Comprehensive understanding of glioblastoma molecular phenotypes:classification,characteristics,and transition

Among central nervous system-associated malignancies,glioblastoma(GBM)is the most common and has the highest mortality rate.The high heterogeneity of GBM cell types and the complex tumor microenvironment frequently lead to tumor recurrence and sudden relapse in patients treated with temozolomide.In precision medicine,research on GBM treatment is increasingly focusing on molecular subtyping to precisely characterize the cellular and molecular heterogeneity,as well as the refractory nature of GBM toward therapy.Deep understanding of the different molecular expression patterns of GBM subtypes is critical.Researchers have recently proposed tetra fractional or tripartite methods for detecting GBM molecular subtypes.The various molecular subtypes of GBM show significant differences in gene expression patterns and biological behaviors.These subtypes also exhibit high plasticity in their regulatory pathways,oncogene expression,tumor microenvironment alterations,and differential responses to standard therapy.Herein,we summarize the current molecular typing scheme of GBM and the major molecular/genetic characteristics of each subtype.Furthermore,we review the mesenchymal transition mechanisms of GBM under various regulators.

Double BP Q-Learning Algorithm for Local Path Planning of Mobile Robot

Aiming at the dimension disaster problem, poor model generalization ability and deadlock problem in special obstacles environment caused by the increase of state information in the local path planning process of mobile robot, this paper proposed a Double BP Q-learning algorithm based on the fusion of Double Q-learning algorithm and BP neural network. In order to solve the dimensional disaster problem, two BP neural network fitting value functions with the same network structure were used to replace the two Q value tables in Double Q-Learning algorithm to solve the problem that the Q value table cannot store excessive state information. By adding the mechanism of priority experience replay and using the parameter transfer to initialize the model parameters in different environments, it could accelerate the convergence rate of the algorithm, improve the learning efficiency and the generalization ability of the model. By designing specific action selection strategy in special environment, the deadlock state could be avoided and the mobile robot could reach the target point. Finally, the designed Double BP Q-learning algorithm was simulated and verified, and the probability of mobile robot reaching the target point in the parameter update process was compared with the Double Q-learning algorithm under the same condition of the planned path length. The results showed that the model trained by the improved Double BP Q-learning algorithm had a higher success rate in finding the optimal or sub-optimal path in the dense discrete environment, besides, it had stronger model generalization ability, fewer redundant sections, and could reach the target point without entering the deadlock zone in the special obstacles environment.

An enhanced spectral diversity coregistration method for dualpolarimetric Sentinel-1A/B TOPS data

Sentinel-1A/B data are crucial for retrieving numerical information about surface phenomena and processes.Coregistration of terrain observation by progressive scans(TOPS)data is a critical step in its application.TOPS data must be fundamentally co-registered with an accuracy of 0.001 pixels.However,various decorrelation factors due to natural vegetation and seasonal effects affect the coregistration accuracy of TOPS data.This paper proposed an enhanced spectral diversity coregistration method for dual-polarimetric(PolESD)Sentinel-1A/B TOPS data.The PolESD method suppresses speckle noise based on a unified non-local framework in dual-pol Synthetic Aperture Radar(SAR),and extracts the phase of the optimal polarization channel from the denoised polarimetric interferometric coherency matrix.Compared with the traditional ESD method developed for single-polarization data,the PolESD method can obtain more accurate coherence and phase and get more pixels for azimuth-offset estimation.In bare areas covered with low vegetation,the number of pixels selected by PolESD is more than the Boxcar method.It can also correct misregistration more effectively and eliminate phase jumps in the burst edge.Therefore,PolESD will help improve the application of TOPS data in low-coherence scenarios.

有机高分子结晶的表界面效应:从正烷烃到高分子

表界面处的物质具有不同于本体的物理性质,表界面物理化学一直是化学和材料科学领域的重要内容.近年来,有机高分子表界面相关的结晶新现象不断涌现,引起了广泛关注.结合本课题组的工作,本文总结了近年来表界面处有机高分子结晶的新结果,探讨了不同体系中丰富的实验现象背后的物理机制.首先介绍了表界面相关的重要概念,包括表(界)面张力、均相和异相成核;其次,以代表性实例梳理了有机高分子表界面的结晶特性,主要包括长链烷烃表面结晶、高分子的预结晶、表面引起的亚稳态增强以及界面吸附对结晶的影响等;再次,探讨了不同结晶现象之间的关联性;最后,对目前表界面结晶领域尚未解决的问题进行了讨论.

Electron-ion collider in China

Lepton scattering is an established ideal tool for studying inner structure of small particles such as nucleons as well as nuclei.As a future high energy nuclear physics project,an Electron-ion collider in China(EicC)has been proposed.It will be constructed based on an upgraded heavy-ion accelerator,High Intensity heavy-ion Accelerator Facility(HIAF)which is currently under construction,together with a new electron ring.The proposed collider will provide highly polarized electrons(with a po-larization of 80%)and protons(with a polarization of 70%)with variable center of mass energies from 15 to 20 GeV and the luminosity of(2–3)×1033 cm^(−2)·s^(−1).Polarized deuterons and Helium-3,as well as unpolarized ion beams from Carbon to Uranium,will be also available at the EicC.The main foci of the EicC will be precision measurements of the structure of the nucleon in the sea quark region,including 3D tomography of nucleon;the partonic structure of nuclei and the parton interaction with the nuclear environment;the exotic states,especially those with heavy flavor quark contents.In addition,issues fundamental to understanding the origin of mass could be addressed by measurements of heavy quarkonia near-threshold production at the EicC.In order to achieve the above-mentioned physics goals,a hermetical detector system will be constructed with cutting-edge technologies.This document is the result of collective contributions and valuable inputs from experts across the globe.The EicC physics program complements the ongoing scientific programs at the Jefferson Laboratory and the future EIC project in the United States.The success of this project will also advance both nuclear and particle physics as well as accelerator and detector technology in China.

A sustained release of BMP2 in urine-derived stemcells enhances the osteogenic differentiation and the potential of bone regeneration

Cell-based tissue engineering is one of the optimistic approaches to replace current treatments for bone defects.Urine-derived stem cells(USCs)are obtained non-invasively and become one of the promising seed cells for bone regeneration.An injectable BMP2-releasing chitosan microspheres/type I collagen hydrogel(BMP2-CSM/Col I hydrogel)was fabricated.USCs proliferated in a time-dependent fashion,spread with good extension and interconnected with each other in different hydrogels both for 2D and 3D models.BMP2 was released in a sustained mode for more than 28 days.Sustained-released BMP2 increased the ALP activities and mineral depositions of USCs in 2D culture,and enhanced the expression of osteogenic genes and proteins in 3D culture.In vivo,the mixture of USCs and BMP2-CSM/Col I hydrogels effectively enhanced bone regeneration,and the ratio of new bone volume to total bone volume was 38%after 8weeks of implantation.Our results suggested that BMP2-CSM/Col I hydrogels promoted osteogenic differentiation of USCs in 2D and 3D culture in vitro and USCs provided a promising cell source for bone tissue engineering in vivo.As such,USCs-seeded hydrogel scaffolds are regarded as an alternative approach in the repair of bone defects.

Removal of perchlorate from aqueous solution by cross-linked Fe(Ⅲ)-chitosan complex

Cross-linked Fe（III）-chitosan composite （Fe-CB） was used as the adsorbent for removing perchlorate from the aqueous solution. The adsorption experiments were carried out by varying contact time, initial concentrations, temperatures, pH, and the presence of co-existing anions. The morphology of the adsorbent was discussed using FT-IR and SEM with X-EDS analysis. The pH ranging from 3.0-10.2 exhibited very little effect on the adsorption capability. The perchlorate uptake onto Fe-CB obeyed Langmuir isotherm model. The adsorption process was rapid and the kinetics data obeyed the pseudo second-order model well. The eluent of 2.5% （W/V） NaC1 could regenerate the exhausted adsorbent efficiently. The adsorption mechanism was also discussed.

“Nanocompoundsite”:Nano phased polymer dispersed in inorganic matrix via covalent bonds

Herein we demonstrate a new strategy to construct inorganic–organic“nanocompoundsite”,i.e.,a material that nano phased polymer is dispersed in consecutive inorganic matrix via covalent bonds,which is different from the conventional nanocomposite with polymer as matrix and inorganic nanomaterials as dispersed phase.As a representative system,SiOx/polydimethylsiloxane(PDMS)nanocompoundsite was prepared from a polymeric precursor of perhydropolysilazane(PHPS)modified by carbohydroxyl end-capped PDMS(HOC-PDMS),through a room-temperature vacuum ultraviolet(VUV)irradiation manner.By adjusting HOC-PDMS/PHPS ratio below 20%,PDMS fully binds to the PHPS derived SiOx matrix via Si-O-C bond to form the inorganic-organic SiOx/PDMS nanocompoundsite(ISPN)without noticeable phase separation.The introduction of PDMS into ISPN renders its initial decomposition temperature increase over 110℃.The remarkable enhancement of thermal stability for PDMS is due to the restriction of terminal hydroxyl induced back-biting reaction and main chain degradation by the inorganic matrix and the covalent binding between PDMS and SiOx.This novel strategy can further extend to hydroxyl terminated PDMS,polyethylene glycol,and acrylic resin,with the initial decomposition temperature of each polymer increasing by over 110,150 and 100℃,respectively.More importantly,the nanocompoundsite combines the characteristics of inorganic matrix and polymer.The coating based on SiOx/PDMS nanocompoundsite exhibits good flexibility,outstanding interfacial binding strength,ultra-high hardness as well as excellent hydrophobicity.