CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Yingjie Fei,Chunying Zhu,Taotao Fu,Xiqun Gao,Youguang Ma
The deformation of moving slug bubbles and its influence on the bubble breakup dynamics in microchannel were studied. Three bubble morphologies were found in the experiment: slug, dumbbell and grenade shapes. The viscosity effect of continuous phase aggravates the velocity difference between the fluid near the wall and the bubble, resulting in that the continuous phase near the bubble head flows towards and squeezes the bubble tail, which causes the deformation of bubbles. Moreover, the experimental results show that the deformation of bubbles could significantly prolong the bubble breakup period at the downstream Y-junction. There exists the critical capillary number Ca Cr for the asymmetric breakup of grenade bubbles, Ca Cr increases with the rise of flow rate and viscosity of the continuous phase.
研究领域:
流体力学
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微流控技术
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产品关联
DOI
高影响因子
MethodsX
·
2021
·
IF 0
Yanyan Liu,Chaoqun Yao,Lixia Yang,Mei Yang,Guangwen Chen
Continuous slug flow in microreactors are featured by alternative presence of regulate segments of immiscible phases in microchannel or capillaries with lateral dimensions below 1 mm. Due to the high interfacial area and short diffusive distance therein, such microreactors have been widely applied in chemical engineering processes that are sensitive to mass transfer. Therefore, mass transfer rates in microreactors have long been broadly investigated via either typical offline or online methods. Compared to these conventional methods, the colorimetric technique based on the oxidation of resazurin with oxygen enables direct determination of physical mass transfer rates. However, this technique was currently applied only to the gas-liquid system in microreactors, and mostly in rectangular channels due to the simplicity in image processing. Based on this, the current paper showed a demo where the colorimetric technique using resazurin was adapted to a liquid-liquid system for the mass transfer study of flowing droplets within a slug flow capillary. Experimental tips and tricks were summarized, and a sliced color-concentration calibration strategy was proposed to balance analyzing efficiency and accuracy.
研究领域:
化学工程
·
分析化学
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DOI
CHEMICAL ENGINEERING RESEARCH & DESIGN
·
2019
·
IF 3.073
Tingting Guan,Qin Yan,Lizhi Wan,Songhong Zhang,Linhong Xu,Jianli Wang,Junxian Yun
For preparing cryogel beads by the micro-flow-focusing and cryo-polymerization method, liquid–liquid flow patterns and slug characteristics for the system of Dex-MA and ethyl acetate and the system of Dex-MA-HEMA and ethyl acetate in a cross-shaped square microchannel were studied. The aqueous solutions of Dex-MA-HEMA and Dex-MA were used as the dispersed phase and ethyl acetate as the continuous phase. The formation mechanism of the slug flow was illustrated by analyzing the interaction of the interfacial tension between the dispersed and continuous phases, inertial forces and viscous forces of the dispersed phase and the continuous phase. The flow pattern maps for the two systems were proposed and five regimes were identified, i.e., the slug flow, bubbly flow, jetting flow, unstable flow and stratified flow. The slug lengths and the droplet diameters were also measured experimentally and correlated. The results showed that the formation of the slug flow was related to the interaction of the forces of the continuous phase and dispersed phase. The inertial and viscous force of the continuous phase promoted while the viscous force of the dispersed phase resisted the formation of the slug flow. The interfacial tension and the inertial force of the aqueous phase were shifting their effects which either promoted or resisted the formation of the slug flow. The flow pattern maps have a good agreement with those proposed in the literatures. The velocity of the continuous phase was more influential on the length of the slug segment. The obtained correlation of slug length and the droplet diameter could be helpful to the preparation of the cryogel beads.
研究领域:
生物工程
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化学工程
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产品关联
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2019
·
IF 3.031
Wenbin Xie,Libo Zhang,Jianyu Yang,Lihua Zhang,Shaohua Ju,Yaoyao Luo
Separation of Zn 2+ from sulphate solution containing Ni 2+ and Co 2+ using di-(2-ethylhexyl)phosphoric acid (D2EHPA) has been carried out in capillary microreactors. Well-defined slug flows are formed at total flow rates of 0.1–4 mL/min, and the slugs size and specific interfacial area are determined. The effects of saponification degree of D2EHPA, extractant concentration, and residence time on extraction and separation of these three metal ions are investigated. Meanwhile, conventional batch experiments at 94 s and equilibrium experiments at 8 h are also done in parallel at different extractant concentrations. Compared with conventional batch experiments, better extraction and separation performance, e.g. 2.7–38.9 times higher of β Zn/Ni and 3.9–34.9 times higher of β Zn/Co , is obtained in the slug flow microreactor. In addition, the overall volumetric mass transfer coefficient k L a and overall mass transfer coefficient k L are measured. Compared with other microreactors and the batch mixer-settler, the used slug flow microreactor shows higher k L a values of Zn.
研究领域:
化学工程
·
材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Tingting Guan,Yawei Gao,Manman Pan,Yuwei Wu,Songhong Zhang,Linhong Xu,Lingyu Zhu,Junxian Yun
Cryogel beads are novel adsorbents with potential applications in biotechnology, environmental and tissue engineering. However, the controllable preparation of cryogel beads with expected small and uniform diameters is a challenging work. The micro-flow-focusing method combining with the cryo-polymerization has been suggested as a new approach for the fabrication of cryogel beads. In order to form the uniform droplet, the slug flow is generated in the microchannel, so the slug flow hydrodynamics are crucial and fundamental for this process. In the present work, the dextran-methacrylate (Dex-MA-PEGDA) solution and ethyl acetate containing surfactant of Span 80 were used as the aqueous phase and the water-immiscible, respectively. The fabrication of dextran-based cryogel beads and the slug flow hydrodynamics in a rectangular microchannel were investigated experimentally. The flow regime map was proposed and the typical regime boundaries were measured and correlated, and the formation mechanisms of slugs were also discussed. The regime boundaries were correlated by Weber number and Capillary number, i.e., We o = 58.16 Ca w 0.92 for the boundary between the annular and the slug flow, and We o = 4.12 Ca w 0.09 for the slug and the bubbly flow, respectively. Several crucial parameters of the droplets generated by the slug flow, i.e., the aqueous slug length, the aqueous slug velocity and the aqueous droplet size, were measured and correlated. The Dex-MA-PEGDA cryogel beads were prepared successfully under different conditions and their diameters were correlated to the sizes of the droplets. Eventually, the uniform size distributions and supermacroporous microstructures of dextran-based cryogel beads were demonstrated.
研究领域:
化学工程
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生物技术
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材料科学
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产品关联
DOI
高影响因子
DNA AND CELL BIOLOGY
·
2020
·Vol. 39
·期 3
·355-367
·
IF 3.314
Jiuwei Zhang,Yaodong Chen,Jing Lin,Ruimei Jia,Tingting An,Tianxiu Dong,Yu Zhang,Xiuhua Yang
Hepatocellular carcinoma (HCC), the sixth most common malignancy worldwide, is characterized by a dismal prognosis due to high recurrence and metastasis rates. Thus, the need for the development of novel chemotherapeutic drugs is urgent. Cyclovirobuxine D (CVB-D), a steroidal alkaloid extracted from Buxus microphylla that has been extensively used to relieve the symptoms of cardiovascular diseases, has shown promising antineoplastic effects in recent studies. However, the therapeutic effects and underlying mechanisms of CVB-D on HCC remain largely unelucidated. This study experimentally indicated that CVB-D can repress HCC cell proliferation by arresting the cell cycle in G2 phase and can facilitate apoptosis. In addition, the migratory and invasive capabilities of HCC cells were noticeably attenuated by a nonlethal dose of CVB-D, and this attenuation was correlated with the inhibition of epithelial–mesenchymal transition (EMT). Moreover, in vivo, CVB-D displayed excellent anticancer effects in HCC tumor-bearing nude mice. Regarding the molecular mechanisms of CVB-D activity, decreased Slug expression was determined to be associated with the aforementioned anti-HCC functions of this extract, which might be regulated by epidermal growth factor receptor (EGFR) through the focal adhesion kinase (FAK)-associated PI3K/AKT and MEK/ERK1/2 signaling pathways. Collectively, our results revealed the suppressive effects of CVB-D on progressive behaviors of HCC, including proliferation, migration, invasion, and EMT, in addition to its outstanding proapoptotic effects, which were correlated with the inhibition of the EGFR-FAK-AKT/ERK1/2-Slug signaling pathway. These discoveries provide an experimental and theoretical foundation for the use of CVB-D as a promising candidate for HCC therapy.
研究领域:
肿瘤学
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药理学
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分子生物学
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细胞生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH
·
2019
·Vol. 38
·期 1
·1-15
·
IF 5.646
Li Zizhuo,Chen Yaodong,An Tingting,Liu Pengfei,Zhu Jiyuan,Yang Haichao,Zhang Wei,Dong Tianxiu,Jiang Jian,Zhang Yu,Jiang Maitao,Yang Xiuhua
Background Nuciferine (NF), extracted from the leaves of N. nucifera Gaertn, has been shown to exhibit anti-tumor and anti-viral pharmacological properties. It can also penetrate the blood brain barrier (BBB). However, the mechanism by which NF inhibits glioblastoma (GBM) progression is not well understood. We aimed to determine the anti-tumor effect of NF on GBM cell lines and clarify the potential molecular mechanism involved.Methods U87MG and U251 cell lines were used in vitro to assess the anti-tumor efficacy of NF. Cytotoxicity, viability, and proliferation were evaluated by MTT and colony formation assay. After Annexin V-FITC and PI staining, flow cytometry was performed to evaluate apoptosis and cell cycle changes in NF-treated GBM cells. Wound healing and Transwell assays were used to assess migration and invasion of GBM cells. Western blot analysis, immunofluorescence staining, immunohistochemistry, and bioinformatics were used to gain insights into the molecular mechanisms. Preclinical therapeutic efficacy was mainly estimated by ultrasound and MRI in xenograft nude mouse models.Results NF inhibited the proliferation, mobility, stemness, angiogenesis, and epithelial-to-mesenchymal transition (EMT) of GBM cells. Additionally, NF induced apoptosis and G2 cell cycle arrest. Slug expression was also decreased by NF via the AKT and STAT3 signaling pathways. Interestingly, we discovered that NF affected GBM cells partly by targeting SOX2, which may be upstream of the AKT and STAT3 pathways. Finally, NF led to significant tumor control in GBM xenograft models.Conclusion sNF inhibited the progression of GBM via the SOX2-AKT/STAT3-Slug signaling pathway. SOX2-targeting with NF may offer a novel therapeutic approach for GBM treatment.
研究领域:
肿瘤学
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药理学
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神经科学
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分子生物学
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细胞生物学
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产品关联
DOI
PubMed
高影响因子
ACS Agricultural Science & Technology
·
2024
·
IF 2.3
Jian Zhang,Yi Zhang,Shan-shan Chen,Su-xia Zhang,Yun-hai Guo,Zhen-peng Kai
Slugs pose a significant threat to agriculture, causing substantial crop damage and economic losses. Traditional molluscicides harm nontarget organisms and endanger ecosystems. Environmentally friendly molluscicides that ensure safety for humans and animals and promote sustainable agriculture are urgently needed. This study is the first to explore the fumigant toxicity, contact toxicity, and repellent effects of four monoterpenoids (geraniol, citral, geranyl nitrile, and citronellal) against Philomycus bilineatus. Compared to metaldehyde, monoterpenoids exhibited stronger contact toxicity, leading to rapid slug elimination (within 4 h), while metaldehyde caused death in slugs over a longer period of 48 h. Among the monoterpenoids, citral has weaker contact toxicity compared with the other three compounds, and geranyl nitrile (GN) and citronellal have stronger fumigant toxicity than the other two compounds. In terms of repellence and antifeeding effects, citral has the weakest toxicity. GN and citronellal stand out with excellent molluscidal activity (LC50 values of 0.10 and 0.14 g/L, respectively). The computational results based on the density functional theory (DFT) indicate that appropriate energy gaps, electrophilicity indices, and molecular softness correlate with the high molluscidal activity of monoterpenoids. From the computational results of this study, GN and citronellal, which have a moderate energy gap (approximately 0.200 eV), show the best effectiveness in controlling the slugs. In addition, unlike metaldehydes, which have a long half-life and limited biodegradability, these monoterpenoids have low toxicity and are easily degradable in the environment, making them more environmentally friendly. These findings underscore the potential of monoterpenoid compounds as eco-friendly alternatives for managing slugs in agriculture and gardens, thereby reducing reliance on traditional chemical pesticides.
研究领域:
农业科学
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环境科学
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植物保护
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2022
·
IF 3.898
Yanyan Liu,Chaoqun Yao,Guangwen Chen
Gas–liquid–liquid three-phase slug flow was generated in both hydrophilic and hydrophobic microreactors with double T-junctions. The bubble-droplet relative movement and the local mass transfer within the continuous slug and the dispersed droplet were investigated. It was found that bubbles moved faster than droplets under low capillary number ( Ca ), while droplets moved faster upon the increase of Ca due to the increased inertia. For the first time, we observed that the increased viscosity of droplets fastened the droplet movement. The mass transfer in the continuous slug was dominated by convection, leading to nearly constant global mass transfer coefficient ( k L a ); while that in the dispersed droplet was dominated by diffusion, resulting in k L decreasing along the channel. Such features are analogical to the corresponding gas–liquid or liquid–liquid two-phase slug flow, but the formation of bubble-droplet clusters caused by relative movement lowered the absolute mass transfer coefficient. These results provide insights for the precise manipulation of gas–liquid–liquid slug flow in microreactors towards process optimization.
研究领域:
化学工程
·
流体力学
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Minglei Li,Yaheng Zhang,Jie Zhang,Min Peng,Liuming Yan,Zhiyong Tang,Qing Wu
Gas–liquid–solid (G–L–S) three-phase slug flow provides an efficient pathway to utilize solid catalysts in continuous flow and was adopted in the mesoporous graphite carbon nitride (mpg-C3N4)-catalyzed photoinduced electron/energy transfer reversible addition–fragmentation chain transfer (PET-RAFT) polymerization of methyl methacrylate (MMA) in this work. Kinetic studies and chain extension experiments illustrated the realization of reversible deactivation radical polymerization (RDRP) and the “easy to scale up” advantage of a continuous-flow reactor as compared to its batch counterpart. The light intensity played an important role on the PET-RAFT polymerization. An increasing amount of photocatalyst favored the monomer conversion within a limited range due to higher light blockage, and the monomer conversion reached a stable level at a lower catalyst concentration when higher light power was applied. When compared with fully continuous flow, the G–L–S slug flow was beneficial to the PET-RAFT polymerization due to the intensified swirling strength and narrower velocity field. Decreasing the gas-to-slurry ratio also led to narrower velocity distribution, which favored the polymerization as well. Moreover, the polymerization rates remained stable in multiple recycles, demonstrating that the present G–L–S slug flow was a reliable and easy processing approach for utilizing the solid catalyst.
研究领域:
化学工程
·
高分子化学
·
催化科学
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产品关联
DOI
高影响因子
AICHE JOURNAL
·
2019
·Vol. 66
·期 2
·e16805
·
IF 3.463
Yanyan Liu,Jun Yue,Chao Xu,Shuainan Zhao,Chaoqun Yao,Guangwen Chen
Gas–liquid–liquid three-phase slug flow was generated in a glass microreactor with rectangular microchannel, where aqueous slugs were distinguished by relative positions to air bubbles and organic droplets. Oxygen from bubbles reacted with resazurin in slugs, leading to prominent color changes, which was used to quantify mass transfer performance. The development of slug length indicated a film flow through the corner between bubbles and the channel wall, where the aqueous phase was saturated with oxygen transferred from bubble body. This film flow results in the highest equivalent oxygen concentration within the slug led by a bubble and followed by a droplet. The three-phase slug flow subregime with alternate bubble and droplet was found to benefit the overall mass transfer performance most. These results provide insights into a precise manipulation of gas–liquid–liquid slug flow in microreactors and the relevant mass transfer behavior thereof.
研究领域:
化学工程
·
微流控技术
·
多相流
·
传质过程
·
反应工程
✓ 已验证
DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2020
·
IF 2.952
Jianfeng Mei,Xiaoyun Zhao,Yu Yi,Yanlu Zhang,Xudong Wang,Guoqing Ying
Natural astaxanthin is widely used as a food and cosmetics additive because of its multiple biological activities. However, astaxanthin produced by Haematococcus pluvialis is generally esterified, and its activity is far less than that of free astaxanthin. Hydrolysis of astaxanthin esters to free astaxanthin by enzymes can overcome the drawbacks of chemical saponification methods. In this paper, a slug-flow microchannel reactor was constructed and tested in enzymatic hydrolysis of astaxanthin esters. The reactor consists of a “T” slug-flow generator, a stainless-steel microchannel, two constant-flow pumps, and a temperature controller. The reactor has the advantages of simple configuration and easy scale-up, and is suitable for two-phase biochemical reactions. Using the microchannel reactor, astaxanthin esters in H. pluvialis oil were efficiently hydrolyzed to free astaxanthin by lipase from Aspergillus niger . After hydrolysis, the content of free astaxanthin in H. pluvialis oil was 18.8 mg/L, 7.83-times higher than that before hydrolysis (2.13 mg/L). The hydrolysis rate reached 75.4 %. These results indicate that the microchannel reactor can be useful for the production of free astaxanthin from its esters.
研究领域:
生物化学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）