Collaborative Pushing and Grasping of Tightly Stacked Objects via Deep Reinforcement Learning

Directly grasping the tightly stacked objects may cause collisions and result in failures,degenerating the functionality of robotic arms.Inspired by the observation that first pushing objects to a state of mutual separation and then grasping them individually can effectively increase the success rate,we devise a novel deep Q-learning framework to achieve collaborative pushing and grasping.Specifically,an efficient non-maximum suppression policy(PolicyNMS)is proposed to dynamically evaluate pushing and grasping actions by enforcing a suppression constraint on unreasonable actions.Moreover,a novel data-driven pushing reward network called PR-Net is designed to effectively assess the degree of separation or aggregation between objects.To benchmark the proposed method,we establish a dataset containing common household items dataset(CHID)in both simulation and real scenarios.Although trained using simulation data only,experiment results validate that our method generalizes well to real scenarios and achieves a 97%grasp success rate at a fast speed for object separation in the real-world environment.

PROTACs:great opportunities for academia and industry (an update from 2020 to 2021)

PROteolysis TArgeting Chimeras(PROTACs)technology is a new protein-degradation strategy that has emerged in recent years.It uses bifunctional small molecules to induce the ubiquitination and degradation of target proteins through the ubiquitin–proteasome system.PROTACs can not only be used as potential clinical treatments for diseases such as cancer,immune disorders,viral infections,and neurodegenerative diseases,but also provide unique chemical knockdown tools for biological research in a catalytic,reversible,and rapid manner.In 2019,our group published a review article“PROTACs:great opportunities for academia and industry”in the journal,summarizing the representative compounds of PROTACs reported before the end of 2019.In the past 2 years,the entire field of protein degradation has experienced rapid development,including not only a large increase in the number of research papers on protein-degradation technology but also a rapid increase in the number of small-molecule degraders that have entered the clinical and will enter the clinical stage.In addition to PROTAC and molecular glue technology,other new degradation technologies are also developing rapidly.In this article,we mainly summarize and review the representative PROTACs of related targets published in 2020–2021 to present to researchers the exciting developments in the field of protein degradation.The problems that need to be solved in this field will also be briefly introduced.

Developing selective PI3K degraders to modulate both kinase and non-kinase functions

For the first time,proteolysis-targeting chimeras(PROTAC)technology was utilized to achieve the isoform-selective degradation of class I phosphoinositide 3-kinases(PI3Ks)in this study.Through screening and optimization,the PROTAC molecule ZM-PI05 was identified as a selective degrader of p110αin multiple breast cancer cells.More importantly,the degrader can down-regulate p85 regulatory subunit simultaneously,thereby inhibiting the non-enzymatic functions of PI3K that are independent on p110catalytic subunits.Therefore,compared with PI3K inhibitor copanlisib,ZM-PI05 displayed the stronger anti-proliferative activity on breast cancer cells.In brief,a selective and efficient PROTAC molecule was developed to induce the degradation of p110αand concurrent reduction of p85 proteins,providing a tool compound for the biological study of PI3K-αby blocking its enzymatic and non-enzymatic functions.