The growing demand for high-quality transportation fuels requires their cost-effective production by hydrodesulfurization of crude oils using heterogeneous catalysts. To study the three-dimensional (3D) structure of such a commercial, sulfided Ni-Mo/gamma-Al2O3 catalyst, electron tomography was applied. The MoS2 particles form an interconnected complex structure within the mesopores of the alumina support. Spatial organization, morphology, and orientation of the MoS2 particles in the pores were resolved with sufficient accuracy to display the 6-A-spaced MoS2 crystal planes. The proximity of the MoS2 edge planes and more loosely interacting MoS2 basal planes to the alumina support showed the presence of pores smaller than 3 nm, which was confirmed by physisorption experiments. The actual shape of the MoS2 particles cannot be described by simple models as derived from studies on model catalysts. Electron tomography is a unique tool to study the actual 3D structure of complex industrial catalysts with sub-nanometer resolution.
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As more powerful high performance computing resources are becoming available, there is a new opportunity to bring the unique capabilities of molecular dynamics (MD) simulations to cell-scale systems. Membranes are ubiquitous within cells and are responsible for a diverse set of essential biological functions, but building atomistic models of cell-scale membranes for MD simulations is immensely challenging because of their vast sizes, complex geometries, and complex compositions. To meet this challenge, we have developed xMAS Builder (E perimentally-Derived embranes of rbitrary hape Builder), which is designed to take experimental lipidomics and structural (e.
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December 2024
Pulmonology, Algemeen Ziekenhuis Glorieux, Ronse, BEL.
Heterotaxy syndrome is characterized by abnormal left-right arrangement of thoracoabdominal organs and is frequently associated with complex cardiac anomalies. However, cases with predominant extracardiac manifestations are increasingly recognized. This report describes a 20-year-old female of North African descent with consanguineous parentage, who presented with chronic cough and exertional dyspnea persisting over several years.
View Article and Find Full Text PDFSmall
January 2025
State Key Laboratory of Green Chemical Engineering and Industrial Catalysis, School of Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China.
Zeolitic nanosheets possess great potential in catalysis due to their enhanced transport property and accessibility toward bulky molecules compared to conventional micron- meter scale crystals. However, the generation of Beta zeolite nanosheets, which are crucial for industrial catalysis, is still challenging for its intergrowth nature. In this work, aluminosilicate Beta nanosheets of ca.
View Article and Find Full Text PDFMed Phys
January 2025
Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, Hokkaido, Japan.
Background: The use of iodinated contrast-enhancing agents in computed tomography (CT) improves the visualization of relevant structures for radiotherapy treatment planning (RTP). However, it can lead to dose calculation errors by incorrectly converting a CT number to electron density.
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Exp Eye Res
January 2025
Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, China. Electronic address:
The study aimed to compare the effects of different types of excimer laser keratectomy on rabbit corneas and to identify the optimal disease model for corneal ectasia. Additionally, investigating the structural and molecular alterations in the novel disease model helped explore the mechanisms underlying biomechanical cues in corneal ectasia. 2.
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