Kinetic study on carbonation of crude Li_2CO_3 with CO_2-water solutions in a slurry bubble column reactor

Wen-Tao Yi,Chun-Yan Yan,Pei-Hua Ma 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.3

Investigations were conducted to purify crude Li_2CO_3 via direct carbonation with CO_2-water solutions at atmospheric pressure. The experiments were carried out in a slurry bubble column reactor with 0.05 m inner diameter and 1.0 m height. Parameters that may affect the dissolution of Li_2CO-3 in the CO_2-water solutions such as CO-2-bubble perforation diameter, CO_2 partial pressure, CO_2 gas flow rate, Li-2CO-3 particle size, solid concentration in the slurry,reaction temperature, slurry height in the column and so on were investigated. It was found that the increases of CO_2partial pressure, and CO_2 flow rate were favorable to the dissolution of Li_2CO_3, which had the opposite effects with Li_2CO_3 particle size, solid concentration, slurry height in the column and temperature. On the other hand, in order to get insight into the mechanism of the refining process, reaction kinetics was studied. The results showed that the kinetics of the carbonation process can be properly represented by 1−3(1−X)^(2/3)+2(1−X)=kt+b, and the rate-determining step of this process under the conditions studied was product layer diffusion. Finally, the apparent activation energy of the carbonation reaction was obtained by calculation. This study will provide theoretical basis for the reactor design and the optimization of the process operation.

Systematic Review and Meta-Analysis of Antibiotic-Impregnated Shunt Catheters on Anti-Infective Effect of Hydrocephalus Shunt

Zhou, Wen-xiu,Hou, Wen-bo,Zhou, Chao,Yin, Yu-xia,Lu, Shou-tao,Liu, Guang,Fang, Yi,Li, Jian-wen,Wang, Yan,Liu, Ai-hua,Zhang, Hai-jun The Korean Neurosurgical Society 2021 Journal of Korean neurosurgical society Vol.64 No.2

Objective : Shunt infection is a common complication while treating hydrocephalus. The antibiotic-impregnated shunt catheter (AISC) was designed to reduce shunt infection rate. A meta-analysis was conducted to study the effectiveness of AISCs in reduction of shunt infection in terms of age, follow-up time and high-risk patient population. Methods : This study reviewed literature from three databases including PubMed, EMBASE, and Cochrane Library (from 2000 to March 2019). Clinical studies from controlled trials for shunt operation were included in this analysis. A subgroup analysis was performed based on the patient's age, follow-up time and high-risk population. The fixed effect in RevMan 5.3 software (Cochrane Collaboration) was used for this meta-analysis. Results : This study included 19 controlled clinical trials including 10105 operations. The analysis demonstrated that AISC could reduce the infection rate in shunt surgery compared to standard shunt catheter (non-AISC) from 8.13% to 4.09% (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.40-0.58; p=0.01; I2=46%). Subgroup analysis of different age groups showed that AISC had significant antimicrobial effects in all three groups (adult, infant, and adolescent). Follow-up time analysis showed that AISC was effective in preventing early shunt infections (within 6 months after implant). AISC is more effective in high-risk population (OR, 0.24;95% CI, 0.14-0.40; p=0.60; I2=0%) than in general patient population. Conclusion : The results of meta-analysis indicated that AISC is an effective method for reducing shunt infection. We recommend that AISC should be considered for use in infants and high-risk groups. For adult patients, the choice for AISC could be determined based on the treatment cost.

Antimycobacterial Activity of Fusaric Acid from a Mangrove Endophyte and its Metal Complexes

Jia-Hui Pan,Yi Chen,Yu-Hong Huang,Yi-Wen Tao,Jun Wang,Yan Li,Yi Peng,Tao Dong,Xiao-Min Lai,Yong-Cheng Lin 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.7

Due to the increasing prevalence of multidrug-resistant Mycobacterium tuberculosis, there is an urgent need for new antituberculosis drugs that have novel mechanisms of action. As part of our ongoing search for antimycobacterial metabolites from mangrove endophytes, chemical analysis of the active extract of a strain of Fusarium sp. was performed, which led to the isolation of fusaric acid as the predominant constituent. A variety of metal complexes of fusaric acid were prepared. Antimycobacterial assays showed that Cadmium (II) and Copper (II) complexes exhibited potent inhibitory activity against the M. bovis BCG strain [minimum inhibitory concentration (MIC) = 4 μg/mL] and the M. tuberculosis H37Rv strain (MIC = 10 μg/mL), respectively. This is the first report of the antimycobacterial activity of the mangrove Fusarium metabolite and its coordinating metal complexes.

Mest Attenuates CCl4-Induced Liver Fibrosis in Rats by Inhibiting the Wnt/β-Catenin Signaling Pathway

( Wen Ting Li ),( Chuan Long Zhu ),( Yi Li ),( Quan Wu ),( Ren Tao Gao ) 대한소화기학회 2014 Gut and Liver Vol.8 No.3

Background/Aims: The Wnt/β-catenin signaling pathway has been reported to play an important role in liver fibrosis. This study was designed to investigate whether mesoderm-specific transcript homologue (Mest), a strong negative regulator of Wnt/β-catenin signaling, could inhibit liver fibrosis. Methods: pcDNA-Mest was transfected into hepatic stellate cells (HSCs) and rats. Rats were randomly divided into four groups: normal group (normal saline), treatment group (pcDNA- Mest+CCl4), control group (pcDNA-neo+CCl4), and model group (normal saline+CCl4). Changes in liver pathology were evaluated by hematoxylin and eosin and Masson’s trichrome staining. The levels of alanine transaminase, aspartate transaminase, lactic dehygrogenase, hyaluronic acid, and laminin in the serum and hydroxyproline in the liver were detected by biochemical examination and radioimmunoassay, respectively. The expression and distribution of β-catenin, α-smooth muscle actin (α-SMA), Smad3, and tissue inhibitor of metalloproteinase type I were determined, and the viability of the HSCs was tested. Results: Our data demonstrate that Mest alleviated CCl4-induced collagen deposition in liver tissue and improved the condition of the liver in rats. Mest also significantly reduced the expression and distribution of β-catenin, α-SMA and Smad3 both in vivo and in vitro, in addition to the viability of HSCs in vitro. Conclusions: We found that Mest attenuates liver fibrosis by repressing β-catenin expression, which provides a new therapeutic approach for treating liver fibrosis.

Exploring the Key Genes and Pathways of Osteoarthritis in Knee Cartilage in a Rat Model Using Gene Expression Profiling

Yi-Ming Ren,Xin Zhao,Tao Yang,Yuan-Hui Duan,Yun-Bo Sun,Wen-Jun Zhao,Meng-Qiang Tian 연세대학교의과대학 2018 Yonsei medical journal Vol.59 No.6

Purpose: To compare differentially expressed genes (DEGs) mediating osteoarthritis (OA) in knee cartilage and in normal kneecartilage in a rat model of OA and to identify their impact on molecular pathways associated with OA. Materials and Methods: A gene expression profile was downloaded from the Gene Expression Omnibus database. Analysis ofDEGs was carried out using GEO2R. Enrichment analyses were performed on the Gene Ontology (GO) and Kyoto Encyclopedia ofGenes and Genomes pathway using the Search Tool for the Retrieval of Interacting Genes database (http://www.string-db.org/). Subsequently, the regulatory interaction network of OA-associated genes was visualized using Cytoscape software (version 3.4.0;www.cytoscape.org). Results: In the gene expression profile GSE103416, a total of 99 DEGs were identified. Among them, 76 DEGs (76.77%) were overexpressed,and the remaining 23 DEGs (23.23%) were underexpressed. GO and pathway enrichment analyses of target geneswere performed. Using gene-gene interaction network analysis, relevant core genes, including MET, UBB, GNAI3, and GNA13,were shown to hold a potential relationship with the development of OA in cartilage. Using quantitative real-time PCR, the Gna13/cGMP-PKG signaling pathway was identified as a potential research target for therapy and for further understanding the developmentof OA. Conclusion: The results of the present study provide a comprehensive understanding of the roles of DEGs in knee cartilage in relationto the development of OA.

Preparation of BiPO4-Polyaniline Hybrid and its Enhanced Photocatalytic Performance

Wen Jie Yu,Yang Cheng,Tao Zou,Yi Liu,Kui Wu,Na Peng 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.1

Recently, BiPO4 has been proved to be an efficient photocatalyst which exhibits more attractive activity than that of TiO2-P25 under UV irradiation. However, photocatalytic oxidation-reduction ability of BiPO4 under visible light still needs to be improved. Conjugated polymer just like polyaniline was demonstrated to be a new and efficient visible co-photocatalyst in the field of pollutant governance. As far as we know, the attempt to enhance the photochemical ability of BiPO4 by employing polyaniline as a co-photocatalyst is still very limited. Hence, in order to testify the potential enhanced performance of such heterostructure, BiPO4-polyaniline heterostructure was prepared via hydrothermal method and hybridization in this paper. The experimental results indicated that several typical pollutants such as organic dyes and heavy metal ions can be effectively removed by BiPO4-polyaniline under visible light. The enhanced removal mechanism was attributed to the high separation efficiency of photo-induced electron–hole pairs and more efficient absorption of visible light after the loading of polyaniline on the surface of BiPO4 as an out-layer compared with single BiPO4.

Growth of SiGe Film By Using A Single-wafer Rapid Thermal Processing UHV/CVD System

Wen Tao Huang,Chang Chun Chen,Xi You Li,Xiao Yi Xiong,Zhi Hong Liu,Wei Zhang,Jun Xu,Pei Hsin Tsien 대한금속학회 2004 METALS AND MATERIALS International Vol.10 No.5

Convenient hydrogel adhesion with crystalline zones

Wen-Tao Chen,Liangpeng Zeng,Ping Li,Yi Liu,Jing-Liang Huang,Hui Guo,Ping Rao,Wei-Hua Li 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.117 No.-

Adhering soft hydrogels to hard substrates is challenging. Existing adhesion approaches mainly rely oninterfacial chemical bonds or physical interactions, which typically require complex fabrication processesor specific surface properties. Herein, we report a convenient approach to achieving effective hydrogeladhesion onto various hard substrates with in-situ formed crystalline zones by heating. Semicrystallizablepoly(vinyl alcohol) hydrogels were directly cast on various subtracts by a dryingswellingprocess, which demonstrates strong adhesion with adhesion energy as high as 890 J/m2. Theadhesion performance demonstrates an obvious positive correlation with the crystalline property. Therefore, the factors determining the crystalline degree, including the polymer type and preparationtemperature, demonstrate remarkable influences on the adhesion performance. Moreover, this adhesionperformance manifests high durability in harsh environments. Benefitting from the strong and durableadhesion performance, the crystalline gels can serve as a tie coating layer to joint various hydrogels,which demonstrate satisfactory antifouling ability. Therefore, this strategy may endow the materials withgreat potential for various practical applications in the future.

Investigation on separation principle of vanadium and chromium among Fe2VO4-CaO-FeCr2O4 system: Simplify and simulate calcification roasting process of vanadium-chromium slag

Jing Wen,Tao Jiang,Hongyan Sun,Tangxia Yu,Ming Li,Yi Peng 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-

The competitive reaction of vanadium and chromium with calcium additives, along with the formationmechanism of calcium vanadate and calcium chromate are the central issue to the efficient separationand extraction of vanadium and chromium from vanadium-chromium slag (V-Cr slag) by calcificationroasting. In this study, Fe2VO4 and FeCr2O4 were synthesized to simulate the vanadium chromium spinelin V-Cr slag; then, the reaction mechanism of Fe2VO4-CaO-FeCr2O4 powder system was studied by XRD,SEM and leaching experiments. Results showed that calcium vanadate and calcium chromate are generatedafter roasting Fe2VO4-CaO system and FeCr2O4-CaO system individually. In Fe2VO4-CaO-FeCr2O4 system,as n(CaO)/n(V2O3) is 2, vanadium exists in the form of Ca2V2O7 while almost all Cr2O3 from thedecomposition of FeCr2O4 reacts with Fe2O3 to continuously form solid solution with more FeCr2O4 adding. After leaching, the addition of FeCr2O4 has no obvious effect on the leaching ratio of vanadium, andthe leaching ratio of chromium decrease with FeCr2O4 adding. Consequently, 94.03% of vanadium and0.15% of chromium are leached with n(CaO)/n(V2O3)/n(Cr2O3) of 2/1/1.03 at 900 C. When n(CaO)/n(V2O3) is 4, Fe2VO4 is oxidized and calcified gradually to form Ca2V2O7 and Ca3V2O8 with increasing roastingtemperature. A small amount of CaCrO4 is generated owing to the calcification of chromium, and mostchromium still exists in the form of solid solution. The reaction result of Cr2O3 and Fe2O3 is the superpositionof solid solution reactions with different degrees. Increasing the roasting temperature can significantlyreduce the chromium leaching ratio. All above would provide a theoretical support for thecalcification roasting process from V-Cr slag.

Interventional Therapy for Renal Artery Pseudoaneurysms

Ji, Wen-Bin,Wang, Wei-Zheng,Sun, Song,Mi, Yu-Cheng,Xu, Qiong,Chen, Yi-Er,Yang, Song,Tao, Dan,Xu, Wei,Xu, Chao Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

The aim of this study was to explore the angiographic diagnosis and embolization therapy for renal artery pseudoaneurysms due to acute urinary tract hemorrhage after conservative medical management failed. Seven out of ten cases had fever symptoms after the kidney surgery. The pseudoaneurysms were treated with gelatin sponge and (or) spring coil and the majority demonstrated rapid blockage of hemorrhage. Angiography diagnosis and trans catheter embolization are rapid, safe and effective methods for diagnosis and treatment of renal artery pseudoaneurysms.