Abstract: The present invention provides a bacterial continuous evolution system, an orthogonal error-prone DNA polymerase, and a continuous evolution method. In the present invention, by combining an orthogonal DNA replication system and an orthogonal error-prone DNA polymerase, a continuous evolution method that includes all mutant types, enables long-DNA-fragment mutation, and is good in continuity and simple and convenient to operate is obtained. By inducing the opening and closing of DNA polymerase expression, switching between a linear plasmid error-prone mutation process and a high-fidelity replication process is realized, so as to achieve the efficient and continuous evolution of a target DNA sequence.

Abstract: The invention provides a Saccharomyces cerevisiae strain for producing a human milk lipid substitute. By integrating a heterologous lysophosphatidic acid acyltransferase into Saccharomyces cerevisiae and knocking out its own natural lysophosphatidic acid acyltransferase, the content of palmitic acid (C16:0) at Sn-2 position of triacylglycerol produced by Saccharomyces cerevisiae is increased, to synthesize a human milk lipid substitute. On this basis, a metabolic pathway related gene is knocked out, to further increase the content of human milk lipid substitute in the product. In the present invention, a human milk lipid substitute is de novo synthesized by Saccharomyces cerevisiae for the first time, in which the total fatty acid is 15% or more, and the relative content of C16:0 at Sn-2 position reaches about 60%.

Abstract: The present disclosure relates to systems and methods for imaging. The method may include obtaining a first image and topology data of an object, wherein the topology data may include first topology data and second topology data, and the first topology data may correspond to the second topology data. The method may also include determining a base material density image corresponding to the first image, determining a difference in the topology data based on the first topology data and the second topology data, and determining a second image corresponding to the first image based on the first image, the base material density image, and the difference in the topology data.

Abstract: An anti-scatter grid, a detector with such an anti-scatter grid and a radiation imaging system including such a detector with an anti-scatter grid are provided. The anti-scatter grid includes at least one grid wall. The parameters of the grid wall may be adjusted to arrive a uniform scatter-to-primary ratio. The parameters of the grid wall comprise thickness, height, shape, or position of the grid wall, or width of interspace between two grid walls. The detector includes the anti-scatter grid, at least one photosensor, and at least one scintillator. The radiation system includes a radiation generator, a radiation detector with the anti-scatter grid, and a processor.

Abstract: The present disclosure discloses a method for positioning. The method may include obtaining a scout image of a target object and inputting the scout image of the target object into a positioning model. The method may also include determining a positioning frame in the scout image based on an output result of the positioning model. The positioning model may be obtained by training based on training scout images and information of the gold standard positioning frames. Each of the gold standard positioning frames may be in, from, or determined based on one of the training scout images and used for scanning.

Abstract: The present disclosure relates to a method and system for adjusting a focal point position of an X-ray tube. The method may include: obtaining a first thermal capacity and a first position of a focal point of an X-ray tube; obtaining a second thermal capacity of the X-ray tube; determining a second position of the focal point the X-ray tube based on the second thermal capacity; determining a target grid voltage difference of a focusing cup of the X-ray tube based on the first position and the second position of the focal point; and adjusting the X-ray tube based on the target grid voltage difference.

Abstract: The present disclosure provides a medical device. The medical device may include a gantry, a table, and one or more disinfection devices. The gantry may include a bore configured to accommodate an object for scan. The table may be configured to support the object and move the object into the bore. The one or more disinfection devices may be configured for disinfection.

Abstract: An anti-scatter grid, a detector with such an anti-scatter grid and a radiation imaging system including such a detector with an anti-scatter grid are provided. The anti-scatter grid includes at least one grid wall. The parameters of the grid wall may be adjusted to arrive a uniform scatter-to-primary ratio. The parameters of the grid wall comprise thickness, height, shape, or position of the grid wall, or width of interspace between two grid walls. The detector includes the anti-scatter grid, at least one photosensor, and at least one scintillator. The radiation system includes a radiation generator, a radiation detector with the anti-scatter grid, and a processor.

Abstract: The present disclosure relates to a method and a system for computed tomography imaging. The method may comprise obtaining original data; obtaining a preprocessing result by preprocessing the original data; obtaining intensity of the artifact based on the preprocessing result; and updating a damaged channel or the air correction table based on the intensity of the artifact. Updating the air correction table may comprise: obtaining a first air correction table corresponding to a first temperature of detector; obtaining real-time temperature of detector; and obtaining a second air correction table corresponding to the real-time temperature based on the real-time temperature and the first air correction table.

Abstract: An anti-scatter grid, a detector with such an anti-scatter grid and a radiation imaging system including such a detector with an anti-scatter grid are provided. The anti-scatter grid includes at least one grid wall. The parameters of the grid wall may be adjusted to arrive a uniform scatter-to-primary ratio. The parameters of the grid wall comprise thickness, height, shape, or position of the grid wall, or width of interspace between two grid walls. The detector includes the anti-scatter grid, at least one photosensor, and at least one scintillator. The radiation system includes a radiation generator, a radiation detector with the anti-scatter grid, and a processor.

Abstract: A radiation emission device is provided. The radiation emission device may include an anode, a first cathode, a heating device and an enclosure. The first cathode may include a first filament that emit an electron beam striking the anode to generate radioactive rays for imaging. The heating device may be located outside of the first cathode and be configured to warm up the anode. The enclosure may be configured to enclosure the first cathode and the anode.

Abstract: The present disclosure relates to a method and a system for computed tomography imaging. The method may comprise obtaining original data; obtaining a preprocessing result by preprocessing the original data; obtaining intensity of the artifact based on the preprocessing result; and updating a damaged channel or the air correction table based on the intensity of the artifact. Updating the air correction table may comprise: obtaining a first air correction table corresponding to a first temperature of detector; obtaining real-time temperature of detector; and obtaining a second air correction table corresponding to the real-time temperature based on the real-time temperature and the first air correction table.

Abstract: The present disclosure relates to a method and system for adjusting a focal point position of an X-ray tube. The method may include: obtaining a first thermal capacity and a first position of a focal point of an X-ray tube; obtaining a second thermal capacity of the X-ray tube; determining a second position of the focal point the X-ray tube based on the second thermal capacity; determining a target grid voltage difference of a focusing cup of the X-ray tube based on the first position and the second position of the focal point; and adjusting the X-ray tube based on the target grid voltage difference.

Abstract: An anti-scatter grid, a detector with such an anti-scatter grid and a radiation imaging system including such a detector with an anti-scatter grid are provided. The anti-scatter grid includes at least one grid wall. The parameters of the grid wall may be adjusted to arrive a uniform scatter-to-primary ratio. The parameters of the grid wall comprise thickness, height, shape, or position of the grid wall, or width of interspace between two grid walls. The detector includes the anti-scatter grid, at least one photosensor, and at least one scintillator. The radiation system includes a radiation generator, a radiation detector with the anti-scatter grid, and a processor.

Abstract: The present disclosure relates to a method and a system for computed tomography imaging. The method may comprise obtaining original data; obtaining a preprocessing result by preprocessing the original data; obtaining intensity of the artifact based on the preprocessing result; and updating a damaged channel or the air correction table based on the intensity of the artifact. Updating the air correction table may comprise: obtaining a first air correction table corresponding to a first temperature of detector; obtaining real-time temperature of detector; and obtaining a second air correction table corresponding to the real-time temperature based on the real-time temperature and the first air correction table.

Abstract: The present disclosure relates to a method and system for adjusting a focal point position of an X-ray tube. The method may include: obtaining a first thermal capacity and a first position of a focal point of an X-ray tube; obtaining a second thermal capacity of the X-ray tube; determining a second position of the focal point the X-ray tube based on the second thermal capacity; determining a target grid voltage difference of a focusing cup of the X-ray tube based on the first position and the second position of the focal point; and adjusting the X-ray tube based on the target grid voltage difference.

Abstract: An anti-scatter grid, a detector with such an anti-scatter grid and a radiation imaging system including such a detector with an anti-scatter grid are provided. The anti-scatter grid includes at least one grid wall. The parameters of the grid wall may be adjusted to arrive a uniform scatter-to-primary ratio. The parameters of the grid wall comprise thickness, height, shape, or position of the grid wall, or width of interspace between two grid walls. The detector includes the anti-scatter grid, at least one photosensor, and at least one scintillator. The radiation system includes a radiation generator, a radiation detector with the anti-scatter grid, and a processor.

Abstract: A radiation emission device is provided. The radiation emission device may include an anode, a first cathode, a heating device and an enclosure. The first cathode may include a first filament that emit an electron beam striking the anode to generate radioactive rays for imaging. The heating device may be located outside of the first cathode and be configured to warm up the anode. The enclosure may be configured to enclosure the first cathode and the anode.

Abstract: The present disclosure relates to a method and system for adjusting a focal point position of an X-ray tube. The method may include: obtaining a first thermal capacity and a first position of a focal point of an X-ray tube; obtaining a second thermal capacity of the X-ray tube; determining a second position of the focal point the X-ray tube based on the second thermal capacity; determining a target grid voltage difference of a focusing cup of the X-ray tube based on the first position and the second position of the focal point; and adjusting the X-ray tube based on the target grid voltage difference.