J.C. Guo, P. Rong, L. Wang, W.J. Chen, S.X. Han, R.N. Yang, X.W. Lei, W. Yao, N. Wang
Abstract The substrate orientation can affect the stray grain formation in laser remelted single crystal superalloys. A systematic investigation on the effect of substrate orientation on stray grain susceptibility was performed by varying laser scanning directions on three most conventional crystallographic planes (001), (011), and (111). We found that the scanning direction has a drastic effect on stray grain formation in (011) and (111) planes but shows less impact in (001) plane. The comparison of different planes reveals that the stray gain susceptibility in (011) plane is the weakest whereas that in (111) plane is the strongest. This can be attributed to the lower volume fraction of the local stray grains on the (011) plane. Our results show that stray grain can be depressed most effectively if a laser repair is performed in (011) plane along [100] direction, which can provide an in-depth insight into the mechanism of how to avoid stray grain formation in the future laser repair of single crystal components.
{"title":"A Comparable Study on Stray Grain Susceptibilities on Different Crystallographic Planes in Single Crystal Superalloys","authors":"J.C. Guo, P. Rong, L. Wang, W.J. Chen, S.X. Han, R.N. Yang, X.W. Lei, W. Yao, N. Wang","doi":"10.2139/ssrn.3649207","DOIUrl":"https://doi.org/10.2139/ssrn.3649207","url":null,"abstract":"Abstract The substrate orientation can affect the stray grain formation in laser remelted single crystal superalloys. A systematic investigation on the effect of substrate orientation on stray grain susceptibility was performed by varying laser scanning directions on three most conventional crystallographic planes (001), (011), and (111). We found that the scanning direction has a drastic effect on stray grain formation in (011) and (111) planes but shows less impact in (001) plane. The comparison of different planes reveals that the stray gain susceptibility in (011) plane is the weakest whereas that in (111) plane is the strongest. This can be attributed to the lower volume fraction of the local stray grains on the (011) plane. Our results show that stray grain can be depressed most effectively if a laser repair is performed in (011) plane along [100] direction, which can provide an in-depth insight into the mechanism of how to avoid stray grain formation in the future laser repair of single crystal components.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"106 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91432575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chang Gao, Yu Zhao, Weili Li, Yulong Qiao, Wang Zhao, Lu Jing, J. Sheng, W. Fei
Piezoelectric thin film materials are high energy density materials that scale very favorably upon miniaturization and that has led to an ever-growing interest for MEMS applications. Thus extensive investigation of lead-free piezoelectric has been triggered out of environmental awareness. Here, a concrete lead-free paradigm is presented, Zn1-2x(FexLix)O thin films, which exhibits a splendid d33* value (~415 pm/V) and electrostrain (~0.68%) after thermal-electric treatment in the co-doped film with the x value of 0.06. It is considered that the local lattice distortion generated by preferential distributed Fe3+-Li+ ionic pairs is responsible for the outstanding piezoelectric properties and obvious ferroelectricity response. The defect engineering strategy presented in this work open a new development window for obtaining excellent piezoelectricity in a wide range of binary metal oxide systems and have profound implications for the potential utilization of lead-free piezoelectrics in microelectromechanical systems and surface acoustic wave devices.
{"title":"Giant Piezoelectric Properties of ZnO Film Doped with Acceptor-Donor Ionic Pair","authors":"Chang Gao, Yu Zhao, Weili Li, Yulong Qiao, Wang Zhao, Lu Jing, J. Sheng, W. Fei","doi":"10.2139/ssrn.3746789","DOIUrl":"https://doi.org/10.2139/ssrn.3746789","url":null,"abstract":"Piezoelectric thin film materials are high energy density materials that scale very favorably upon miniaturization and that has led to an ever-growing interest for MEMS applications. Thus extensive investigation of lead-free piezoelectric has been triggered out of environmental awareness. Here, a concrete lead-free paradigm is presented, Zn1-2x(FexLix)O thin films, which exhibits a splendid d33* value (~415 pm/V) and electrostrain (~0.68%) after thermal-electric treatment in the co-doped film with the x value of 0.06. It is considered that the local lattice distortion generated by preferential distributed Fe3+-Li+ ionic pairs is responsible for the outstanding piezoelectric properties and obvious ferroelectricity response. The defect engineering strategy presented in this work open a new development window for obtaining excellent piezoelectricity in a wide range of binary metal oxide systems and have profound implications for the potential utilization of lead-free piezoelectrics in microelectromechanical systems and surface acoustic wave devices.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"76 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75161398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Considering the key roles of macrophages in tissue repair and immune therapy, designing smart biomaterials able to harness macrophage phenotypes on demand during the healing process has become a promising strategy. Here, a novel "sandwich" cell culture platform with near-infrared (NIR) responsive dynamic stiffness was fabricated to polarize bone marrow-derived macrophages (BMDMs) in situ for revealing the relationship between the macrophage phenotype and substrate stiffness dynamically. Under NIR irradiation, calcium ions (Ca2+) diffused through the middle layer of the IR780-mixed phase change material (PCM) due to the photothermal effect of IR780, resulting in an increase of hydrogel stiffness in situ by the crosslinking of the upper layer of the hyaluronic acid-sodium alginate hydrogel (MA-HA&SA). The up-regulation of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) was quantified by immunostaining and enzyme-linked immune sorbent assay (ELISA), respectively, indicating the transformation of macrophages from the anti-inflammatory to pro-inflammatory phenotype under dynamic stiffness. The nuclear Yes-associated-protein (YAP) ratio positively correlated with the shift of the macrophage phenotype. The modulation of macrophage phenotypes by stiffness-rise without the stimuli of cytokines offers an effective and noninvasive strategy to manipulate immune reactions to achieve optimized healing or therapeutic outcomes.
{"title":"A 'Sandwich' Cell Culture Platform with NIR-Responsive Dynamic Stiffness to Modulate Macrophage Phenotypes","authors":"Peiqi Yuan, Yilun Luo, Yuan Luo, Lie Ma","doi":"10.2139/ssrn.3743220","DOIUrl":"https://doi.org/10.2139/ssrn.3743220","url":null,"abstract":"Considering the key roles of macrophages in tissue repair and immune therapy, designing smart biomaterials able to harness macrophage phenotypes on demand during the healing process has become a promising strategy. Here, a novel \"sandwich\" cell culture platform with near-infrared (NIR) responsive dynamic stiffness was fabricated to polarize bone marrow-derived macrophages (BMDMs) in situ for revealing the relationship between the macrophage phenotype and substrate stiffness dynamically. Under NIR irradiation, calcium ions (Ca2+) diffused through the middle layer of the IR780-mixed phase change material (PCM) due to the photothermal effect of IR780, resulting in an increase of hydrogel stiffness in situ by the crosslinking of the upper layer of the hyaluronic acid-sodium alginate hydrogel (MA-HA&SA). The up-regulation of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-α (TNF-α) was quantified by immunostaining and enzyme-linked immune sorbent assay (ELISA), respectively, indicating the transformation of macrophages from the anti-inflammatory to pro-inflammatory phenotype under dynamic stiffness. The nuclear Yes-associated-protein (YAP) ratio positively correlated with the shift of the macrophage phenotype. The modulation of macrophage phenotypes by stiffness-rise without the stimuli of cytokines offers an effective and noninvasive strategy to manipulate immune reactions to achieve optimized healing or therapeutic outcomes.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"30 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83317807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Shamsolhodaei, J. P. Oliveira, B. Panton, B. Ballesteros, N. Schell, Y.N. Zhou
Abstract Laser microwelding was used to join, for the first time, superelastic NiTi to biomedical PtIr which can be used in multicomponent biomedical devices. By process optimization, it was possible to control the formation of the B2 NiTiPt, with no intermetallic compounds being formed. The NiTiPt phase inside the fusion zone had a strong metallurgical bonding with the NiTi base material due to the smooth transition of its grain orientation towards B2 NiTi. The major finding of the present work is the preservation of the NiTi superelastic response in the welded joint as evidenced by the load/unloading cycling up to 6 % strain, significantly higher than typically required for biomedical applications.
{"title":"Superelasticity Preservation in Dissimilar Joint of NiTi Shape Memory Alloy to Biomedical PtIr","authors":"A. Shamsolhodaei, J. P. Oliveira, B. Panton, B. Ballesteros, N. Schell, Y.N. Zhou","doi":"10.2139/ssrn.3739623","DOIUrl":"https://doi.org/10.2139/ssrn.3739623","url":null,"abstract":"Abstract Laser microwelding was used to join, for the first time, superelastic NiTi to biomedical PtIr which can be used in multicomponent biomedical devices. By process optimization, it was possible to control the formation of the B2 NiTiPt, with no intermetallic compounds being formed. The NiTiPt phase inside the fusion zone had a strong metallurgical bonding with the NiTi base material due to the smooth transition of its grain orientation towards B2 NiTi. The major finding of the present work is the preservation of the NiTi superelastic response in the welded joint as evidenced by the load/unloading cycling up to 6 % strain, significantly higher than typically required for biomedical applications.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78665596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael A. Casasanta, G. Jonaid, Liam Kaylor, William Y. Luqiu, Maria J. Solares, Mariah Schroen, W. Dearnaley, Jarad J. Wilson, M. Dukes, Deborah F. Kelly
Interest in cryo-Electron Microscopy (EM) imaging has skyrocketed in recent years due to its pristine views of macromolecules and materials. As advances in instrumentation and computing algorithms spurred this progress, there is renewed focus to address specimen-related challenges. Here we contribute a microchip-based toolkit to perform complementary structural and biochemical analysis on low molecular-weight proteins. As a model system, we used the SARS-CoV-2 nucleocapsid (N) protein (48 kDa) due to its stability and important role in therapeutic development. Cryo-EM structures of the N protein monomer revealed a flexible N-terminal “top hat” motif and a helical-rich C-terminal domain. To complement our structural findings, we engineered microchip-based immunoprecipitation assays that led to the discovery of the first antibody binding site on the N protein. The data also facilitated molecular modeling of a variety of pandemic and common cold-related coronavirus proteins. Such insights may guide future pandemic-preparedness protocols through immuno-engineering strategies to mitigate viral outbreaks.
{"title":"Microchip-Based Structure Determination of Small Proteins Using Cryo-EM","authors":"Michael A. Casasanta, G. Jonaid, Liam Kaylor, William Y. Luqiu, Maria J. Solares, Mariah Schroen, W. Dearnaley, Jarad J. Wilson, M. Dukes, Deborah F. Kelly","doi":"10.2139/ssrn.3737809","DOIUrl":"https://doi.org/10.2139/ssrn.3737809","url":null,"abstract":"Interest in cryo-Electron Microscopy (EM) imaging has skyrocketed in recent years due to its pristine views of macromolecules and materials. As advances in instrumentation and computing algorithms spurred this progress, there is renewed focus to address specimen-related challenges. Here we contribute a microchip-based toolkit to perform complementary structural and biochemical analysis on low molecular-weight proteins. As a model system, we used the SARS-CoV-2 nucleocapsid (N) protein (48 kDa) due to its stability and important role in therapeutic development. Cryo-EM structures of the N protein monomer revealed a flexible N-terminal “top hat” motif and a helical-rich C-terminal domain. To complement our structural findings, we engineered microchip-based immunoprecipitation assays that led to the discovery of the first antibody binding site on the N protein. The data also facilitated molecular modeling of a variety of pandemic and common cold-related coronavirus proteins. Such insights may guide future pandemic-preparedness protocols through immuno-engineering strategies to mitigate viral outbreaks.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82352340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-31DOI: 10.15587/1729-4061.2020.211933
V. Krasnov, O. Orlov, O. Zhukovskyi, M. Korbut, I. Davydova, V. Melnyk, O. Zborovska
Radioactive contamination of the above-ground phytomass of marsh Labrador tea (Ledum palustre L.) in different periods after the Chernobyl accident was studied. Marsh Labrador tea is widely used in official and folk medicine. The studied species grows in over-moistened pine (less mixed) forests and open oligotrophic and mesotrophic marshes. It was found that in the first four years since the beginning of observations (1991), the magnitude of the specific activity of 137Cs in above-ground vegetative phytomass of marsh Labrador tea, depending on a permanent sample area (PSA), decreased by 1.2–1.4 times. After 10 years, it decreased by 1.6–1.7 times, after 16 years by 1.9–2.1 times, after 21 years by 2.7–3.1 times, and after 27 years by 3.1–6.5 times. An increase in the magnitude of transitions factors was also observed on all PSA over time. Thus, the minimal increase within 1991–2018 was recorded in PSA 11 – by 1.2 times and on PSA 13 – by 1.4 times. The maximum decrease in the magnitude of transition coefficient was observed in PSA 16 – by 2.7 times, in PSA 15 – by 3.0 times, and in PSA 18 – by 2.0 times. It was found that marsh Labrador tea belongs to the group of plants that are characterized by the high content of 137Cs in the above-ground vegetative phytomass. Within the observation period (1991–2018), this content significantly exceeds the admissible levels of radionuclide content in plant medicinal raw materials that are used for manufacturing medical preparations. In the PSA with maximum magnitudes of soil contamination density (400.5±50.73 kBk·m-2) this excess made up 158.4 times in 1991, and 33.7 times (166.9±23.56 kBk·m-2) in 2018. For 27 years of observations, there has been a decrease in the density of radioactive soil contamination by 2.1–2.7 times, which is due to radionuclide decomposition, its vertical migration in the soil, and towards the components of forest ecosystems.
{"title":"Comparing the Radioactive Contamination of Marsh Labrador Tea (Ledum Palustre L.) Over Different Periods Since Chernobyl Accident","authors":"V. Krasnov, O. Orlov, O. Zhukovskyi, M. Korbut, I. Davydova, V. Melnyk, O. Zborovska","doi":"10.15587/1729-4061.2020.211933","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.211933","url":null,"abstract":"Radioactive contamination of the above-ground phytomass of marsh Labrador tea (Ledum palustre L.) in different periods after the Chernobyl accident was studied. Marsh Labrador tea is widely used in official and folk medicine. The studied species grows in over-moistened pine (less mixed) forests and open oligotrophic and mesotrophic marshes. It was found that in the first four years since the beginning of observations (1991), the magnitude of the specific activity of 137Cs in above-ground vegetative phytomass of marsh Labrador tea, depending on a permanent sample area (PSA), decreased by 1.2–1.4 times. After 10 years, it decreased by 1.6–1.7 times, after 16 years by 1.9–2.1 times, after 21 years by 2.7–3.1 times, and after 27 years by 3.1–6.5 times. An increase in the magnitude of transitions factors was also observed on all PSA over time. Thus, the minimal increase within 1991–2018 was recorded in PSA 11 – by 1.2 times and on PSA 13 – by 1.4 times. The maximum decrease in the magnitude of transition coefficient was observed in PSA 16 – by 2.7 times, in PSA 15 – by 3.0 times, and in PSA 18 – by 2.0 times. It was found that marsh Labrador tea belongs to the group of plants that are characterized by the high content of 137Cs in the above-ground vegetative phytomass. Within the observation period (1991–2018), this content significantly exceeds the admissible levels of radionuclide content in plant medicinal raw materials that are used for manufacturing medical preparations. In the PSA with maximum magnitudes of soil contamination density (400.5±50.73 kBk·m-2) this excess made up 158.4 times in 1991, and 33.7 times (166.9±23.56 kBk·m-2) in 2018. For 27 years of observations, there has been a decrease in the density of radioactive soil contamination by 2.1–2.7 times, which is due to radionuclide decomposition, its vertical migration in the soil, and towards the components of forest ecosystems.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78446095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-30DOI: 10.15587/1729-4061.2020.214826
Vadym Volokh, E. Kim, T. Fesenko, A. Petryshchev, S. Artemev, B. Tsymbal, L. Makarenko, A. Hedzyk, V. Slabko, V. Khmelovskyi
Phase composition and microstructure of the doping alloy obtained by regenerative smelting of technogenic wastes were studied. This is necessary to determine technological characteristics that increase the degree of extraction of doping elements during the processing of technogenic raw materials and subsequent use of the alloying material. It was determined that at a Si:C atomic ratio in the charge at a level of 0.05–0.19 (O:C atomic ratio is 1.25), a solid solution of carbon and doping elements in γ-Fe, Fe 3 Si, and Fe 5 Si 3 was found in the alloy. At Si:C atomic ratio at a level of 0.05 in the alloy, a solid solution of carbon and alloying elements in γ-Fe was dominating with a weak manifestation of Fe 3 Si. When the value of Si:C atomic ratio was increased to 0.09, Fe 5 Si 3 was found together with Fe 3 Si. A gradual increase in Si:C atomic ratio to 0.09, 0.12, and 0.19 led to a higher manifestation of Fe 3 Si and Fe 5 Si 3 . The microstructure of the alloy in the entire studied range of Si:C ratio values in the charge was characterized by the presence of several phases with different contents of doping elements. The content of elements in the studied areas (at. %) was 1.65–52.10 for Ni, 2.80–53.92 for Cr, 0.19–13.48 for Mo, 0.40–12.21 for W, 13.85–33.85 for Nb, 2.40–6.63 for Ti. An increase in Si:C atomic ratio in the charge from 0.05 to 0.19 caused an increase in silicon concentration in the studied areas of the microstructure (from 0.28 at. %) to 6.31 at. %. According to an analysis of the sample areas, carbon content was characterized by figures from 2.07 at. % to 14.23 at. %). Some of the investigated particles with a high content of W, Mo, Nb corresponded to complex carbide compounds with a high probability. Based on the study results, it can be pointed out that the most favorable Si C atomic ratio in the charge is 0.12 (with an O:C atomic ratio of 1.25). The resulting product had a relatively low content of silicon and carbon but was sufficient enough to provide the required reducing and deoxidizing strength of the alloy
{"title":"Identifying the Features of Structural and Phase Transformations in Processing the Waste of Metallurgical Products Doped with Refractory Elements","authors":"Vadym Volokh, E. Kim, T. Fesenko, A. Petryshchev, S. Artemev, B. Tsymbal, L. Makarenko, A. Hedzyk, V. Slabko, V. Khmelovskyi","doi":"10.15587/1729-4061.2020.214826","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.214826","url":null,"abstract":"Phase composition and microstructure of the doping alloy obtained by regenerative smelting of technogenic wastes were studied. This is necessary to determine technological characteristics that increase the degree of extraction of doping elements during the processing of technogenic raw materials and subsequent use of the alloying material. It was determined that at a Si:C atomic ratio in the charge at a level of 0.05–0.19 (O:C atomic ratio is 1.25), a solid solution of carbon and doping elements in γ-Fe, Fe 3 Si, and Fe 5 Si 3 was found in the alloy. At Si:C atomic ratio at a level of 0.05 in the alloy, a solid solution of carbon and alloying elements in γ-Fe was dominating with a weak manifestation of Fe 3 Si. When the value of Si:C atomic ratio was increased to 0.09, Fe 5 Si 3 was found together with Fe 3 Si. A gradual increase in Si:C atomic ratio to 0.09, 0.12, and 0.19 led to a higher manifestation of Fe 3 Si and Fe 5 Si 3 . The microstructure of the alloy in the entire studied range of Si:C ratio values in the charge was characterized by the presence of several phases with different contents of doping elements. The content of elements in the studied areas (at. %) was 1.65–52.10 for Ni, 2.80–53.92 for Cr, 0.19–13.48 for Mo, 0.40–12.21 for W, 13.85–33.85 for Nb, 2.40–6.63 for Ti. An increase in Si:C atomic ratio in the charge from 0.05 to 0.19 caused an increase in silicon concentration in the studied areas of the microstructure (from 0.28 at. %) to 6.31 at. %. According to an analysis of the sample areas, carbon content was characterized by figures from 2.07 at. % to 14.23 at. %). Some of the investigated particles with a high content of W, Mo, Nb corresponded to complex carbide compounds with a high probability. Based on the study results, it can be pointed out that the most favorable Si C atomic ratio in the charge is 0.12 (with an O:C atomic ratio of 1.25). The resulting product had a relatively low content of silicon and carbon but was sufficient enough to provide the required reducing and deoxidizing strength of the alloy","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"460 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76962960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A detailed experimental study of the processes involved in the transition between the β” and β’ metastable phases in an Al-Mg-Si is presented. Measurements were performed by means of differential scanning calorimetry (DSC) and Vickers microhardness (Hv). A combination of isothermal and non-isothermal heat treatments, aimed to study the transition to β’ with different degrees of transformed fraction of β”, were applied. Due to the proximity and overlapping of the events, the techniques of DSC and Hv for non-isothermal treatments were combined in order to obtain a better description. The obtained results were also related to the evolution observed for isothermal treatments, making the results independent of the heating rate. The results showed the presence of a dissolution in the transition β”→ β’, that this dissolution corresponds to the (at least partial) dissolution of the β” phase and that it is always present in the transition.
{"title":"Study of the β\"→ β' Transition in an Al-Mg-Si Alloy","authors":"V. Noseda Grau, A. Cuniberti","doi":"10.2139/ssrn.3721066","DOIUrl":"https://doi.org/10.2139/ssrn.3721066","url":null,"abstract":"A detailed experimental study of the processes involved in the transition between the β” and β’ metastable phases in an Al-Mg-Si is presented. Measurements were performed by means of differential scanning calorimetry (DSC) and Vickers microhardness (Hv). A combination of isothermal and non-isothermal heat treatments, aimed to study the transition to β’ with different degrees of transformed fraction of β”, were applied. Due to the proximity and overlapping of the events, the techniques of DSC and Hv for non-isothermal treatments were combined in order to obtain a better description. The obtained results were also related to the evolution observed for isothermal treatments, making the results independent of the heating rate. The results showed the presence of a dissolution in the transition β”→ β’, that this dissolution corresponds to the (at least partial) dissolution of the β” phase and that it is always present in the transition.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74259441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yue Ding, Yuxuan Ma, Chang Du, Chenwei Wang, Tingting Chen, Yang Wang, Jin Wang, Yong Yao, Changming Dong
The multidrug resistance (MDR) induced by the overexpression of P-glycoprotein (P-gp) transporters mainly leads to the chemotherapy (CT) failure. Herein, a novel NIR/pH dual-sensitive charge-reversal polypeptide nanocomposite (PDA-PLC) was developed for co-delivering nitric oxide (NO) donor and doxorubicin (DOX). Under intelligent near-infrared (NIR) irradiation, the released high-concentration NO could inhibit the P-gp expression to reverse MDR, and assist photothermal therapy (PTT) to eradicate cancer cells without skin scarring. Meanwhile, the distinctive charge-reversal capacity of PDA-PLC significantly facilitates the cellular uptake at tumor acid microenvironment (pH 6.8) and enhances its stability at physiological environment (pH 7.4). This DOX-loading polypeptide nanocomposites PDA-PLC/DOX provide an effective strategy for the PTT-NO-CT triple-combination therapy to overcome MDR.
p -糖蛋白(P-gp)转运体过度表达引起的多药耐药(MDR)是化疗(CT)失败的主要原因。本文研制了一种新型的近红外/pH双敏感电荷反转多肽纳米复合材料(PDA-PLC)，用于共递送一氧化氮(NO)供体和阿霉素(DOX)。在智能近红外(NIR)照射下，释放的高浓度NO可以抑制P-gp的表达，逆转MDR，并辅助光热疗法(PTT)根除癌细胞而不留下皮肤疤痕。同时，PDA-PLC独特的电荷反转能力显著促进了肿瘤酸微环境(pH 6.8)下的细胞摄取，增强了其在生理环境(pH 7.4)下的稳定性。这种负载DOX的多肽纳米复合材料PDA-PLC/DOX为PTT-NO-CT三联治疗提供了克服MDR的有效策略。
{"title":"Nir/Ph Dual-Sensitive Polypeptide Nanocomposite Charge-Reverse, Generates No for Triple-Combination Therapy to Reverse Cancer Multidrug Resistance","authors":"Yue Ding, Yuxuan Ma, Chang Du, Chenwei Wang, Tingting Chen, Yang Wang, Jin Wang, Yong Yao, Changming Dong","doi":"10.2139/ssrn.3718058","DOIUrl":"https://doi.org/10.2139/ssrn.3718058","url":null,"abstract":"The multidrug resistance (MDR) induced by the overexpression of P-glycoprotein (P-gp) transporters mainly leads to the chemotherapy (CT) failure. Herein, a novel NIR/pH dual-sensitive charge-reversal polypeptide nanocomposite (PDA-PLC) was developed for co-delivering nitric oxide (NO) donor and doxorubicin (DOX). Under intelligent near-infrared (NIR) irradiation, the released high-concentration NO could inhibit the P-gp expression to reverse MDR, and assist photothermal therapy (PTT) to eradicate cancer cells without skin scarring. Meanwhile, the distinctive charge-reversal capacity of PDA-PLC significantly facilitates the cellular uptake at tumor acid microenvironment (pH 6.8) and enhances its stability at physiological environment (pH 7.4). This DOX-loading polypeptide nanocomposites PDA-PLC/DOX provide an effective strategy for the PTT-NO-CT triple-combination therapy to overcome MDR.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"113 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79070231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-23DOI: 10.15587/1729-4061.2020.213724
V. Yatsun, G. Filimonikhin, V. Pirogov, V. Amosov, P. Luzan
A three-mass anti-resonance vibratory machine with a vibration exciter in the form of a passive auto-balancer has been analytically synthesized. In the vibratory machine, platforms 1 and 2 are visco-elastically attached to platform 3. Platform 3 is visco-elastically attached to the base. The motion of loads relative to the auto-balancer housing is hindered by the forces of viscous resistance. A theoretical study has shown that the vibratory machine possesses three resonance frequencies and three corresponding forms of platforms' oscillations. Values for the parameters of supports that ensure the existence of an anti-resonance form of motion have been analytically selected. Under an anti-resonance form, platform 3 is almost non-oscillating while platforms 1 and 2 oscillate in the opposite phase. In the vibratory machine, platform 1 can be active (working), platform 2 will then be reactive (a dynamic vibration damper), and vice versa. At the same time, the vibratory machine will operate when mounting a vibration exciter both on platform 1 and platform 2. An anti-resonance form would occur when the loads get stuck in the vicinity of the second resonance frequency of the platforms' oscillations. Given the specific parameters of the vibratory machine, numerical methods were used to investigate its dynamic characteristics. Numerical calculations have shown the following for the case of small internal and external resistance forces in the vibratory machine: ‒ theoretically, there are seven possible modes of load jam; ‒ the second (anti-resonance) form of platform oscillations is theoretically implemented at load jamming modes 3 and 4; ‒ jamming mode 3 is locally asymptotically stable while load jamming mode 4 is unstable; ‒ for the loads to get stuck in the vicinity of the second resonance frequency, one needs to provide the vibratory machine with the initial conditions close to the jamming mode 3, or smoothly accelerate the rotor to the working frequency; ‒ the dynamic characteristics of the vibratory machine can be controlled in a wide range by changing both the rotor speed and the external and internal forces of viscous resistance. The results reported here are applicable for the design of anti-resonance three-mass vibratory machines for general purposes
{"title":"Research of Antiresonance Three-Mass Vibratory Machine With a Vibration Exciter in the Form of a Passive Auto-Balancer","authors":"V. Yatsun, G. Filimonikhin, V. Pirogov, V. Amosov, P. Luzan","doi":"10.15587/1729-4061.2020.213724","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.213724","url":null,"abstract":"A three-mass anti-resonance vibratory machine with a vibration exciter in the form of a passive auto-balancer has been analytically synthesized. In the vibratory machine, platforms 1 and 2 are visco-elastically attached to platform 3. Platform 3 is visco-elastically attached to the base. The motion of loads relative to the auto-balancer housing is hindered by the forces of viscous resistance. A theoretical study has shown that the vibratory machine possesses three resonance frequencies and three corresponding forms of platforms' oscillations. Values for the parameters of supports that ensure the existence of an anti-resonance form of motion have been analytically selected. Under an anti-resonance form, platform 3 is almost non-oscillating while platforms 1 and 2 oscillate in the opposite phase. In the vibratory machine, platform 1 can be active (working), platform 2 will then be reactive (a dynamic vibration damper), and vice versa. At the same time, the vibratory machine will operate when mounting a vibration exciter both on platform 1 and platform 2. An anti-resonance form would occur when the loads get stuck in the vicinity of the second resonance frequency of the platforms' oscillations. Given the specific parameters of the vibratory machine, numerical methods were used to investigate its dynamic characteristics. Numerical calculations have shown the following for the case of small internal and external resistance forces in the vibratory machine: ‒ theoretically, there are seven possible modes of load jam; ‒ the second (anti-resonance) form of platform oscillations is theoretically implemented at load jamming modes 3 and 4; ‒ jamming mode 3 is locally asymptotically stable while load jamming mode 4 is unstable; ‒ for the loads to get stuck in the vicinity of the second resonance frequency, one needs to provide the vibratory machine with the initial conditions close to the jamming mode 3, or smoothly accelerate the rotor to the working frequency; ‒ the dynamic characteristics of the vibratory machine can be controlled in a wide range by changing both the rotor speed and the external and internal forces of viscous resistance. The results reported here are applicable for the design of anti-resonance three-mass vibratory machines for general purposes","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78937303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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