Abstract: The present invention belongs to the field of medicinal chemistry and relates to a class of substituted tricyclic compounds as PRMT5 inhibitors and the use thereof. Specifically, the present invention provides a compound represented by formula (A) or an isomer, pharmaceutically acceptable salt, solvate, crystal or prodrug thereof, a preparation method therefor, a pharmaceutical composition containing the compounds, and the use of the compounds or the composition for treating a disease mediated by PRMT5. The compounds of the present invention show significant inhibitory activity on PRMT5.

Abstract: The present disclosure provides a loading apparatus and a physical vapor deposition (PVD) apparatus. The loading apparatus includes a pedestal configured to support a workpiece; and a first support member placed on the pedestal and configured to push up a cover ring when the pedestal is at an operation position to prevent an overlapping portion of a cover ring and the workpiece from contacting each other. In the loading apparatus and the PVD apparatus, the first support member supports the cover ring, such that the cover ring does not contact the workpiece, thereby reducing stress forces on the workpiece by external components.

Abstract: The present disclosure provides a loading apparatus and a physical vapor deposition (PVD) apparatus. The loading apparatus includes a pedestal configured to support a workpiece; and a first support member placed on the pedestal and configured to push up a cover ring when the pedestal is at an operation position to prevent an overlapping portion of a cover ring and the workpiece from contacting each other. In the loading apparatus and the PVD apparatus, the first support member supports the cover ring, such that the cover ring does not contact the workpiece, thereby reducing stress forces on the workpiece by external components.