Abstract: A bidirectional Littrow two-degree-of-freedom grating interference measurement device based on double gratings includes a transmission two-dimensional grating and a reflection two-dimensional grating. A dual-frequency laser emitted by a light source passes through the transmission two-dimensional grating with a specific grating pitch to form four beams in X direction and Y direction, the four beams are incident on the reflection two-dimensional grating at a Littrow angle, and the four beams diffracted by the reflection two-dimensional grating return to the transmission two-dimensional grating in an incidence direction along the same path; different orders of transmission light of the four beams of light in different directions may form stable interference signals carrying displacement information, and the stable interference signals are received by a detector.

Abstract: Disclosed are a grating displacement measurement device and a grating displacement measurement method using a double-layer floating reading head, a medium, and an apparatus. A first measurement grating group is arranged on two first side edges of a substrate working surface, and a second measurement grating group is symmetrically arranged on both sides of a first reference line and close to a light-through member. A reading component is provided between a first measurement grating and a second measurement grating arranged on the same side, and each reading component is used to collect a first position information of the first measurement grating and a second position information of the second measurement grating. In the technical solutions, by using multi-channel position information output by two reading components in combination with a displacement solution algorithm.

Abstract: Provided herein are gene repressor systems comprising fusion proteins, such as fusion proteins comprising a DNA binding domain such as a TALE, zinc finger or catalytically-dead CRISPR protein and guide nucleic acid (gRNA), which are useful in the repression of a proprotein convertase subtilisin/kexin Type 9 (PCSK9) gene. Also provided are methods of using such systems to repress transcription of PCSK9.

Abstract: Provided herein are gene repressor systems comprising fusion proteins, such as fusion proteins comprising a DNA binding domain such as a TALE, zinc finger or catalytically-dead CRISPR protein and guide nucleic acid (gRNA), which are useful in the repression of a proprotein convertase subtilisin kexin Type 9 (PCSK9) gene. Also provided are methods of using such systems to repress transcription of PCSK9.

Abstract: This disclosure provides systems, methods, and compositions for site specific genetic engineering comprising the use of CRISPR effectors and trans-splicing. The disclosure also relates to methods of using the systems and compositions for treating diseases as well as diagnostics.

Abstract: This disclosure provides systems, methods, and compositions for RNA-guided RNA-targeting CRISPR effectors for the treatment of diseases, and for use as diagnostics. In addition, nucleotide deaminase functionalized CRISPR systems for RNA editing RNA knockdown, viral resistance, splicing modulation, RNA tracking, translation modulation, and epi-transcriptomic modifications are disclosed.