Experimental investigation on the contribution of gas molecular diffusion to gas mass flux in micro-nano pores

Jing Sun,Dehua Liu,Xiang Zhu,Wenjun Huang,Liang Cheng 한국자원공학회 2020 Geosystem engineering Vol.23 No.1

The mass transfer from the matrix to the fracture face is driven by both concentration and pressure differences. In this work, high-temperature high-pressure (HPHT) systems for diffusion experiments with only concentration differences were used to determine the diffusion coefficient, and flow experiments with only pressure differences were also conducted; and the magnitude of gas molecular diffusion and its contribution to production were analyzed in this study. The results show as follows: (1) Gas flow from the matrix to the fracture system is driven by the combined effect of gas molecular diffusion and seepage. The pore structure characteristics of the reservoir and the contribution of the diffusion to the yield can vary greatly. (2) In tight reservoirs with an average permeability of 0.3067 mD, the contribution of gas molecular diffusion to the total gas mass flux is only 0.08%, while in shale reservoirs, the average permeability is 0.0015 mD; the contribution of diffusion to the total gas mass flux could be as large as 1%. (3) The contribution of molecular diffusion to gas production is closely related to the pore sizes of the porous medium. The smaller the pore sizes are, the greater the contribution of molecular diffusion to gas production.

Prognostic Value of Tissue Vascular Endothelial Growth Factor Expression in Bladder Cancer: a Meta-analysis

Huang, Yu-Jing,Qi, Wei-Xiang,He, Ai-Na,Sun, Yuan-Jue,Shen, Zan,Yao, Yang Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.2

Objective: The prognostic role of vascular endothelial growth factor (VEGF) in bladder cancer remains controversial. This meta-analysis aimed to explore any association between overexpression and survival outcomes. Methods: We systematically searched for studies investigating the relationships between VEGF expression and outcome of bladder cancer patients. Study quality was assessed using the Newcastle-Ottawa Scale. After careful review, survival data were extracted from eligible studies. A meta-analysis was performed to generate combined hazard ratios (HRs) for overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS). Results: A total of 1,285 patients from 11 studies were included in the analysis. Our results showed that tissue VEGF overexpression in patients with bladder cancer was associated with poor prognosis in terms of OS (HR, 1.843; 95% CI, 1.231-2.759; P = 0.003), DFS (HR, 1.498; 95% CI, 1.255-1.787; P = 0.000) and DSS (HR, 1.562; 95% CI, 0.996-1.00; P = 0.052), though the difference for DSS was not statistically significant. In addition, there was no evidence of publication bias as suggested by Begg's and Egger's tests except for DFS (Begg's test, P = 0.221; Egger's test, P = 0.018). Conclusion: The present meta-analysis indicated elevated VEGF expression to be associated with a poor prognosis in patients with bladder cancer.

Investigation on the Thermal Oxidative Aging Mechanism and Lifetime Prediction of Butyl Rubber

Kewei Xiang,Guangsu Huang,Jing Zheng,Xiaoan Wang,Jingyun Huang 한국고분자학회 2013 Macromolecular Research Vol.21 No.1

Accelerated thermal aging experiments were conducted on butyl rubber materials in order to investigate aging behavior using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), positron annihilation lifetime spectroscopy (PALS), and differential scanning calometry (DSC). The XPS results suggested that the thermal oxidation process took place heterogeneously along the samples thicknesses. The aging mechanism was identified to be crosslinking by means of the combined use of PALS and DSC results. Lifetime and intensity of ortho-positronium (o-ps) diminished, and the glass transition temperature (Tg) increased during aging. The dispersion condition of silica particles, observed by SEM images, showed that the filler agglomerated after aging. Time temperature superposition was carried out using compression set measurements in the temperature range of 100 to 60 oC. The Arrhenius plot clearly exhibited a curvature around 75 oC, and the activation energy dropped from 126.7to 58.8 kJ/mol across this region. Relative importance of different processes, over the entire temperature range, was discussed; lifetime at room temperature was predicted.

Relaxation Behavior and Time-Temperature Superposition (TTS) Profiles of Thermally Aged Styrene-Butadiene Rubber (SBR)

Kewei Xiang,Guangsu Huang,Siduo Wu,Jing Zheng,Jingyun Huang,Guangxian Li 한국고분자학회 2014 Macromolecular Research Vol.22 No.8

In this work, styrene-butadiene rubber (SBR) was thermally aged at 130 ℃with ageing period up to 4days. The relaxation behavior was studied by dynamic mechanical analysis (DMA) in temperature scanning modeat multifrequencies and the crosslinking network was characterized by swelling method. Glass transition temperature(Tg) and activation energies (Ea) during transition evaluated by Starkweather method were found to increaseafter ageing. Time-temperature superposition (TTS) procedure was performed to obtain master curve and shift factors(αT). The derived αTs were fitted by William-Landel-Ferry (WLF) and Vogel-Fulcher-Tamman (VFT) equations. WLF fitting parameters confirmed decreased free volume fraction ( f ) and thermal expansion coefficient (αf)near Tg versus ageing time. Temperature dependent relaxation properties were examined by VFT fitting parameterD. It was found that the aged SBR displayed more brittle behavior, becoming more and more deviated from Arrheniusfashion. This phenomenon was illustrated by the enhanced intermolecular coupling and severe crosslinkingduring ageing.

Fabrication of magnetically recyclable ZrO2-TiO2/CoFe2O4 hollow core/shell photocatalysts: Improving photocatalytic efficiency under sunlight irradiation

Hong-xia Jing,Jing Huang,Na Li,Long-xiang Li,Jingyue Zhang 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.4

TiO2 is an important material for photocatalytic oxidation to degrade organic pollutants, but its utilization under visible light is low, recovery is difficult, and stability is poor. We prepared ZrO2-TiO2/CoFe2O4 (Zr-Ti/Co) photocatalyst with hollow core-shell structure by sol-gel method and layer-by-layer self-assembly method with tetrabutyl titanate and Zirconium n-butoxide as main raw materials. The samples were characterized and analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), solid ultraviolet visible diffuse reflection (UV-Vis DRS), fluorescence (FL), ultraviolet visible absorption (UV), vibrating sample magnetometer (VSM). It is concluded that the TiO2 maintains a good anatase phase structure in the Zr-Ti-Co photocatalyst. Under UV light and sunlight, the degradation rate of the photocatalyst reached 96.1% and 99.7% for 60 min, respectively, for Rhodamine B (10mg/L) reaction system. And after repeated use for five times, it still showed better regeneration and reuse.

Structure and Properties of Polyimide (BTDA-TDI/MDI co-polyimide) Fibers Obtained by Wet-Spinning

Hong Bing Xiang,Zhong Huang,Li Qi Liu,Lei Chen,Jing Zhu,Zu Ming Hu,Jun Rong Yu 한국고분자학회 2011 Macromolecular Research Vol.19 No.7

BTDA-TDI/MDI (P84, synthesized by the condensation of 2,4-diisocyanato-1-methylbenzene and 1,1' -methylenebis(4-isocyanatobenzene) with 5,5'-carbonylbis(l,3-isobenzofurandione)) co-polyimide fibers were prepared by wet-spinning. The basic spinning conditions were found from the studies of dope viscosity, ternary phase diagrams, coagulation value, and precipitation value. The effect of the coagulation bath composition on the morphology of as-spun fibers was investigated and a theoretical approach was used to understand the coagulation phenomena. Scanning electron microscopy (SEM) showed that the cross-sectional shape of the fiber deviated more from an ellipse shape with the increasement of N-methyl-2-pyrrdidinone (NMP) content. The surface and cross section morphology of the as-spun fibers was also analyzed by the rate of diffusion and phase separation. The as-spun fibers were treated in heating tubes without drawing at different temperatures. The gravimetric analysis spectra showed that the BTDA-TDI/MDI co-polyimide fibers, which had been heat treated at 350 and 400 ℃, possessed better thermal properties than the as-spun fibers, a large weight loss was observed only above 550 ℃. Heat treatment of the fibers resulted in relatively high tensile strength and modulus. The fibers spun in Bath C (70/30, NMP/water, wt/wt)and Bath D (80/20, NMP/water, wt/wt) showed better thermal properties and higher tensile strength.

China Consensus Document on Allergy Diagnostics

Chen Hao,Li Jing,Cheng Lei,Gao Zhongshan,Lin Xiaoping,Zhu Rongfei,Yang Lin,Tao Ailin,Hong Haiyu,Tang Wei,Guo Yinshi,Huang Huaiqiu,Sun Jinlyu,Lai He,Lei Cheng,Liu Guanghui,Xiang Li,Chen Zhuanggui,Ma Ha 대한천식알레르기학회 2021 Allergy, Asthma & Immunology Research Vol.13 No.2

The prevalence of allergic diseases has increased dramatically in recent years in China, affecting the quality of life in 40% of the population. The identification of allergens is the key to the diagnosis of allergic diseases. Presently, several methods of allergy diagnostics are available in China, but they have not been standardized. Additionally, cross-sensitization and co-sensitization make allergy diagnostics even more complicated. Based on 4 aspects of allergic disease (mechanism, diagnosis procedures, allergen detection in vivo and in vitro as well as the distribution map of the most important airborne allergens in China) and by referring to the consensus of the European Society of Allergy and Clinical Immunology, the World Allergy Organization, and the important literature on allergy diagnostics in China in recent years, we drafted this consensus of allergy diagnostics with Chinese characteristics. It aims to standardize the diagnostic methods of allergens and provides a reference for health care givers. The current document was prepared by a panel of experts from the main stream of professional allergy associations in China.

Toxoplasma gondii induces autophagy and apoptosis in human umbilical cord mesenchymal stem cells via downregulation of Mcl−1

Chu, Jia-Qi,Jing, Kai-Peng,Gao, Xiang,Li, Peng,Huang, Rui,Niu, Yan-Ru,Yan, Shou-Quan,Kong, Jun-Chao,Yu, Cai-Yuan,Shi, Ge,Fan, Yi-Ming,Lee, Young-Ha,Zhou, Yu,Quan, Juan-Hua Landes Bioscience 2017 Cell Cycle Vol.16 No.5

<P>Autophagy and apoptosis are critical for controlling Toxoplasma gondii (T. gondii) infection. T. gondii infection during pregnancy can damage the fetus and cause birth defects; however, the molecular mechanisms of this process are poorly understood. This study aims to determine the activities of autophagy and apoptosis as well as their regulatory mechanisms during T. gondii infection by using human umbilical cord mesenchymal stem cells (hUC-MSCs) as a model of congenital diseases. LC3B, a hallmark protein of autophagy was incrementally upregulated with the infection duration, whereas p62 was downregulated in T. gondii-infected hUC-MSCs. Concurrent to this result, the invasion of T. gondii into hUC-MSCs increased in a time-dependent manner. The expression levels of Bcl-2 family proteins including Bcl-2, Bcl-xL, Bim, Bax, Bid and Bak were not altered; however, Mcl-1 levels in hUC-MSCs were dramatically decreased upon T. gondii infection. In addition, at 24h post-infection, cleaved PARP and cleaved caspase-3 protein levels were elevated in hUC-MSCs. Importantly, Mcl-1 overexpression reduced the levels of autophagy- and apoptosis-related proteins in T. gondii-infected hUC-MSCs. Mcl-1 proteins were primarily expressed in the fraction containing mitochondria and strongly interacted with Beclin-1 under normal conditions; however, these interactions were remarkably attenuated by T. gondii infection. These results suggest that mitochondrial Mcl-1 is an essential signaling mediator regulating the activation of autophagy and apoptosis during T. gondii infection.</P>

Blood-compatible Polyaniline Coated Electrospun Polyurethane Fiber Scaffolds for Enhanced Adhesion and Proliferation of Human Umbilical Vein Endothelial Cells

Yumei Li,Rui Zhao,Xiang Li,Chuying Wang,Huiwei Bao,Shudan Wang,Jing Fang,Jinqiu Huang,Ce Wang 한국섬유공학회 2019 Fibers and polymers Vol.20 No.2

The endothelialization and anti-thrombotic abilities of tissue engineered vascular scaffolds are considered to be effective properties for improving the performance small-caliber vascular scaffolds. For this purpose, we designed and developed electrically conductive fibrous scaffolds based on polyaniline coated polyurethane (PANI-PU) electrospun fibersfor vascular tissue engineering applications. The porosity of PANI-PU fibers was 75.27±2.04 %. The obtained PANI-PU fibers were characterized by SEM observations, XPS analysis, water contact angle (WCA) measurement and mechanical property. The PANI functionalization aimed to improve the performance of anticoagulation and endothelialization. The WCA of PAIN-PU decreased to 35 o from 135 o of PU fibers. Blood compatibility and cytocompatibility were compared before and after PANI coating. The adhered platelet cells on PANI-PU was 6.87×105/cm2 and plasma recalcification time was 123 s. Platelet adhesion and plasma recalcification time test showed that the PANI-PU scaffolds had a certain anticoagulant effect. The hemolysis rate of PANI-PU fibers was 0.14 %, which showed that the PANI-PU scaffolds could be used as blood contact materials. The observation of endothelial cell proliferation and morphology in human umbilical vein endothelial cells showed that PANI-PU fibers were more beneficial to cell adhesion, proliferation and extension than that of PU fibers. The results demonstrates the PANI coated electrospun PU fibers have great potential in application as small-diameter vascular grafts and this work shows new insights into conductive scaffolds for vascular tissue engineering.

Isolation and characterization of LHT-type plant amino acid transporter gene from Panax ginseng Meyer

Ru Zhang,Jie Zhu,Hong-Zhe Cao,Xiao-Lei Xie,Jing-Jia Huang,Xiang-Hui Chen,Zhi-Yong Luo 고려인삼학회 2013 Journal of Ginseng Research Vol.37 No.3

A lysine histidine transporter (LHT) cDNA was isolated and characterized from the roots of Panax ginseng, designated PgLHT. The cDNA is 1,865 bp with an open reading frame that codes for a protein with 449 amino acids and a calculated molecular mass of 50.6 kDa with a predicted isoelectric point of 8.87. Hydropathy analysis shows that PgLHT is an integral membrane protein with 9 putative membrane-spanning domains. Multiple sequence alignments show that PgLHT shares a high homology with other plant LHTs. The expression profile of the gene was investigated by real-time quantitative polymerase chain reaction during various chemical treatments. PgLHT was up-regulated in the presence of abscisic acid, salicylic acid, methyl jasmonate, NaCl, and amino acids. To further explore the function of PgLHT gene, full-length cDNA of PgLHT was introduced into P. ginseng by Agrobacterium rhizogenes A4. The overexpression of PgLHT in the hairy roots led to an obviously increase of biomass compared to the controls, and after addition of the amino acids, the overexpressed-PgLHT hairy roots grew more rapidly than untreated controls during early stage of the culture cycle. The results suggested that the PgLHT isolated from ginseng might have role in the environmental stresses and growth response.