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A concise, recyclable, and efficient process is presented for the preparation of ()-ketamine (esketamine, ()-) via classic resolution combined with the recycling of the undesired isomer. With commercially available ketone as the starting material, this procedure features three steps including (1) an unique hydroxylation-ring expansion rearrangement, (2) mild amination via methanesulfonate, and (3) chiral separation using -(+)-tartaric acid. The three simple steps are all performed in mild conditions and ()- tartrate is obtained in 99.5% ee without recrystallization. Subsequently, racemization of the unwanted ()- remained in resolution mother liquor was performed in the presence of a Lewis acid in quantitative yield with >99.0% chemical purity. This original and economical process afforded esketamine in 67.4% (28.9% without racemization) overall yield with two times recycling of the mother liquor without column purification. In addition, this procedure can also be applied to the preparation of ()-norketamine, which is a safer potential antidepressant.
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http://dx.doi.org/10.1021/acs.joc.0c01090 | DOI Listing |
Environ Monit Assess
September 2025
Department of Water Resources Study and Research, Water Research Institute, Tehran, Iran.
Small glaciers situated in high mountainous areas are experiencing notable declines, characterized by unprecedented rates of ice loss in recent years. This study investigates the recent changes in surface elevation and mass loss occurring between 2010 and 2023 within the Alamkouh Glacier over three subperiods, one of the biggest glaciers in Iran and the Middle East. These assessments are derived from a combination of high-resolution LiDAR data in 2010 (with a spatial resolution of 20 cm) and multi-temporal surveys conducted using unmanned aerial vehicles (UAVs) in 2018, 2020, and 2023 (with spatial resolutions varied from 10 to 20 cm).
View Article and Find Full Text PDFJ Synchrotron Radiat
November 2025
State Key Laboratory of Chemical Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China.
This study develops an integrated X-ray absorption spectroscopy (XAS) photoemission electron microscopy (PEEM) platform on beamline BL09U at the Shanghai Synchrotron Radiation Facility (SSRF), enabling nanoscale characterization of complex materials through energy-resolved imaging and local-area XAS. By using the wide range of energy tunability, full access to different polarizations and PEEM's surface sensitivity, we have established a gap-monochromator control system under the EPICS framework to synchronize the elliptically polarized undulator (EPU) gap and monochromator energy dynamically, optimizing photon flux stability for absorption fine structure analysis. Combining X-ray magnetic circular dichroism (XMCD) and X-ray magnetic linear dichroism (XMLD) with PEEM and local-area XAS, this platform achieves concurrent mapping of electronic structures and magnetic domains in ferromagnetic nano-patterns, as demonstrated through our studies of NiFe Permalloy using this system.
View Article and Find Full Text PDFJ Synchrotron Radiat
November 2025
Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA.
Nano-laminography combines the penetrating power of hard X-rays with a tilted rotational geometry to deliver high-resolution, three-dimensional images of laterally extended, flat specimens that are otherwise incompatible with, or difficult to image using, conventional nano-tomography. In this work, we demonstrate a full-field, X-ray nano-laminography system implemented with the transmission X-ray microscope at beamline 32-ID of the upgraded Advanced Photon Source at Argonne National Laboratory, USA. By rotating the sample around an axis inclined by 20° to the incident beam, the technique minimizes the long optical path lengths that would otherwise generate excessive artifacts when planar samples are imaged edge-on.
View Article and Find Full Text PDFJ Pathol
September 2025
The North of England Bone and Soft Tissue Tumour Service, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
Indocyanine green (ICG) is a well-established near-infrared dye which has been used clinically for several decades. Recently, it has been utilised for fluorescence-guided surgery in a range of solid cancer types, including sarcoma, with the aim of reducing the positive margin rate. The increased uptake and retention of ICG within tumours, compared with normal tissue, gives surgeons a visual reference to aid resection when viewed through a near-infrared camera.
View Article and Find Full Text PDFPhys Eng Sci Med
September 2025
Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok, 16424, Indonesia.
This study introduces a novel optimization framework for cranial three-dimensional rotational angiography (3DRA), combining the development of a brain equivalent in-house phantom with Figure of Merit (FOM) a quantitative evaluation method. The technical contribution involves the development of an in-house phantom constructed using iodine-infused epoxy and lycal resins, validated against clinical Hounsfield Units (HU). A customized head phantom was developed to simulate brain tissue and cranial vasculature for 3DRA optimization.
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