacity for ${\alpha}$ greater than $30^{\circ}$. In the entire deformation process of flawed sandstone specimen, crack evolution process is discussed detailed using photographic monitoring technique. For the specimen containing a single fissure, tensile wing cracks are first initiated at the upper and under tips of fissure, and anti-tensile cracks and far-field cracks are also observed in the deformation process; moreover anti-tensile cracks usually accompanies with tensile wing cracks. For the specimen containing double squares, tensile cracks are usually initiated from the top and bottom edge of two squares along the direction of axial stress, and in the process of final unstable failure, more vertical splitting failures are observed in the ligament region. When a single fissure and double squares are formed together into combined flaws, the crack coalescence between the fissure tips and double squares plays a significant role for ultimate failure of the specimen containing combined flaws.

Design and Expression of Recombinant Antihypertensive Peptide Multimer Gene in Escherichia coli BL21

Sheng Qi Rao,Yu Jie Su,Jun Hua Li,Zhen Zhen Xu,Yan Jun Yang 한국미생물 · 생명공학회 2009 Journal of microbiology and biotechnology Vol.19 No.12

Analysis on Double Rain Belts of a Rainstorm in Liaoning

YANG Qing,YAN Qi,CHEN Li-qiang,GAO Song-ying,LI Shuang,CUI Sheng-quan,LU Bing-hong 한국기상학회 2015 한국기상학회 학술대회 논문집 Vol.2015 No.10

Heteromerization of μ-opioid receptor and cholecystokinin B receptor through the third transmembrane domain of the μ-opioid receptor contributes to the anti-opioid effects of cholecystokinin octapeptide

Yin Yang,Qian Li,Qi-Hua He,Ji-Sheng Han,Li Su,You Wan 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Activation of the cholecystokinin type B receptor (CCKBR) by cholecystokinin octapeptide (CCK-8) inhibits opioid analgesia. Chronic opiate treatment leads to an increase in the CCK-8 concentration and thus enhances the antagonism of CCK-8 against opioid analgesia; the underlying molecular mechanisms remain of great interest. In the present study, we validated the colocalization of the μ-opioid receptor (MOR) and CCKBR in pain signal transmissionrelated spinal cord dorsal horn and dorsal root ganglion neurons of rats. Co-immunoprecipitation (Co-IP) and fluorescence lifetime-imaging-microscopy-based fluorescence resonance energy transfer (FLIM-FRET) assays showed that MOR heteromerized with CCKBR directly in transfected HEK293 cells. Combined with MOR mutant construction, the third transmembrane domain of MOR (TM3MOR) was demonstrated to participate in heteromerization with CCKBR. Receptor ligand binding, ERK phosphorylation and cAMP assays showed that MOR heteromerization with CCKBR weakened the activity of MOR. A cell-penetrating interfering peptide consisting of TM3MOR and TAT (a transactivator of HIV-1) sequences from the N terminal to the C terminal disrupted the MOR–CCKBR interaction and restored the activity of MOR in transfected HEK293 cells. Furthermore, intrathecal application of the TM3MOR-TAT peptide alleviated CCK-8-injection-induced antagonism to morphine analgesia in rats. These results suggest a new molecular mechanism for CCK-8 antagonism to opioid analgesia in terms of G-protein-coupled receptor (GPCR) interaction through direct heteromerization. Our study may provide a potential strategy for pain management with opioid analgesics.

Comparative genomic analysis of Mycoplasma anatis strains

Zhou Qi,Mai Kaijie,Yang Dehong,Liu Junfa,Yan Zhuanqiang,Luo Cuifen,Tan Yangtong,Cao Sheng,Zhou Qingfeng,Chen Li,Chen Feng 한국유전학회 2021 Genes & Genomics Vol.43 No.11

Background The Gram-negative intracellular bacterium Mycoplasma anatis is a pathogen of respiratory infectious diseases in ducks and has caused signifcant economic losses in the poultry industry. Objective This study, as the frst report of the structure and function of the pan-genome of Mycoplasma anatis, may provide a valuable genetic basis for many aspects of future research on the pathogens of waterfowl. Methods We sequenced the whole genomes of 15 Mycoplasma anatis isolated from ducks in China. Draft genome sequencing was carried out and whole-genome sequencing was performed by the sequencers of the PacBio Sequel and an IonTorrent Personal Genome Machine (PGM). Then the common genic elements of protein-coding genes, tRNAs, and rRNAs of Mycoplasma anatis genomes were predicted by using the pipeline Prokka v1.13.7. To investigate homologous protein clusters across Mycoplasma anatis genomes, we adopted Roary v3.13.0 to cluster orthologous genes (OGs) based on the following criteria. Results We obtained one complete genome and 14 genome sketches. Microbial mobile genetic element analysis revealed the distribution of insertion sequences (IS30, IS3, and IS1634), prophage regions, and CRISPR arrays in the genome of Mycoplasma anatis. Comparative genomic analysis decoded the genetic components and functional classifcation of the pan-genome of Mycoplasma anatis that comprised 646 core genes, 231 dispensable genes and among them 110 was strainspecifc. Virulence-related gene profles of Mycoplasma anatis were systematically identifed, and the products of these genes included bacterial ABC transporter systems, iron transport proteins, toxins, and secretion systems. Conclusion A complete virulence-related gene profle of Mycoplasma anatis has been identifed, most of the genes are highly conserved in all strains. Sequencing results are relevant to the molecular mechanisms of drug resistance, adaptive evolution of pathogens, population structure, and vaccine development.

Factors for Endoscopic Submucosal Dissection in Early Colorectal Neoplasms: A Single Center Clinical Experience in China

Yu-Qi He,Xin Wang,Lang Yang,Jian Zhang,Qian Kang,Shan Tang,Peng Jin,Jian-Qiu Sheng,Ai-Qin Li 대한소화기내시경학회 2015 Clinical Endoscopy Vol.48 No.5

Background/Aims: Early colorectal (CR) neoplasm can be cured by endoscopic submucosal dissection (ESD), but clinical experience and factors associated with complications from ESD for CR neoplasms in China have not been reported . Methods: Seventy-eight cases of early CR neoplasm treated with endoscopic resection performed between December 2012 and December 2013 at Beijing Military General Hospital were included. Factors associated with ESD complications and procedure times were evaluated. Results: The en bloc resection rate was 88.5% (69/78), tumor size was 32.1±10.7 mm, and procedure time was 71.8±49.5 minutes. The major complication was perforation, which occurred in 8.97% of the ESD procedures. Multivariate logistic regression analysis indicated that only tumor size (p=0.022) was associated with ESD perforation. Tumor size (p<0.001) and the non-lifting sign (p=0.017) were independent factors for procedure time, and procedure time (p=0.016) was a key factor for en bloc resection. After a median 10 months (range, 4 to 16) of follow-up, no patients had local recurrence. Conclusions: This study indicated that ESD is an applicable method for large early CR neoplasm in the colon and rectum. Tumor size and the non-lifting sign might be considerable factors for increased complication rate and procedural time of ESD.

Isolation of Probiotic Piliated Lactobacillus rhamnosus Strains from Human Fecal Microbiota Using SpaA Antiserum-Based Colony Immunoblotting

( Zhen-quan Yang ),( Yu Xue ),( Sheng-qi Rao ),( Mi Zhang ),( Lu Gao ),( Yong-qi Yin ),( Da-wei Chen ),( Xiao-hui Zhou ),( Xin-an Jiao ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.11

Piliated Lactobacillus rhamnosus (pLR) strains possess higher adherent capacity than non-piliated strains. The objective of this study was to isolate and characterize probiotic pLR strains in human fecal samples. To this end, mouse polyclonal antiserum (anti-SpaA) against the recombinant pilus protein (SpaA) of L. rhamnosus strain GG (LGG) was prepared and tested for its reactivity and specificity. With the anti-SpaA, a method combining the de Man, Rogosa, and Sharpe (MRS) agar plating separation and colony immunoblotting (CIB) was developed to isolate pLR from 124 human fecal samples. The genetic and phenotypic characteristics of the resultant pLR isolates were compared by randomly amplified polymorphic DNA (RAPD) fingerprinting, and examination of adhesion to Caco-2 cells, hydrophobicity, autoaggregation, and in vitro gastrointestinal tolerance. Anti-SpaA specifically reacted with three pLR strains of 25 test strains, as assessed by western blotting, immunofluorescence flow cytometry, and immunoelectron microscopy (IEM) assays. The optimized MRS agar separation plus anti- SpaA-based CIB procedure could quantitatively detect 2.5 × 10³ CFU/ml of pLR colonies spiked in 10⁶ CFU/ml of background bacteria. Eight pLR strains were identified in 124 human fecal samples, and were confirmed by 16S RNA gene sequencing and IEM identification. RAPD fingerprinting of the pLR strains revealed seven different patterns, of which only two isolates from infants showed the same RAPD profiles with LGG. Strain PLR06 was obtained with high adhesion and autoaggregation activities, hydrophobicity, and gastrointestinal tolerance. Anti-SpaA-based CIB is a rapid and inexpensive method for the preliminary screening of novel adherent L. rhamnosus strains for commercial purposes.

miR-1246 inhibits NFATc1 phosphorylation and regulates Th17 cell activation in the pathogenesis of severe alopecia areata

Si-si Qi,Ying Miao,You-yu Sheng,Rui-ming Hu,Jun Zhao,Qin-ping Yang 대한피부과학회 2023 Annals of Dermatology Vol.35 No.1

Background: We found microRNA (miR)-1246 to be significantly differentially expressedbetween severe active alopecia areata (AA) patients and healthy individuals. Objective: To explore the role and mechanism of miR-1246 in severe AA. Methods: Expression of miR-1246, dual-specific tyrosine phosphorylation-regulated kinase1A (DYRK1A), and nuclear factor of activated T cells 1c (NFATc1) in peripheral CD4+ Tcells and in scalp tissues of patients were detected using RT-qPCR, Western blot, and immunohistochemistryassays. Peripheral CD4+ T cells from the AA patients were transfectedwith lentiviral vectors overexpressing miR-1246. RT-qPCR and Western blot analysis wereused to measure mRNA or protein expression of retinoic-acid-receptor-related orphan nuclearreceptor gamma (ROR-γt), interleukin (IL)-17, DYRK1A, NFATc1, and phosphorylatedNFATc1. Flow cytometry was used to assay the CD4+IL-17+ cells proportion. ELISA wasused to measure cytokine levels. Results: miR-1246 levels decreased and DYRK1A and NFATc1 mRNA levels significantlyincreased in the peripheral CD4+ T cells and scalp tissues of severe active AA samples. NFATc1 protein expression was also significantly increased in the peripheral CD4+ T cellsbut not in the scalp tissues. NFATc1 positive cells were mainly distributed among infiltratinginflammatory cells around hair follicles. In peripheral CD4+ T cells of severe active AA,overexpression of miR-1246 resulted in significant downregulation of DYRK1A, NFATc1,ROR-γt, and IL-17 mRNA and phosphorylated NFATc1 protein, as well as a decrease in theCD4+IL-17+ cells proportion and the IL-17F level. Conclusion: miR-1246 can inhibit NFAT signaling and Th17 cell activation, which may bebeneficial in the severe AA treatment.

Measurement and correlation of phase equilibria in aqueous two-phase systems containing ionic liquid ([EOMiM]Br) and potassium citrate/ammonium citrate/potassium tartrate at different temperatures

Dongdong Wang,Yang Lu,Zhuo Sun,Wei Liang,Dongshu Sun,Changli Qi,ChengZhuo Sheng,Xiaopeng Yu 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.2

An aqueous two-phase system (ATPS) containing an ionic liquid (1-(2-methoxyethyl)-3-methylimidazolium bromide) and three organic salts (K3C6H5O7, (NH4)3C6H5O7, and K2C4H4O6) at different temperatures was designed. Binodal data were correlated using two empirical equations, and tie-line data were fit with the utilization of Bancroft and Othmer-Tobias equations. In the systems investigated, three conclusions were drawn from the study of the phase-forming ability of salt through effective excluded volume, Gibbs free energy of ions, and the phase diagram. First, if the same cations of salt were present, the ability of salt to form phases increased with increasing valence of the anion. Second, the larger the effective excluded volume, the stronger the aforementioned ability of salt in forming phases. Third, salt had more ability to form phases if cations (or anions) contained in the salt possessed higher negative Gibbs free energy when the cation (anion) of the salt was the same. The effect of temperature on ATPSs was also investigated. It was found that it was easier to form ATPSs at lower temperature, and the tie-line slope showed growing absolute values as the temperature was decreased.

Analysis of the failure mechanism and support technology for the Dongtan deep coal roadway

Chen, Miao,Yang, Sheng-Qi,Zhang, Yuan-Chao,Zang, Chuan-Wei Techno-Press 2016 Geomechanics & engineering Vol.11 No.3

The stability of deep coal roadways with large sections and thick top coal is a typical challenge in many coal mines in China. The innovative Universal Discrete Element Code (UDEC) trigon block is adopted to create a numerical model based on a case study at the Dongtan coal mine in China to better understand the failure mechanism and stability control mechanism of this kind of roadway. The failure process of an unsupported roadway is simulated, and the results suggest that the deformation of the roof is more serious than that of the sides and floor, especially in the center of the roof. The radial stress that is released is more intense than the tangential stress, while a large zone of relaxation appears around the roadway. The failure process begins from partial failure at roadway corners, and then propagates deeper into the roof and sides, finally resulting in large deformation in the roadway. A combined support system is proposed to support roadways based on an analysis of the simulation results. The numerical simulation and field monitoring suggest that the availability of this support method is feasible both in theory and practice, which can provide helpful references for research on the failure mechanisms and scientific support designing of engineering in deep coal mines.