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Effects of Bi addition on Si features, tensile properties and wear resistance of hypereutectic Al-15Si alloy

IOP Conference Series: materials science and engineering 2020年第1期861卷

作者： C L Pereira L F Gomes J E Spinelli Department of Materials Engineering Federal University of São Carlos São Carlos SP 13565-905 Brazil Federal University of São Carlos Graduate Program in Materials Science and Engineering 13565-905 - São Carlos SP Brazil

Al-Si alloys are very important in the automotive industry. This is thanks to their high strength to weight ratio, suitable fluidity, good corrosion resistance and high productivity. The shape of the eutectic Silicon (Si) has been widely studied since it is considered an index of quality regarding many application properties. Understanding the effects of alloy additions on the morphology of Si has drawn researcher's attention. One of these elements of interest is Bismuth (Bi), which may be part of the composition of Al-Si alloys either as an addictive or a contamination. Hence, the microstructure aspects related to the presence of Bi are important requiring further consideration. In the present study, Al-15wt% Si hypereutectic alloy is modified with 1.0 wt% Bi. The goal is to compare the effect of this addition on the morphology of the phases forming the microstructure and on tensile/wear properties. In order to pursue that comparison, previously available data for the binary Al-15wt% Si alloy will be used. Various samples characterized by distinct cooling rates were generated by transient directional solidification of the ternary Al-Si-Bi alloy. The experimental variations of the eutectic spacing will be compared to each other based on their trends. It was found that the addition of minor Bi content (∼1%) permitted tensile strength and ductility of 195 MPa and 14%. Furthermore, wear resistance was improved thanks to Bi. The reasons for that will be outlined.

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Evaluation of phase formation and physical-mechanical properties of Portland cements produced with civil construction waste

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CEMENT 2021年 5卷

作者： F.N. Costa D.V. Ribeiro Post-Graduate Program in Civil Engineering (PPEC)/Federal University of Bahia Rua Aristides Novis 02. Federação Salvador BA 40210-630 Brazil Department of Materials Science and Technology Federal University of Bahia Rua Aristides Novis 02. Federação Salvador BA 40210-630 Brazil

Cement is the most widely used building material worldwide. Its production demands a large amount of natural resources, in addition to high energy consumption. Thus, the cement industry has been looking for solutions that effectively reduce the use of these resources as well as greenhouse gas emissions. This research aims to show the technical feasibility of incorporating civil construction waste (CCW) in the production of Portland cement. To this purpose, the physicochemical characterization of the raw materials used was carried out, dosage and manufacture of the raw mix, which were calcined at 1450 °C. Clinkers were characterized mineralogically, by means of XRD, to verify the formation of the crystalline phases. Subsequently, the clinkers were ground, resulting in Portland cements, and their physical-mechanical properties were evaluated. The results showed the potential of using CCW as an alternative raw material, since experimental cements presented performance similar to industrial cements used as a reference.

关键词： Civil construction waste (CCW Reuse Environment Cement Compressive strength

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Mixed-linker strategy for suppressing structural flexibility of metal-organic framework membranes for gas separation

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Communications Chemistry 2023年第1期6卷 1-12页

作者： Chung-Kai Chang Yen-Chun Lin Yi-Pei Li Dun-Yen Kang Ting-Rong Ko Tsai-Yu Lin Heng-Liang Wu Hyun Jung Yu Jong Suk Lee Department of Chemical Engineering National Taiwan University No. 1 Sec. 4 Roosevelt Road Taipei 10617 Taiwan International Graduate Program of Molecular Science and Technology National Taiwan University (NTU-MST) No. 1 Sec. 4 Roosevelt Road Taipei 10617 Taiwan Center of Atomic Initiative for New Materials National Taiwan University No. 1 Sec. 4 Roosevelt Road Taipei 10617 Taiwan Center for Condensed Matter Sciences National Taiwan University No. 1 Sec. 4 Roosevelt Road Taipei 10617 Taiwan Department of Chemical and Biomolecular Engineering Sogang University Baekbeom-ro 35 Mapo-gu Seoul 04107 Republic of Korea

Structural flexibility is a critical issue that limits the application of metal-organic framework (MOF) membranes for gas separation. Herein we propose a mixed-linker approach to suppress the structural flexibility of the CAU-10-based (CAU = Christian-Albrechts-University) membranes. Specifically, pure CAU-10-PDC membranes display high separation performance but at the same time are highly unstable for the separation of CO2/CH4. A partial substitution (30 mol.%) of the linker PDC with BDC significantly improves its stability. Such an approach also allows for decreasing the aperture size of MOFs. The optimized CAU-10-PDC-H (70/30) membrane possesses a high separation performance for CO2/CH4(separation factor of 74.2 and CO2permeability of 1,111.1 Barrer under 2 bar of feed pressure at 35°C). A combination of in situ characterization with X-ray diffraction (XRD) and diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, as well as periodic density functional theory (DFT) calculations, unveils the origin of the mixed-linker approach to enhancing the structural stability of the mixed-linker CAU-10-based membranes during the gas permeation tests.

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Overcoming small-bandgap charge recombination in visible and NIR-light-driven hydrogen evolution by engineering the polymer photocatalyst structure

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Nature communications 2024年第1期15卷 707页

作者： Mohamed Hammad Elsayed Mohamed Abdellah Ahmed Zaki Alhakemy Islam M A Mekhemer Ahmed Esmail A Aboubakr Bo-Han Chen Amr Sabbah Kun-Han Lin Wen-Sheng Chiu Sheng-Jie Lin Che-Yi Chu Chih-Hsuan Lu Shang-Da Yang Mohamed Gamal Mohamed Shiao-Wei Kuo Chen-Hsiung Hung Li-Chyong Chen Kuei-Hsien Chen Ho-Hsiu Chou Department of Chemistry Faculty of Science Al-Azhar University Nasr City 11884 Cairo Egypt. Institute of Atomic and Molecular Sciences Academia Sinica Taipei 10617 Taiwan. Center for Condensed Matter Sciences National Taiwan University Taipei 10617 Taiwan. Department of Chemical Engineering National Tsing Hua University Hsinchu 300044 Taiwan. Department of Chemistry United Arab Emirates University Al Ain P.O. Box 15551 United Arab Emirates. Department of Chemistry Qena Faculty of Science South Valley University 83523 Qena Egypt. Chemical Physics and NanoLund Lund University 22100 Lund Sweden. Chemistry Department Faculty of Science Al-Azhar University Assiut 71542 Egypt. Sustainable Chemical Science and Technology Taiwan International Graduate Program Taipei Taiwan. Department of Applied Chemistry National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan. Institute of Chemistry Academia Sinica 128 Sec 2 Academia Rd. Nankang Taipei 11529 Taiwan. Institute of Photonics Technologies National Tsing Hua University Hsinchu 300044 Taiwan. Center of Atomic Initiative for New Materials National Taiwan University Taipei 10617 Taiwan. Department of Chemical Engineering National Chung Hsing University Taichung 40227 Taiwan. Department of Materials and Optoelectronic Science Center for Functional Polymers and Supramolecular Materials National Sun Yat-Sen University Kaohsiung 804 Kaohsiung Taiwan. Department of Physics National Taiwan University Taipei 10617 Taiwan. Department of Chemical Engineering National Tsing Hua University Hsinchu 300044 Taiwan. hhchou@mx.nthu.edu.tw.

Designing an organic polymer photocatalyst for efficient hydrogen evolution with visible and near-infrared (NIR) light activity is still a major challenge. Unlike the common behavior of gradually increasing the charge recombination while shrinking the bandgap, we present here a series of polymer nanoparticles (Pdots) based on ITIC and BTIC units with different π-linkers between the acceptor-donor-acceptor (A-D-A) repeated moieties of the polymer. These polymers act as an efficient single polymer photocatalyst for H2 evolution under both visible and NIR light, without combining or hybridizing with other materials. Importantly, the difluorothiophene (ThF) π-linker facilitates the charge transfer between acceptors of different repeated moieties (A-D-A-(π-Linker)-A-D-A), leading to the enhancement of charge separation between D and A. As a result, the PITIC-ThF Pdots exhibit superior hydrogen evolution rates of 279 µmol/h and 20.5 µmol/h with visible (>420 nm) and NIR (>780 nm) light irradiation, respectively. Furthermore, PITIC-ThF Pdots exhibit a promising apparent quantum yield (AQY) at 700 nm (4.76%).

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AAA + ATPase Thorase inhibits mTOR signaling through the disassembly of the mTOR complex 1

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Nature Communications 2022年第1期13卷 4836页

作者： Umanah, George K. E. Abalde-Atristain, Leire Khan, Mohammed Repon Mitra, Jaba Dar, Mohamad Aasif Chang, Melissa Tangella, Kavya McNamara, Amy Bennett, Samuel Chen, Rong Aggarwal, Vasudha Cortes, Marisol Worley, Paul F. Ha, Taekjip Dawson, Ted M. Dawson, Valina L. Neuroregeneration and Stem Cell Programs Institute for Cell Engineering Johns Hopkins University School of Medicine Baltimore 21205 MD United States Department of Neurology Johns Hopkins University School of Medicine Baltimore 21205 MD United States Cellular and Molecular Medicine Graduate Program Johns Hopkins University School of Medicine Baltimore 21205 MD United States Department of Materials Science and Engineering University of Illinois at Urbana-Champaign Urbana 61801 IL United States Department of Biophysics and Biophysical Chemistry Johns Hopkins University Baltimore 21205 MD United States Solomon H. Snyder Department of Neuroscience Johns Hopkins University School of Medicine Baltimore 21205 MD United States Departments of Biophysics and Biophysical Chemistry Biophysics and Biomedical Engineering JHU Howard Hughes Medical Institute Baltimore 21205 MD United States Department of Pharmacology and Molecular Sciences Johns Hopkins University School of Medicine Baltimore 21205 MD United States Department of Physiology Johns Hopkins University School of Medicine Baltimore 21205 MD United States Division of Neuroscience National Institute of Neurological Disorders and Stroke National Institutes of Health Bethesda MD United States Vollum Institute Oregon Health & Science University Portland 97239 OR United States

The mechanistic target of rapamycin (mTOR) signals through the mTOR complex 1 (mTORC1) and the mTOR complex 2 to maintain cellular and organismal homeostasis. Failure to finely tune mTOR activity results in metabolic dysregulation and disease. While there is substantial understanding of the molecular events leading mTORC1 activation at the lysosome, remarkably little is known about what terminates mTORC1 signaling. Here, we show that the AAA + ATPase Thorase directly binds mTOR, thereby orchestrating the disassembly and inactivation of mTORC1. Thorase disrupts the association of mTOR to Raptor at the mitochondria-lysosome interface and this action is sensitive to amino acids. Lack of Thorase causes accumulation of mTOR-Raptor complexes and altered mTORC1 disassembly/re-assembly dynamics upon changes in amino acid availability. The resulting excessive mTORC1 can be counteracted with rapamycin in vitro and in vivo. Collectively, we reveal Thorase as a key component of the mTOR pathway that disassembles and thus inhibits mTORC1. © 2022, The Author(s).

关键词： Cell signalling Lysosomes Mechanisms of disease

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Current md forcefields fail to capture key features of protein structure and fluctuations: a case study of cyclophilin a and t4 lysozyme

arXiv

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arXiv 2020年

作者： Mei, Zhe Grigas, Alex T. Treado, John D. Corres, Gabriel Melendez Vuorte, Maisa Sammalkorpi, Maria Regan, Lynne Levine, Zachary A. O’Hern, Corey S. Department of Chemistry Yale University New HavenCT06520 United States Integrated Graduate Program in Physical and Engineering Biology Yale University New HavenCT06520 United States Graduate Program in Computational Biology and Bioinformatics Yale University New HavenCT06520 United States Department of Mechanical Engineering and Materials Science Yale University New HavenCT06520 United States Department of Biology UPR Humacao Puerto RicoHumacao00792 Puerto Rico Department of Chemistry and Materials Science School of Chemical Engineering Aalto University Aalto Finland Department of Bioproducts and Biosystems School of Chemical Engineering Aalto University Aalto Finland Institute of Quantitative Biology Biochemistry and Biotechnology Center for Synthetic and Systems Biology School of Biological Sciences University of Edinburgh Edinburgh United Kingdom Department of Pathology Yale School of Medicine New HavenCT06520 United States Department of Molecular Biophysics and Biochemistry Yale University New HavenCT06520 United States Department of Physics Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States

Globular proteins undergo thermal fluctuations in solution, while maintaining an overall well-defined folded structure. In particular, studies have shown that the core structure of globular proteins differs in small, but significant ways when they are solved by x-ray crystallography versus solution-based NMR spectroscopy. Given these discrepancies, it is unclear whether molecular dynamics (MD) simulations can accurately recapitulate protein conformations. We therefore perform extensive MD simulations across multiple force fields and sampling techniques to investigate the degree to which computer simulations can capture the ensemble of conformations observed in experiments. By analyzing fluctuations in the atomic coordinates and core packing, we show that conformations sampled in MD simulations both move away from and sample a larger conformational space than the ensemble of structures observed in NMR experiments. However, we find that adding inter-residue distance restraints that match those obtained via Nuclear Overhauser Effect measurements enables the MD simulations to sample more NMR-like conformations, though significant differences between the core packing features in restrained MD and the NMR ensemble remain. Given that the protein structures obtained from the MD simulations possess smaller and less dense protein cores compared to those solved by NMR, we suggest that future improvements to MD forcefields should aim to increase the packing of hydrophobic residues in protein cores. © 2020, CC BY.

关键词： Molecular dynamics

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Recent advances in molecularly imprinted polymers toward biomedical healthcare devices

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Biosensors & bioelectronics 2025年 287卷 117637页

作者： Youngjun Seo Yonghwan Kim Jaeheung Kim Hyo Gi Jung Jae Won Jang Hyunji Kim Kyo Seon Hwang Dongtak Lee Sang Won Lee Jeong Hoon Lee Dae Sung Yoon School of Biomedical Engineering Korea University Seoul 02841 Republic of Korea Interdisciplinary Program in Precision Public Health Korea University Seoul 02841 Republic of Korea. Department of Clinical Pharmacology and Therapeutics College of Medicine Kyung Hee University Seoul 02447 Republic of Korea. Department of Bioengineering & Nano-bioengineering Research Center for Bio Materials and Process Development Incheon National University Incheon 22012 Republic of Korea Division of Bioengineering Incheon National University Incheon 22012 Republic of Korea. Terasaki Institute for Biomedical Innovation Los Angeles CA 90064 USA. Electronic address: skylsw5@korea.ac.kr. KU-KIST Graduate School of Converging Science and Technology Korea University Seoul 02841 Republic of Korea Department of Integrative Energy Engineering College of Engineering Korea University Seoul 02841 Republic of Korea. Electronic address: hellojhlee@korea.ac.kr. Interdisciplinary Program in Precision Public Health Korea University Seoul 02841 Republic of Korea Astrion Inc Seoul 02841 Republic of Korea. Electronic address: dsyoon@korea.ac.kr.

Following the increase in the global aging population, the importance of monitoring various disease-related biomarkers at an early stage has increased to ensure the health of the elderly. In an aging society, point-of-care (POC) systems are needed to care for elderly people who have physical and mental disorders. In light of the increasing prominence of POC systems, there is a growing effort to address the limitations associated with conventional receptors in wearable devices by substituting them with molecularly imprinted polymer (MIP). MIPs are well-known synthetic receptors engineered with specific binding cavities based on the "lock and key" principle. They could be synthesized in various configurations depending on specific types of monomers and templates. Compared to conventional receptors such as antibodies and aptamers, MIPs exhibit outstanding advantages, including good stability, cost-effectiveness, ease of synthesis, reusability, and broad applicability. These advantages have led to their extensive application in biomedical healthcare devices. This review summarizes a comparative analysis of sensors utilized for the detection of disease-specific biomarkers through diverse MIP applications and methodologies. Furthermore, we evaluated recent advancements in the miniaturization of MIPs and their integration with wearable biomedical devices for comprehensive healthcare monitoring applications. Finally, we delineated the existing limitations that need to be surmounted for the effective implementation of MIP-based biomedical devices and outlined future objectives for the enhancement of wearable and wireless biomedical healthcare monitoring devices.

关键词： Biomarker Healthcare monitoring Molecularly imprinted polymer Point-of-care Wearable biomedical devices

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Dielectric Nanospheres: Directional Modulation of Exciton Emission Using Single Dielectric Nanospheres (Adv. Mater. 20/2021)

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Advanced materials 2021年第20期33卷

作者： Jie Fang Mingsong Wang Kan Yao Tianyi Zhang Alex Krasnok Taizhi Jiang Junho Choi Ethan Kahn Brian A. Korgel Mauricio Terrones Xiaoqin Li Andrea Alù Yuebing Zheng Walker Department of Mechanical Engineering and Texas Materials Institute The University of Texas at Austin Austin TX 78712 USA Photonics Initiative Advanced Science Research Center City University of New York New York NY 10031 USA Department of Materials Science and Engineering Department of Physics Department of Chemistry and Center for 2-Dimensional and Layered Materials The Pennsylvania State University University Park PA 16802 USA McKetta Department of Chemical Engineering The University of Texas at Austin Austin TX 78712 USA Department of Physics The University of Texas at Austin Austin TX 78712 USA Physics Program Graduate Center City University of New York New York NY 10016 USA

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Self-assembled periodic nanostructures using martensitic phase transformations

arXiv

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arXiv 2020年

作者： Prakash, Abhinav Wang, Tianqi Bucsek, Ashley Truttmann, Tristan K. Fali, Alireza Cotrufo, Michele Yun, Hwanhui Kim, Jong-Woo Ryan, Philip J. Mkhoyan, K. Andre Alù, Andrea Abate, Yohannes James, Richard D. Jalan, Bharat Department of Chemical Engineering and Materials Science University of Minnesota – Twin Cities MinneapolisMN55455 United States Department of Aerospace Engineering and Mechanics University of Minnesota – Twin Cities MinneapolisMN55455 United States Department of Mechanical Engineering University of Michigan Ann ArborMI48109 United States Department of Physics and Astronomy University of Georgia AthensGA30602 United States Photonics Initiative Advanced Science Research Center City University of New York NY10031 United States Advanced Photon Source Argonne National Laboratory ArgonneIL60439 United States Physics Program Graduate Center City University of New York New YorkNY10016 United States

We describe a novel approach for the rational design and synthesis of self-assembled periodic nanostructures using martensitic phase transformations. We demonstrate this approach in a thin film of perovskite SrSnO3 with reconfigurable periodic nanostructures consisting of regularly spaced regions of sharply contrasted dielectric properties. The films can be designed to have different periodicities and relative phase fractions via chemical doping or strain engineering. The dielectric contrast within a single film can be tuned using temperature and laser wavelength, effectively creating a variable photonic crystal. Our results show the realistic possibility of designing large-area self-assembled periodic structures using martensitic phase transformations with the potential of implementing "built-to-order" nanostructures for tailored optoelectronic functionalities. Copyright © 2020, The Authors. All rights reserved.

关键词： Thin films

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Frontispiece: Optical Characteristics of Hybrid Macrocycles with Dithienogermole and Tricoordinate Boron Units

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Chemistry – A European Journal 2021年第10期27卷

作者： Dr. Yohei Adachi Taishi Nabeya Keigo Kawakami Kosuke Yamaji Prof. Dr. Frieder Jäkle Prof. Dr. Joji Ohshita Applied Chemistry Program Graduate School of Advanced Science and Engineering Hiroshima University Higashi-Hiroshima 739-8527 Japan Department of Chemistry Rutgers University-Newark Newark NJ 07102 USA Division of Materials Model-Based Research Digital Monozukuri (Manufacturing) Education and Research Center Hiroshima University Higashi-Hiroshima 739-0046 Japan

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