As the initially discovered allotrope of boron, amorphous elementary boron (AE-B) has been reported for more than two centuries. Several possible structures of AE-B have been proposed during the past decades. Due to its noncrystalline nature, however, the structure of AE-B has not yet been determined. We notice that AE-B can be dissolved in organic solvents, although the solubility is very low. After surface adsorption from solution, the individual or the self-assembled structure of AE-B molecules can be characterized at the single-molecule or nanoscopic level, which may be helpful to reveal the molecular structure of AE-B. Atomic force microscopy (AFM) imaging shows that AE-B is a chain-like molecule with a thickness (or height) of 0.17 ± 0.01 nm, which agrees well with the diameter of a B atom, demonstrating that the structure of an AE-B molecule contains only one layer of B atoms. Results from high-resolution transmission electron microscopy (HRTEM) indicate that AE-B molecules can be self-assembled into a nanosheet with parallel lines. The width of each line is 0.27 nm, and the periodical length along the chain axial direction is 0.32 ± 0.01 nm. These results indicate that AE-B is composed of a ladder-like inorganic polymer with B as the structural unit. This conclusion is supported by the single-chain elasticity obtained by single-molecule AFM and quantum mechanical calculations. We expect that this fundamental study is not only an ending of the two-century-old scientific mystery but also the beginning of the research and applications of AE-B (ladder B) as a polymeric material. The research strategy may be also used to study other amorphous inorganic materials.
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http://dx.doi.org/10.1021/acsnano.3c03055 | DOI Listing |
Sci Rep
November 2024
School of Civil Engineering, Inner Mongolia University of Science and Technology, Baotou, 014010, Inner Mongolia, China.
Due to the unique geographical environment of the plateau, large-scale damage and destruction of fractured surrounding rock often occur during geotechnical engineering construction as a result of high-temperature cycles. Therefore, this study aims to investigate the mechanical properties and damage characteristics of fractured granite under the influence of cyclic temperature, uniaxial compression tests were conducted on granite specimens with pre-existing fractures at cyclic temperatures of 30 °C, 50 °C, 70 °C, 100 °C, and 130 °C. The study integrated analyses of characteristic stress, acoustic emission parameters, damage variables, fractal dimensions, and SEM to explore the mechanical properties and damage features of granite.
View Article and Find Full Text PDFCurr HIV Res
November 2024
Department of AIDS Research, Hebei Key Laboratory of Pathogen and Epidemiology of Infectious Disease, Hebei Provincial Center for Disease Control and Prevention, Shijiazhuang, Hebei, 050021, China.
Background: In the Hebei province, Human Immunodeficiency Virus type one (HIV-1) recombinant strains of subtypes B, C, and CRF01_AE are emerging very rapidly and diversely.
Objective: In order to confirm the characteristics of novel recombination forms, we aimed to analyze HIV-1 Near-full-length Genome sequences (NFLGs) obtained from three Men who have Sex with Men (MSM) in this study.
Methods: Phylogenetic trees were constructed and breakpoints analysis were performed based on the NFLGs and each gene fragment to examine the gene recombination patterns of three new HIV-1 NFLGs.
ACS Nano
June 2023
School of Chemistry, Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest Jiaotong University, Chengdu 610031, People's Republic of China.
As the initially discovered allotrope of boron, amorphous elementary boron (AE-B) has been reported for more than two centuries. Several possible structures of AE-B have been proposed during the past decades. Due to its noncrystalline nature, however, the structure of AE-B has not yet been determined.
View Article and Find Full Text PDFAIDS Res Ther
May 2023
Department of AIDS Research, Hebei Key Laboratory of Pathogen and Epidemiology of Infectious Disease, Hebei Provincial Center for Disease Control and Prevention, Shijiazhuang, Hebei, China.
Background: Homosexual contact is the main route of human immunodeficiency virus type one (HIV-1) transmission in Cangzhou Prefecture, Hebei, China. Moreover, the number of circulating recombinant forms (CRFs) and unique recombinant forms (URFs) in this key population is ever increasing.
Methods: In this study, we identified two novel URFs (hcz0017 and hcz0045) from two men who have sex with men (MSM) based in Cangzhou Prefecture.
Front Microbiol
May 2022
NHC Key Laboratory of AIDS Immunology (China Medical University), National Clinical Research Center for Laboratory Medicine, The First Affiliated Hospital of China Medical University, Shenyang, China.
The transmission of Unique Recombinant Forms (URFs) has complicated the molecular epidemic of HIV-1. This increasing genetic diversity has implications for prevention surveillance, diagnosis, and vaccine design. In this study, we characterized the HIV-1 URFs from 135 newly diagnosed HIV-1 infected cases between 2016 and 2020 in Shenyang, northeast China and analyzed the evolutionary relationship of them by phylogenetic and recombination approaches.
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