This paper proposes a type of double-layer charge liner fabricated using chemical vapor deposition(CVD)that has tungsten as its inner liner.The feasibility of this design was evaluated through penetration tests.Double...This paper proposes a type of double-layer charge liner fabricated using chemical vapor deposition(CVD)that has tungsten as its inner liner.The feasibility of this design was evaluated through penetration tests.Double-layer charge liners were fabricated by using CVD to deposit tungsten layers on the inner surfaces of pure T2 copper liners.The microstructures of the tungsten layers were analyzed using a scanning electron microscope(SEM).The feasibility analysis was carried out by pulsed X-rays,slug-retrieval test and static penetration tests.The shaped charge jet forming and penetration law of inner tungsten-coated double-layer liner were studied by numerical simulation method.The results showed that the double-layer liners could form well-shaped jets.The errors between the X-ray test results and the numerical results were within 11.07%.A slug-retrieval test was found that the retrieved slug was similar to a numerically simulated slug.Compared with the traditional pure copper shaped charge jet,the penetration depth of the double-layer shaped charge liner increased by 11.4% and>10.8% respectively.In summary,the test results are good,and the numerical simulation is in good agreement with the test,which verified the feasibility of using the CVD method to fabricate double-layer charge liners with a high-density and high-strength refractory metal as the inner liner.展开更多
The condensed tumor extracellular matrix(ECM)consisting of cross-linked hyaluronic acid(HA)is one of the key factors that result in the aberrant tumor microenvironment and severely impair drug delivery and tumor penet...The condensed tumor extracellular matrix(ECM)consisting of cross-linked hyaluronic acid(HA)is one of the key factors that result in the aberrant tumor microenvironment and severely impair drug delivery and tumor penetration.Herein,we report a simple design of a hyaluronidase(HAase)-modified layered double hydroxide(LDH)nanoplatform loaded with anticancer drug doxorubicin(DOX)for enhanced tumor penetration and augmented chemotherapy.In our approach,LDH nanodisks were synthesized via a co-precipitation method,modified with HAase by electrostatic attraction,and finally physically loaded with DOX.The formulated DOX/LDH-HAase complexes show a high DOX loading percentage of 34.2%with good colloidal stability,retain 86.1%of the enzyme activity,and release DOX in a pH-responsive manner having a faster release rate under slightly acidic tumor microenvironment than that under a physiological condition.With the catalytic activity of HAase to digest the HA nearby the cancer cells,the developed DOX/LDH-HAase complexes enable more significant uptake by cancer cells and penetration in 3-dimensional tumor spheroids than enzyme-free DOX/LDH complexes,thus displaying much better antitumor efficacy in vitro than the latter.The more significant tumor penetration and inhibition of the DOX/LDH-HAase complexes than that of the DOX/LDH complexes was further demonstrated by in vivo tumor imaging and therapeutic activity assessments.Our study suggests a unique nanomedicine platform combined with both anticancer drug and enzyme for improved tumor penetration and chemotherapy,which is promising for effective chemotherapy of different types of stroma-rich tumors.展开更多
This study presented a novel circular cofferdam for offshore bridges consisting of ring segments and investigated its structural behaviors using ANSYS Mechanical. Because the bottom segment of the cofferdam which has ...This study presented a novel circular cofferdam for offshore bridges consisting of ring segments and investigated its structural behaviors using ANSYS Mechanical. Because the bottom segment of the cofferdam which has a double sleeve cross-section was installed by suction, contact behaviors of the cofferdam wall and the lid plate during installation are important for design and the behaviors were also analyzed. Prior to numerical investigation of the bottom segment and complete cofferdam after dewatering, a suction modeling for structural analysis was proposed and evaluate by seepage analysis. Hydrodynamic loads applied to the cofferdam were also evaluated using panel method based on the potential flow theory. Through numerical analyses, structural behaviors of the cofferdam during installation were then investigated. First, contact behaviors between the lid plate and the wall were analyzed using different contact conditions imposed on the interface. Sharp stress increases were shown while the stress jumps were limited to contact area. Next, structural behaviors were investigated by considering seepage pressure. Using an axisymmetric seepage model, the total water pressure considering seepage was estimated and applied to structural analysis. The analysis results showed that strong effects of seepage on the stress change in cofferdam occurred and the seepage effects are necessary to be considered in design of the cofferdam induced by suction.展开更多
Layered double hydroxides （LDHs） are effective molecular carriers in cytological research, gene therapy, and transgenic applications. Herein, we investigated the internalization behavior of the LDH-DNA biocon- jugat...Layered double hydroxides （LDHs） are effective molecular carriers in cytological research, gene therapy, and transgenic applications. Herein, we investigated the internalization behavior of the LDH-DNA biocon- jugates via a microscopic approach and analyzed the internalization pathway by dissipative particle dynamics （DPD） simulations. We experimentally found that LDH can efficiently carry DNA into the nucleus of cell in BY-2 suspension cells. Furthermore, atomic force microscopy and X-ray diffraction anal- ysis demonstrated that the LDH-DNA bioconjugates mainly exist as a DNA-LDH-DNA sandwich complex, while the LDH-DNA-LDH sandwich complex and DNA-LDH complex cannot be excluded. The DPD simu- lations further indicated that only the DNA-LDH-DNA sandwich structure could penetrate the plasma membrane （PM）, while PM is impermeable to the LDH-DNA-LDH sandwich complex and the DNA-LDH complex. This work provides novel perspective for understanding the membrane penetration mechanism of LDH nano-sheets and new insights into the design of novel molecular delivery systems.展开更多
基金funded by the China Postdoctoral Science Foundation(Grant No.2022M721614)the opening project of State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology(Grant No.KFJJ23-07M)。
文摘This paper proposes a type of double-layer charge liner fabricated using chemical vapor deposition(CVD)that has tungsten as its inner liner.The feasibility of this design was evaluated through penetration tests.Double-layer charge liners were fabricated by using CVD to deposit tungsten layers on the inner surfaces of pure T2 copper liners.The microstructures of the tungsten layers were analyzed using a scanning electron microscope(SEM).The feasibility analysis was carried out by pulsed X-rays,slug-retrieval test and static penetration tests.The shaped charge jet forming and penetration law of inner tungsten-coated double-layer liner were studied by numerical simulation method.The results showed that the double-layer liners could form well-shaped jets.The errors between the X-ray test results and the numerical results were within 11.07%.A slug-retrieval test was found that the retrieved slug was similar to a numerically simulated slug.Compared with the traditional pure copper shaped charge jet,the penetration depth of the double-layer shaped charge liner increased by 11.4% and>10.8% respectively.In summary,the test results are good,and the numerical simulation is in good agreement with the test,which verified the feasibility of using the CVD method to fabricate double-layer charge liners with a high-density and high-strength refractory metal as the inner liner.
基金This work was supported by the National Natural Science Foundation of China(81761148028,21773026,82001830)the National Key R&D Program(2017YFE0196200)+1 种基金the Science and Technology Commission of Shanghai Municipality(19XD1400100,19410740-200,20520710300)and the Shanghai Education Commission through the Shanghai Leading Talents Program.
文摘The condensed tumor extracellular matrix(ECM)consisting of cross-linked hyaluronic acid(HA)is one of the key factors that result in the aberrant tumor microenvironment and severely impair drug delivery and tumor penetration.Herein,we report a simple design of a hyaluronidase(HAase)-modified layered double hydroxide(LDH)nanoplatform loaded with anticancer drug doxorubicin(DOX)for enhanced tumor penetration and augmented chemotherapy.In our approach,LDH nanodisks were synthesized via a co-precipitation method,modified with HAase by electrostatic attraction,and finally physically loaded with DOX.The formulated DOX/LDH-HAase complexes show a high DOX loading percentage of 34.2%with good colloidal stability,retain 86.1%of the enzyme activity,and release DOX in a pH-responsive manner having a faster release rate under slightly acidic tumor microenvironment than that under a physiological condition.With the catalytic activity of HAase to digest the HA nearby the cancer cells,the developed DOX/LDH-HAase complexes enable more significant uptake by cancer cells and penetration in 3-dimensional tumor spheroids than enzyme-free DOX/LDH complexes,thus displaying much better antitumor efficacy in vitro than the latter.The more significant tumor penetration and inhibition of the DOX/LDH-HAase complexes than that of the DOX/LDH complexes was further demonstrated by in vivo tumor imaging and therapeutic activity assessments.Our study suggests a unique nanomedicine platform combined with both anticancer drug and enzyme for improved tumor penetration and chemotherapy,which is promising for effective chemotherapy of different types of stroma-rich tumors.
文摘This study presented a novel circular cofferdam for offshore bridges consisting of ring segments and investigated its structural behaviors using ANSYS Mechanical. Because the bottom segment of the cofferdam which has a double sleeve cross-section was installed by suction, contact behaviors of the cofferdam wall and the lid plate during installation are important for design and the behaviors were also analyzed. Prior to numerical investigation of the bottom segment and complete cofferdam after dewatering, a suction modeling for structural analysis was proposed and evaluate by seepage analysis. Hydrodynamic loads applied to the cofferdam were also evaluated using panel method based on the potential flow theory. Through numerical analyses, structural behaviors of the cofferdam during installation were then investigated. First, contact behaviors between the lid plate and the wall were analyzed using different contact conditions imposed on the interface. Sharp stress increases were shown while the stress jumps were limited to contact area. Next, structural behaviors were investigated by considering seepage pressure. Using an axisymmetric seepage model, the total water pressure considering seepage was estimated and applied to structural analysis. The analysis results showed that strong effects of seepage on the stress change in cofferdam occurred and the seepage effects are necessary to be considered in design of the cofferdam induced by suction.
基金supported by the Fundamental Research Funds for the Central Universities (2016JX01, BLX2015-01)the National Natural Science Foundation of China (31671489, 31601149 and 31271433)+2 种基金the Beijing Nova Programme (Z131109000413013)the Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fundthe Chemical Grid Program and Excellent Talent of Beijing University of Chemical Technology
文摘Layered double hydroxides （LDHs） are effective molecular carriers in cytological research, gene therapy, and transgenic applications. Herein, we investigated the internalization behavior of the LDH-DNA biocon- jugates via a microscopic approach and analyzed the internalization pathway by dissipative particle dynamics （DPD） simulations. We experimentally found that LDH can efficiently carry DNA into the nucleus of cell in BY-2 suspension cells. Furthermore, atomic force microscopy and X-ray diffraction anal- ysis demonstrated that the LDH-DNA bioconjugates mainly exist as a DNA-LDH-DNA sandwich complex, while the LDH-DNA-LDH sandwich complex and DNA-LDH complex cannot be excluded. The DPD simu- lations further indicated that only the DNA-LDH-DNA sandwich structure could penetrate the plasma membrane （PM）, while PM is impermeable to the LDH-DNA-LDH sandwich complex and the DNA-LDH complex. This work provides novel perspective for understanding the membrane penetration mechanism of LDH nano-sheets and new insights into the design of novel molecular delivery systems.
