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How chromatin dynamics is regulated to ensure efficient DNA repair remains to be understood. Here, we report that the ubiquitin-specific protease USP11 acts as a histone deubiquitinase to catalyze H2AK119 and H2BK120 deubiquitination. We showed that USP11 is physically associated with the chromatin remodeling NuRD complex and functionally involved in DNA repair process. We demonstrated that USP11-mediated histone deubiquitination and NuRD-associated histone deacetylation coordinate to allow timely termination of DNA repair and reorganization of the chromatin structure. As such, USP11 is involved in chromatin condensation, genomic stability, and cell survival. Together, these observations indicate that USP11 is a chromatin modifier critically involved in DNA damage response and the maintenance of genomic stability.

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This paper considers the problem of localization and circumnavigation of a group of targets, which are either stationary or moving slowly with unknown speed, by a single agent. An estimator is proposed, initially for the stationary target case, to localize the targets and the center of mass of them as well as a control law that forces the agent to move on a circular trajectory around the center of mass of the targets such that both the estimator and the controller are exponentially stable. Then the case where the targets might experience slow but possibly steady movements is studied. The system inputs include the agent's position and the bearing angles to the targets. The performance of the proposed algorithms is verified through simulations. Copyright been studied when the agent(s) can measure the relative position of the target, that is, its range and bearing. In some applications, however, it is preferred to employ localization and circumnavigation algorithms that require less sensed knowledge about the target so that the proposed algorithm can be used to control a UAV with limited payload capacity (and thus limited sensing capability). There have been some research efforts to study such localization and circumnavigation problems using distance-only measurements [13][14][15], bearing-only measurements [16,17], and received signal strength (RSS) measurement [18]. In the scenarios where the agent has to maintain radio silence for the fear that its position will be detected, it is usually preferred not to use distance measurements. This is because of the fact that distance measurement techniques are usually active methods in which the agent must transmit signals. In contrast, RSS measurement techniques and usually bearing measurement techniques are passive methods. RSS-based localization techniques measure the strength of the received signal and use a log-normal radio propagation model to estimate the distance to the target. The path loss exponent is a key parameter in the log-normal model, which depends on the environment in which the sensor is deployed. The problem with this method is that an accurate knowledge of the path loss exponent is required in order to convert signal strength measurements to range, and it can be difficult to obtain [19].The problem of bearings-only target localization has been studied in the literature using statistical estimators such as extended Kalman filter (EKF) and unscented Kalman filter [20,21]. It is assumed in such estimators that the agent knows the system model as well as the noise model. Although these estimators work well when the agent knows the motion characteristics of the target, they cannot be used when the target can move freely while the agent is not aware of the target motion. Many of the current results in the literature assumed that the target is either stationary or moving with a known constant velocity. We however consider the scenario that the target is allowed to move on any directions and the agent does not know the motion characteristics of the target.In th...

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In this work, a liposome-encapsulated chlorophyll derivative pyropheophorbide acid (PPa) (liposome/PPa) nanoparticles are designed for tri-model imaging guided photodynamic therapy (PDT) of cancer.

Docetaxel (DTX), as a member of taxoid family, has been widely used in the treatment of cancers. The present study prepared pH-sensitive DTX-loaded liposomes (DTX-Lips) by thin-film dispersion method and various physico-chemical and morphological properties were examined. The pH sensitivity of in vitro DTX release and the in vivo pharmacokinetics and tissue distribution using Kunming mice were also investigated. The mean particle size and zeta potential of DTX liposomes were (277±2) nm and (−32.60±0.26) mV, respectively. Additionally, in vitro drug release study showed that the cumulative release rate was 1.3 times more at pH 5.0 than at pH 7.4, suggesting a pH-dependent release ability of DTX-Lips. Pharmacokinetic and pharmaceutical studies in comparison with Duopafei ® showed that the half-time period (t 1/2 ) and area under the curve (AUC) of DTX-Lips in mouse plasma were 1.8 times longer and 2.6 times higher, respectively, and that DTX-Lips selectively accumulated in macrophage-rich organs such as liver and spleen. These results together suggest that the DTX-Lips could be a promising formulation for the clinical administration of DTX.

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