In this paper, a simple but effective method is proposed to generate a bio-mimic wave propagating motion in a magnetic soft actuator. Two examples, a metachronal wave in artificial cilia and a crawling motion of an artificial caterpillar, are shown as demonstrations. These are kinds of wave propagating motions which are popular in natural systems and are also primitive systems of natural creatures. In the proposed system, an elastic material and a magnetic powder were used to fabricate a flexible magnetic structure. There are 2 essential features in the system; one is periodic arrangement of magnetic anisotropy, and the other is application of a rotating magnetic field. Using this method of wave generation, we realized drastic change in flow making behavior of artificial cilia and a crawling motion very similar to living caterpillars. The proposed system would be useful to enhance the field of the bio-mimic soft robotics.
{"title":"Biomimetic Wave Propagation in Magnetic Soft Actuator","authors":"F. Tsumori, Hayato Shinoda","doi":"10.2139/ssrn.3949874","DOIUrl":"https://doi.org/10.2139/ssrn.3949874","url":null,"abstract":"In this paper, a simple but effective method is proposed to generate a bio-mimic wave propagating motion in a magnetic soft actuator. Two examples, a metachronal wave in artificial cilia and a crawling motion of an artificial caterpillar, are shown as demonstrations. These are kinds of wave propagating motions which are popular in natural systems and are also primitive systems of natural creatures. In the proposed system, an elastic material and a magnetic powder were used to fabricate a flexible magnetic structure. There are 2 essential features in the system; one is periodic arrangement of magnetic anisotropy, and the other is application of a rotating magnetic field. Using this method of wave generation, we realized drastic change in flow making behavior of artificial cilia and a crawling motion very similar to living caterpillars. The proposed system would be useful to enhance the field of the bio-mimic soft robotics.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114384919","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}
Dylan Radovic, L. Kruitwagen, C. S. D. Witt, Ben Caldecott, S. Tomlinson, M. Workman
The energy transition potentially poses an existential risk for major international oil companies (IOCs) if they fail to adapt to low-carbon business models. Projections of energy futures, however, are met with diverging assumptions on its scale and pace, causing disagreement among IOC decision-makers and their stakeholders over what the business model of an incumbent fossil fuel company should be. In this work, we used deep multi-agent reinforcement learning to solve an energy systems wargame wherein players simulate IOC decision-making, including hydrocarbon and low-carbon investments decisions, dividend policies, and capital structure measures, through an uncertain energy transition to explore critical and non-linear governance questions, from leveraged transitions to reserve replacements. Adversarial play facilitated by state-of-the-art algorithms revealed decision-making strategies robust to energy transition uncertainty and against multiple IOCs. In all games, robust strategies emerged in the form of low-carbon business models as a result of early transition-oriented movement. IOCs adopting such strategies outperformed business-as-usual and delayed transition strategies regardless of hydrocarbon demand projections. In addition to maximizing value, these strategies benefit greater society by contributing substantial amounts of capital necessary to accelerate the global low-carbon energy transition. Our findings point towards the need for lenders and investors to effectively mobilize transition-oriented finance and engage with IOCs to ensure responsible reallocation of capital towards low-carbon business models that would enable the emergence of fossil fuel incumbents as future low-carbon leaders.
{"title":"Revealing Robust Oil and Gas Company Macro-Strategies Using Deep Multi-Agent Reinforcement Learning","authors":"Dylan Radovic, L. Kruitwagen, C. S. D. Witt, Ben Caldecott, S. Tomlinson, M. Workman","doi":"10.2139/ssrn.3933996","DOIUrl":"https://doi.org/10.2139/ssrn.3933996","url":null,"abstract":"The energy transition potentially poses an existential risk for major international oil companies (IOCs) if they fail to adapt to low-carbon business models. Projections of energy futures, however, are met with diverging assumptions on its scale and pace, causing disagreement among IOC decision-makers and their stakeholders over what the business model of an incumbent fossil fuel company should be. In this work, we used deep multi-agent reinforcement learning to solve an energy systems wargame wherein players simulate IOC decision-making, including hydrocarbon and low-carbon investments decisions, dividend policies, and capital structure measures, through an uncertain energy transition to explore critical and non-linear governance questions, from leveraged transitions to reserve replacements. Adversarial play facilitated by state-of-the-art algorithms revealed decision-making strategies robust to energy transition uncertainty and against multiple IOCs. In all games, robust strategies emerged in the form of low-carbon business models as a result of early transition-oriented movement. IOCs adopting such strategies outperformed business-as-usual and delayed transition strategies regardless of hydrocarbon demand projections. In addition to maximizing value, these strategies benefit greater society by contributing substantial amounts of capital necessary to accelerate the global low-carbon energy transition. Our findings point towards the need for lenders and investors to effectively mobilize transition-oriented finance and engage with IOCs to ensure responsible reallocation of capital towards low-carbon business models that would enable the emergence of fossil fuel incumbents as future low-carbon leaders.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133677717","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}
Zhiyong Chen, Yue Li, Zhen Liu, D. Liang, Longjiang Deng, Bo Peng
Two-dimensional (2D) van der Waals (vdW) ferromagnets have opened new avenues for manipulating spin at the limits of single or few atomic layers, and for creating unique magneto-exciton devices through the coupling of long-range ferromagnetic (FM) orders and excitons. However, 2D vdW ferromagnets explored so far have rarely possessed exciton behaviors; to date, FM CrI3 have been recently revealed to show ligand-field photoluminescence correlated with FM ordering, but typically with a broad emission peak. Alternatively, many-body excitons have been observed in antiferromagnetic (AFM) NiPS3, but the coupling of excitons with AFM orders is exponentially more difficult, owing to extremely high coercivity. Here, we report a straightforward approach to realize strong coupling of narrow helical emission and FM orders at a low magnetic field in CrI3 through a relatively simple microsphere cavity. We show that the resonant whispering-gallery-modes (WGM) of SiO2 microspheres give rising to a series of strong oscillation helical emissions with a full width at half-maximum (FWHM) of ~5 nm under continuous wave excitation. Reversible magnetic control and coding of helical luminescence with multiwavelength is realized in the range of 950-1100 nm. This work enables plenty of opportunities for creating magnetic encoding lasing for photonic integrated chips.
{"title":"Multi-Wavelength Magnetic Coding of Helical Luminescence in Ferromagnetic 2D Layered CrI 3","authors":"Zhiyong Chen, Yue Li, Zhen Liu, D. Liang, Longjiang Deng, Bo Peng","doi":"10.2139/ssrn.3891800","DOIUrl":"https://doi.org/10.2139/ssrn.3891800","url":null,"abstract":"Two-dimensional (2D) van der Waals (vdW) ferromagnets have opened new avenues for manipulating spin at the limits of single or few atomic layers, and for creating unique magneto-exciton devices through the coupling of long-range ferromagnetic (FM) orders and excitons. However, 2D vdW ferromagnets explored so far have rarely possessed exciton behaviors; to date, FM CrI3 have been recently revealed to show ligand-field photoluminescence correlated with FM ordering, but typically with a broad emission peak. Alternatively, many-body excitons have been observed in antiferromagnetic (AFM) NiPS3, but the coupling of excitons with AFM orders is exponentially more difficult, owing to extremely high coercivity. Here, we report a straightforward approach to realize strong coupling of narrow helical emission and FM orders at a low magnetic field in CrI3 through a relatively simple microsphere cavity. We show that the resonant whispering-gallery-modes (WGM) of SiO2 microspheres give rising to a series of strong oscillation helical emissions with a full width at half-maximum (FWHM) of ~5 nm under continuous wave excitation. Reversible magnetic control and coding of helical luminescence with multiwavelength is realized in the range of 950-1100 nm. This work enables plenty of opportunities for creating magnetic encoding lasing for photonic integrated chips.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134543709","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}
Shamail Ahmed, A. Pokle, M. Bianchini, Simon Schweidler, A. Beyer, T. Brezesinski, J. Janek, K. Volz
Layered Li(Ni1-x-yCoxMny)O2 (NCM, with Ni ≥ 0.8) cathode materials are essential to achieve high energy densities in the next generation of lithium-ion batteries. This increased performance comes at the expense of stability. To extend the materials’ lifetime, it is necessary to understand the role that crystal defects play in the degradation during electrochemical cycling. In this study, NCM851005 (85% Ni) is investigated in the pristine state and after 100 and 200 cycles using scanning transmission electron microscopy (STEM), with the focus being on the defects in the material. The formation of antiphase boundaries (APB) from a dislocation in a pristine sample is proven. After 100 cycles, the APBs’ length and width are enlarged compared to the pristine state. After 200 cycles, APBs further evolve into an intragranular rock salt-like phase, distorting the nearby layered structure. It is suggested that the behavior of APBs plays a critical role in determining the performance of this cathode material with prolonged electrochemical cycling. These findings will help to understand better the role of dislocations and antiphase boundaries with electrochemical cycling, and the role of dopants may then be explored to avoid them.
{"title":"Understanding the Formation of Antiphase Boundaries in Layered Oxide Cathode Materials and Their Evolution Upon Electrochemical Cycling","authors":"Shamail Ahmed, A. Pokle, M. Bianchini, Simon Schweidler, A. Beyer, T. Brezesinski, J. Janek, K. Volz","doi":"10.2139/ssrn.3872943","DOIUrl":"https://doi.org/10.2139/ssrn.3872943","url":null,"abstract":"Layered Li(Ni<sub>1-<i>x</i>-<i>y</i></sub>Co<sub><i>x</i></sub>Mn<sub><i>y</i></sub>)O<sub>2</sub> (NCM, with Ni ≥ 0.8) cathode materials are essential to achieve high energy densities in the next generation of lithium-ion batteries. This increased performance comes at the expense of stability. To extend the materials’ lifetime, it is necessary to understand the role that crystal defects play in the degradation during electrochemical cycling. In this study, NCM851005 (85% Ni) is investigated in the pristine state and after 100 and 200 cycles using scanning transmission electron microscopy (STEM), with the focus being on the defects in the material. The formation of antiphase boundaries (APB) from a dislocation in a pristine sample is proven. After 100 cycles, the APBs’ length and width are enlarged compared to the pristine state. After 200 cycles, APBs further evolve into an intragranular rock salt-like phase, distorting the nearby layered structure. It is suggested that the behavior of APBs plays a critical role in determining the performance of this cathode material with prolonged electrochemical cycling. These findings will help to understand better the role of dislocations and antiphase boundaries with electrochemical cycling, and the role of dopants may then be explored to avoid them.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116248699","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}
M. Alawami, F. Bošković, Jinbo Zhu, Kaikai Chen, Sarah E. Sandler, U. Keyser
Nanopore sensing is an emerging technology that has many biosensing applications ranging from DNA sequencing using biological pores to biomolecular analysis using solid-state pores. Solid-state nanopores that can withstand non-physiological conditions are an attractive choice for biosensing applications. Still, biomolecule interactions with the nanopore surface reduces nanopore reusability and increases usage cost. In this study, we present a protocol for storage and repeated use of glass nanopores lasting up to a few months. We investigated the biosensing capability for 90 quartz glass nanopores with a diameter of 11-18 nm that were fabricated using laser-assisted pipette pulling. Nanopores were assembled into multiple microfluidic chips. The storage protocol allows for repeated use of our nanopore chips for up to 19 weeks. The single-molecule biosensing capability over repeated use cycles was demonstrated by quantitative analysis of a DNA nanostructure designed for detection of short single-stranded DNA oligos.
{"title":"Storage and Cleaning Extend Lifetime of Glass Nanopores for Biosensing","authors":"M. Alawami, F. Bošković, Jinbo Zhu, Kaikai Chen, Sarah E. Sandler, U. Keyser","doi":"10.2139/ssrn.3907624","DOIUrl":"https://doi.org/10.2139/ssrn.3907624","url":null,"abstract":"Nanopore sensing is an emerging technology that has many biosensing applications ranging from DNA sequencing using biological pores to biomolecular analysis using solid-state pores. Solid-state nanopores that can withstand non-physiological conditions are an attractive choice for biosensing applications. Still, biomolecule interactions with the nanopore surface reduces nanopore reusability and increases usage cost. In this study, we present a protocol for storage and repeated use of glass nanopores lasting up to a few months. We investigated the biosensing capability for 90 quartz glass nanopores with a diameter of 11-18 nm that were fabricated using laser-assisted pipette pulling. Nanopores were assembled into multiple microfluidic chips. The storage protocol allows for repeated use of our nanopore chips for up to 19 weeks. The single-molecule biosensing capability over repeated use cycles was demonstrated by quantitative analysis of a DNA nanostructure designed for detection of short single-stranded DNA oligos.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114376239","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}
Summary C–N axially chiral skeletons are ubiquitous in bioactive natural products, pharmaceuticals, and chiral ligands. However, their atroposelective synthesis remains a formidable challenge because of their innate low configurational stability compared with that of well-developed C–C atropisomers. Herein, we report a general and efficient method for accessing C–N atropisomers through an axial-to-axial chirality transfer strategy based on palladium/chiral norbornene cooperative catalysis. The obtained C–N axial chirality originates from the preformed transient C–C axial chirality with high fidelity. A variety of C–N axially chiral phenanthridinones are obtained in excellent enantioselectivities (44 examples, up to >99% ee). This method can be applied for the construction of two stereogenic axes via double atroposelective C–H arylation or further transformation of the products via axial-to-axial diastereoinduction. Additionally, the reaction mechanism and the chirality transfer process are elucidated by density functional theory calculations.
{"title":"An Axial-to-Axial Chirality Transfer Strategy for Atroposelective Construction of C–N Axial Chirality","authors":"Zeshui Liu, Pei-Pei Xie, Yuanda Hua, Chenggui Wu, Yuanyuan Ma, Jiangwei Chen, Hong‐Gang Cheng, Xin Hong, Qianghui Zhou","doi":"10.2139/ssrn.3783402","DOIUrl":"https://doi.org/10.2139/ssrn.3783402","url":null,"abstract":"Summary C–N axially chiral skeletons are ubiquitous in bioactive natural products, pharmaceuticals, and chiral ligands. However, their atroposelective synthesis remains a formidable challenge because of their innate low configurational stability compared with that of well-developed C–C atropisomers. Herein, we report a general and efficient method for accessing C–N atropisomers through an axial-to-axial chirality transfer strategy based on palladium/chiral norbornene cooperative catalysis. The obtained C–N axial chirality originates from the preformed transient C–C axial chirality with high fidelity. A variety of C–N axially chiral phenanthridinones are obtained in excellent enantioselectivities (44 examples, up to >99% ee). This method can be applied for the construction of two stereogenic axes via double atroposelective C–H arylation or further transformation of the products via axial-to-axial diastereoinduction. Additionally, the reaction mechanism and the chirality transfer process are elucidated by density functional theory calculations.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"108 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127114300","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}
K. Arole, Jackson W. Blivin, S. Saha, Xiaofei Zhao, Dustin Holta, A. Sarmah, Huaixuan Cao, M. Radovic, J. Lutkenhaus, Micah J. Green
Molten-salt etching of Ti3AlC2 MAX phase offers a promising route to produce 2D Ti3C2Tz (MXene) nanosheets without the need for hazardous HF. However, molten-salt etching generally results in MXene clays that are not fully exfoliated or water-dispersible, thus preventing nanosheet processing. This occurs because molten-salt etching generally results in a high level of -F terminal functionalities that render the MXene clay hydrophobic. Here, we demonstrate a molten salt (SnF2) etching method that, for the first time, produces water-dispersible Ti3C2Tz nanosheets without the need for HF. In molten salt etching, SnF2 diffuses between the layers during etching to form AlF3 and Sn as byproducts; Sn spheres form internally and separate the layers. The stable, aqueous Ti3C2Tz dispersion yields a ζ potential of -31.7 mV, because of -OH terminal groups introduced by KOH washing. X-ray diffraction and electron microscopy confirm the formation of Ti3C2Tz etched clay with substantial d-spacing as compared to the clay from a traditional HF-process. This work is the first to use molten salt etching to successfully prepare colloidally stable aqueous dispersions of Ti3C2Tz nanosheets. The Ti3C2Tz nanosheet film and clay produced by this method also show excellent specific and areal capacitance and conductivity.
{"title":"Water-Dispersible Ti 3C 2T z MXene Nanosheets by Acid-Free, Molten Salt Etching","authors":"K. Arole, Jackson W. Blivin, S. Saha, Xiaofei Zhao, Dustin Holta, A. Sarmah, Huaixuan Cao, M. Radovic, J. Lutkenhaus, Micah J. Green","doi":"10.2139/ssrn.3802026","DOIUrl":"https://doi.org/10.2139/ssrn.3802026","url":null,"abstract":"Molten-salt etching of Ti3AlC2 MAX phase offers a promising route to produce 2D Ti3C2Tz (MXene) nanosheets without the need for hazardous HF. However, molten-salt etching generally results in MXene clays that are not fully exfoliated or water-dispersible, thus preventing nanosheet processing. This occurs because molten-salt etching generally results in a high level of -F terminal functionalities that render the MXene clay hydrophobic. Here, we demonstrate a molten salt (SnF2) etching method that, for the first time, produces water-dispersible Ti3C2Tz nanosheets without the need for HF. In molten salt etching, SnF2 diffuses between the layers during etching to form AlF3 and Sn as byproducts; Sn spheres form internally and separate the layers. The stable, aqueous Ti3C2Tz dispersion yields a ζ potential of -31.7 mV, because of -OH terminal groups introduced by KOH washing. X-ray diffraction and electron microscopy confirm the formation of Ti3C2Tz etched clay with substantial d-spacing as compared to the clay from a traditional HF-process. This work is the first to use molten salt etching to successfully prepare colloidally stable aqueous dispersions of Ti3C2Tz nanosheets. The Ti3C2Tz nanosheet film and clay produced by this method also show excellent specific and areal capacitance and conductivity.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123536459","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}
Y. Hailemichael, Daniel H Johnson, N. Abdel-Wahab, W. Foo, M. Daher, C. Haymaker, K. Wani, C. Saberian, D. Ogata, S. Bentebibel, Sang T Kim, R. Nurieva, Alexander J F Lazar, Hamzah Abu-Sbeih, Yinghong Wang, V. Trinh, Chrystia M Zobniw, C. Spillson, J. Burks, L. Solis, A. Francisco Cruz, Mario L. Marques-Piubelli, Wei Lu, Brenda D. Melendez, M. Davies, J. Wargo, J. Curry, G. Lizée, C. Yee, P. Hwu, S. Ekmekcioglu, A. Diab
Immune checkpoint blockade (ICB) for cancer is associated with high response rates but also high rates of adverse events. To elucidate the underlying immunobiology, we profiled gene expression in intestinal, colitis, and tumor tissue from ICB-treated patients, with parallel studies in preclinical models, and validated our findings in a review of clinical cohort treated with interleukin-6 blockade. Expression of interleukin-6, neutrophil and chemotactic markers was higher in colitis than in normal intestinal tissue. The genes upregulated in colitis were not upregulated in responding tumors from patients receiving ICB. In murine models, interleukin-6 blockade was associated with improved tumor control and a higher density of CD4/CD8 effector T-cells, with reduced Th17, macrophages, and myeloid cells. In an experimental autoimmune encephalomyelitis (EAE) model with tumors, combined interleukin-6 blockade and ICB enhanced tumor rejection while simultaneously mitigating EAE symptoms versus ICB alone. Interleukin-6 blockade with ICB could de-couple autoimmunity from antitumor immunity.
{"title":"Interleukin-6 Blockade Abrogates Immunotherapy Toxicity and Promotes Tumor Immunity","authors":"Y. Hailemichael, Daniel H Johnson, N. Abdel-Wahab, W. Foo, M. Daher, C. Haymaker, K. Wani, C. Saberian, D. Ogata, S. Bentebibel, Sang T Kim, R. Nurieva, Alexander J F Lazar, Hamzah Abu-Sbeih, Yinghong Wang, V. Trinh, Chrystia M Zobniw, C. Spillson, J. Burks, L. Solis, A. Francisco Cruz, Mario L. Marques-Piubelli, Wei Lu, Brenda D. Melendez, M. Davies, J. Wargo, J. Curry, G. Lizée, C. Yee, P. Hwu, S. Ekmekcioglu, A. Diab","doi":"10.2139/ssrn.3808296","DOIUrl":"https://doi.org/10.2139/ssrn.3808296","url":null,"abstract":"Immune checkpoint blockade (ICB) for cancer is associated with high response rates but also high rates of adverse events. To elucidate the underlying immunobiology, we profiled gene expression in intestinal, colitis, and tumor tissue from ICB-treated patients, with parallel studies in preclinical models, and validated our findings in a review of clinical cohort treated with interleukin-6 blockade. Expression of interleukin-6, neutrophil and chemotactic markers was higher in colitis than in normal intestinal tissue. The genes upregulated in colitis were not upregulated in responding tumors from patients receiving ICB. In murine models, interleukin-6 blockade was associated with improved tumor control and a higher density of CD4/CD8 effector T-cells, with reduced Th17, macrophages, and myeloid cells. In an experimental autoimmune encephalomyelitis (EAE) model with tumors, combined interleukin-6 blockade and ICB enhanced tumor rejection while simultaneously mitigating EAE symptoms versus ICB alone. Interleukin-6 blockade with ICB could de-couple autoimmunity from antitumor immunity.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115350513","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}
Shin-Ho Kim-Lee, Pablo Mauleón Pérez, R. Gómez Arrayás, J. Carretero
We describe a dual strategy in Cu catalysis based on an unprecedented dynamic multiligand coordination pool that enables cooperative closed/open shell pathways. This strategy has been applied to address a restricting limitation inherent to Cu-catalyzed B2(pin)2-carboboration of alkynes: conventional methods usually fail with alkyl electrophiles other than simple primary halides due to the very low reactivity of the intermediate vinyl-Cu(I) species. The crossover strategy enabled by ligand exchange in an organometallic intermediate overcomes this reactivity issue, thus expanding the scope of carboboration to unactivated secondary alkyl halides and opening new avenues to access of stereodefined tetrasubstituted vinylboronates. The method is regio- and stereoselective, shows excellent functional group tolerance, and allows the incorporation of complex carbo- and heterocyclic fragments at either reaction partner.
我们描述了一种基于前所未有的动态多配体配位池的Cu催化双策略，该策略使合作的闭/开壳途径成为可能。该策略已被应用于解决cu催化的炔的B2(pin)2-碳硼化的固有限制:由于中间乙烯基- cu (I)的反应活性非常低，除了简单的伯卤化物外，传统的方法通常不能用于烷基亲电试剂。在有机金属中间体中通过配体交换实现的交叉策略克服了这一反应性问题，从而将碳硼化的范围扩大到未活化的仲烷基卤化物，并为获得立体定位的四取代乙烯基硼酸盐开辟了新的途径。该方法具有区域选择性和立体选择性，具有良好的官能团耐受性，并允许在任何反应伙伴处加入复杂的碳环和杂环片段。
{"title":"Dynamic Multiligand Catalysis: A Closed/Open Shell Crossover Strategy Expands Alkyne Carboboration to Unactivated Secondary Alkyl Halides","authors":"Shin-Ho Kim-Lee, Pablo Mauleón Pérez, R. Gómez Arrayás, J. Carretero","doi":"10.2139/SSRN.3777471","DOIUrl":"https://doi.org/10.2139/SSRN.3777471","url":null,"abstract":"We describe a dual strategy in Cu catalysis based on an unprecedented dynamic multiligand coordination pool that enables cooperative closed/open shell pathways. This strategy has been applied to address a restricting limitation inherent to Cu-catalyzed B2(pin)2-carboboration of alkynes: conventional methods usually fail with alkyl electrophiles other than simple primary halides due to the very low reactivity of the intermediate vinyl-Cu(I) species. The crossover strategy enabled by ligand exchange in an organometallic intermediate overcomes this reactivity issue, thus expanding the scope of carboboration to unactivated secondary alkyl halides and opening new avenues to access of stereodefined tetrasubstituted vinylboronates. The method is regio- and stereoselective, shows excellent functional group tolerance, and allows the incorporation of complex carbo- and heterocyclic fragments at either reaction partner.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127432343","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}
Covalent organic framework (COF) is a prominent class of nanoporous materials under consideration for vehicular methane storage. However, evaluating a COF for its methane capacity involves multiple experimental or computational steps, which is expensive and time consuming. Consequently, the discovery of high-capacity COFs for methane storage is very slow. Here we developed equations for super-fast prediction of deliverable methane capacities of COFs from a small number (3 to 7) of physically meaningful and measurable crystallographic features. We provided a set of equations with different fidelities for on-demand predictions based on the accessibility of crystallographic features. We found that an equation with only three crystallographic primary features, as variables, can predict deliverable capacities of 84,800 COFs with a root-mean-square error (RMSE) of 10 cm3 (standard temperature and pressure, STP) cm-3 and mean absolute percentage error (MAPE) of 5%. However, the highest fidelity equation developed here contains seven crystallographic primary features of COFs with RMSE and MAPE of 8.1 cm3 (STP) cm-3 and 4.2%, respectively. With that, we predicted methane storage capacities of 468,343 previously unexplored COFs using the highest fidelity equation and identified several hundred promising candidates with record-setting performance. CUBE_PBB_BA2, a hypothetical COF not yet synthesized, sets the new record of balancing gravimetric (0.396 g g-1) and volumetric (221 cm3 (STP) cm-3) deliverable methane storage capacities under the pressure swing between 65 and 5.8 bar at 298K. Also, 3D-HNU5, a previously synthesized COF, has shown the potential to achieve the gravimetric and volumetric methane storage U.S. Department of Energy target (0.5 g g-1 and 315 cm3 (STP) cm-3) simultaneously with uptakes of 0.755 g g-1 and 334 cm3 (STP) cm-3 at 100 bar/270 K.
{"title":"Machine Learning-Guided Equations for Super-Fast Prediction of Methane Storage Capacities of COFs","authors":"Alauddin Ahmed","doi":"10.2139/ssrn.3751765","DOIUrl":"https://doi.org/10.2139/ssrn.3751765","url":null,"abstract":"Covalent organic framework (COF) is a prominent class of nanoporous materials under consideration for vehicular methane storage. However, evaluating a COF for its methane capacity involves multiple experimental or computational steps, which is expensive and time consuming. Consequently, the discovery of high-capacity COFs for methane storage is very slow. Here we developed equations for super-fast prediction of deliverable methane capacities of COFs from a small number (3 to 7) of physically meaningful and measurable crystallographic features. We provided a set of equations with different fidelities for on-demand predictions based on the accessibility of crystallographic features. We found that an equation with only three crystallographic primary features, as variables, can predict deliverable capacities of 84,800 COFs with a root-mean-square error (RMSE) of 10 cm3 (standard temperature and pressure, STP) cm-3 and mean absolute percentage error (MAPE) of 5%. However, the highest fidelity equation developed here contains seven crystallographic primary features of COFs with RMSE and MAPE of 8.1 cm3 (STP) cm-3 and 4.2%, respectively. With that, we predicted methane storage capacities of 468,343 previously unexplored COFs using the highest fidelity equation and identified several hundred promising candidates with record-setting performance. CUBE_PBB_BA2, a hypothetical COF not yet synthesized, sets the new record of balancing gravimetric (0.396 g g-1) and volumetric (221 cm3 (STP) cm-3) deliverable methane storage capacities under the pressure swing between 65 and 5.8 bar at 298K. Also, 3D-HNU5, a previously synthesized COF, has shown the potential to achieve the gravimetric and volumetric methane storage U.S. Department of Energy target (0.5 g g-1 and 315 cm3 (STP) cm-3) simultaneously with uptakes of 0.755 g g-1 and 334 cm3 (STP) cm-3 at 100 bar/270 K.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121255084","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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