A new design scheme for ultrafast transmission electron microscopy (UTEM) has been developed based on a Schottky-type field emission gun (FEG) at the Institute of Physics, Chinese Academy of Sciences (IOP CAS). In this UTEM setup, electron pulse emission is achieved by integrating a laser port between the electron gun and the column and the resulting microscope can operate in either continuous or pulsed mode. In pulsed mode, the optimized electron beam properties are an energy width of ~0.65 eV, micrometer-scale coherence lengths and sub-picosecond pulse durations. The potential applications of this UTEM, which include electron diffraction, high-resolution imaging, electron energy loss spectroscopy, and photon-induced near-field electron microscopy, are demonstrated using ultrafast electron pulses. Furthermore, we use a nanosecond laser (~10 ns) to show that the laser-driven FEG can support high-quality TEM imaging and electron holography when using a stroboscopic configuration. Our results also indicate that FEG-based ultrafast electron sources may enable high-performance analytical UTEM.
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http://dx.doi.org/10.1016/j.ultramic.2019.112887 | DOI Listing |
Sci Rep
January 2025
Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC-CONICET), Fundación para Investigaciones Biológicas Aplicadas (FIBA), Mar del Plata, 7600, Argentina.
The fungal green synthesis of nanoparticles (NPs) has gained great interest since it is a cost-effective and easy handling method. The process is simple because fungi secrete metabolites and proteins capable of reducing metal salts in aqueous solution, however the mechanism remains largely unknown. The aim of this study was to analyze the secretome of a Trichoderma harzianum strain during the mycobiosynthesis process of zinc and iron nanoparticles.
View Article and Find Full Text PDFMikrochim Acta
January 2025
Department of Analytical Chemistry, Faculty of Pharmacy, "Iuliu Hațieganu" University of Medicine and Pharmacy, 4 Pasteur Street, 400349, Cluj-Napoca, Romania.
A label-free, flexible, and disposable aptasensor was designed for the rapid on-site detection of vancomycin (VAN) levels. The electrochemical sensor was based on lab-printed carbon electrodes (C-PE) enriched with cauliflower-shaped gold nanostructures (AuNSs), on which VAN-specific aptamers were immobilized as biorecognition elements and short-chain thiols as blocking agents. The AuNSs, characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), enhanced the electrochemical properties of the platform and the aptamer immobilization active sites.
View Article and Find Full Text PDFApoptosis
January 2025
Department of Cardiac Surgery, First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan II Rd, Guangzhou, 510080, China.
Recent studies have suggested that sVEGFR3 is involved in cardiac diseases by regulating lymphangiogenesis; however, results are inconsistent. The aim of this study was to investigate the function and mechanism of sVEGFR3 in myocardial ischemia/reperfusion injury (MI/RI). sVEGFR3 effects were evaluated in vivo in mice subjected to MI/RI, and in vitro using HL-1 cells exposed to oxygen-glucose deprivation/reperfusion.
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January 2025
Environmental and Occupational Hazards Control Research Center, Research Institute for Health Sciences and Environment, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
The magnetic material Nd2Fe14B is one of the strongest magnetic materials found in nature. The demand for the production of these nanoparticles is significantly high due to their exceptional properties. The aim of the present study is to synthesize magnetic nanoparticles of Nd2Fe14B using ethanol in the wet ball milling technique (WBMT).
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January 2025
Department of Pharmaceutical Chemistry, Semmelweis University, Hőgyes Endre U. 9, 1092, Budapest, Hungary.
Microtiter-plate-based systems are unified platforms of high-throughput experimentation (HTE). These polymeric devices are used worldwide on a daily basis-mainly in the pharmaceutical industry-for parallel syntheses, reaction optimization, various preclinical studies and high-throughput screening methods. Accordingly, laboratory automation today aims to handle these commercially available multiwell plates, making developments focused on their modifications a priority area of modern applied research.
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