Efficacy and safety of preoperative immunotherapy in patients with mismatch repair-deficient or microsatellite instability-high gastrointestinal malignancies

BACKGROUND Programmed death protein(PD)-1 blockade immunotherapy significantly prolongs survival in patients with metastatic mismatch repair-deficient(dMMR)/microsatellite instability-high(MSI-H)gastrointestinal malignancies such gastric and colorectal cancer.However,the data on preoperative immunotherapy are limited.AIM To evaluate the short-term efficacy and toxicity of preoperative PD-1 blockade immunotherapy.METHODS In this retrospective study,we enrolled 36 patients with dMMR/MSI-H gastrointestinal malignancies.All the patients received PD-1 blockade with or without chemotherapy of CapOx regime preoperatively.PD1 blockade 200 mg was given intravenously over 30 min on day 1 of each 21-d cycle.RESULTS Three patients with locally advanced gastric cancer achieved pathological complete response(pCR).Three patients with locally advanced duodenal carcinoma achieved clinical complete response(cCR),followed by watch and wait.Eight of 16 patients with locally advanced colon cancer achieved pCR.All four patients with liver metastasis from colon cancer reached CR,including three with pCR and one with cCR.pCR was achieved in two of five patients with nonliver metastatic colorectal cancer.CR was achieved in four of five patients with low rectal cancer,including three with cCR and one with pCR.cCR was achieved in seven of 36 cases,among which,six were selected for watch and wait strategy.No cCR was observed in gastric or colon cancer.CONCLUSION Preoperative PD-1 blockade immunotherapy in dMMR/MSI-H gastrointestinal malignancies can achieve a high CR,especially in patients with duodenal or low rectal cancer,and can achieve high organ function protection.

Crystal structure and negative thermal expansion of solid solution Lu_2W_(3-x)Mo_xO_(12)

A new series of solid solutions Lu2W3-xMoxO12 （0.5≤r≤2.5） were successfully synthesized by the solid-state method. Their crystal structure and negative thermal expansion properties were studied using high-temperature X-ray powder diffraction and the Rietveld method. All samples of rare-earth ttmgstates and molybdates are found to crystallize in the same orthorhombic structure with space group Pnca and show the negative thermal expansion phenomena related to transverse vibration of bridging oxygen atoms in the structure. Thermal expansion coefficients （TEC） of Lu2W3_xMoxO12 are determined as -20.0× 10^-6 K^-1 for x=0.5 and -16.1×10^-6 K^-1 for x=2.5 but -18.6× 10^-6 and -16.9× 10^-6K^-1 for unsubstituted Lu2W3012 and Lu2M03012 in the identical temperature range of 200 to 800℃. High-temperature X-ray diffraction （XRD） data and bond length analysis suggest that the difference between W-O and Mo-O bond is responsible for the change of TECs after the element substitution in this series of solid solutions.

Hunting problems of multi-quadrotor systems via bearing-based hybrid protocols with hierarchical network

Bearing-based hunting protocols commonly adopt a leaderless consensus method,which requests an entire state of the target for each agent and ignores the necessity of collision avoidance.We investigate a hunting problem of multi-quadrotor systems with hybrid bearing protocols,where the quadrotor systems are divided into master and slave groups for reducing the onboard loads and collision avoidance.The masters obtain the entire state of the target,whose hybrid protocols are based on the displacement and bearing constraints to maintain formation and to avoid the collision in the hunting process.However,the slaves’protocols merely depend on the part state of the masters to reduce loads of data transmission.We also investigate the feasibility of receiving the bearing state from machine vision.The simulation results are given to illustrate the effectiveness of the proposed hybrid bearing protocols.

Band alignment between NiO_(x) and nonpolar/semipolar GaN planes for selective-area-doped termination structure

Band alignment between NiO_(x) and nonpolar GaN plane and between NiO_(x) and semipolar GaN plane are measured by x-ray photoelectron spectroscopy. They demonstrate that the maximum value of the valence band in the unintentional-doped a-plane, m-plane, and r-plane GaN are comparable to each other, which means that all the substrates are of n-type with similar background carrier concentrations. However, the band offset at the NiO_(x)/GaN interface presents obvious crystalline plane dependency although they are coated with the same NiO_(x) films. By fitting the Ga 3 d spectrum obtained from the NiO_(x)/GaN interface, we find that relatively high Ga–O content at the interface corresponds to a small band offset. On the one hand, the high Ga–O content on the GaN surface will change the growth mode of NiO_(x). On the other hand, the affinity difference between Ga and O forms a dipole which will introduce an extra energy band bending.