摘要：In gamma camera and single-photon emission computerized tomography, the collimator removes most photons. Here, a gamma camera without collimator utilizes a specific arrangement of detectors. Instead of bending beams(like a lens) or directing beams(by parallel hole collimator), changes are created in detectors' field of view(FOV), so that each detector's FOV looks different from others. Simulation proved this theory, with 98 detectors(2 cm 9 1.41 cm) arranged in a zigzag manner for Monte Carlo simulation. A radioactive source with energy of140 ke V was situated on the detectors' faces. Sixty projections, each 3(0 –179) apart, were simulated by Monte Carlo N-Particle(MCNP) 4C code, rotating detectors around a radioactive point. The band containing the radioactive source is clearly visible in each *** obtained after simulation in different projections were reconstructed, and point source location emerged correctly. Simulation of gamma camera with zigzag arrangement of detectors and MCNP-4C code demonstrated that one could string the space and determine radioactive source by image reconstruction without using collimators, solely through these special detectors' distribution.

摘要：Radial imaging techniques, such as projection-reconstruction （PR）, are used in magnetic resonance imaging （MRI） for dynamic imaging, angiography, and short-T2 imaging. They are less sensitive to flow and motion artifacts, and support fast imaging with short echo times. However, aliasing and streaking artifacts are two main sources which degrade radial imaging quality. For a given fixed number of k-space projections, data distributions along radial and angular directions will influence the level of aliasing and streaking artifacts. Conventional radial k-space sampling trajectory introduces an aliasing artifact at the first principal ring of point spread function （PSF）. In this paper, a shaking projection （SP） k-space sampling trajectory was proposed to reduce aliasing artifacts in MR images. SP sampling trajectory shifts the projection alternately along the k-space center, which separates k-space data in the azimuthal direction. Simulations based on conventional and SP sampling trajectories were compared with the same number projections. A significant reduction of aliasing artifacts was observed using the SP sampling trajectory. These two trajectories were also compared with different sampling frequencies. ASP trajectory has the same aliasing character when using half sampling frequency （or half data） for reconstruction. SNR comparisons with different white noise levels show that these two trajectories have the same SNR character. In conclusion, the SP trajectory can reduce the aliasing artifact without decreasing SNR and also provide a way for undersampling recon- struction. Furthermore, this method can be applied to three-dimensional （3D） hybrid or spherical radial k-space sampling for a more efficient reduction of aliasing artifacts.

摘要：The efficient and safe operation of large fusion devices strongly relies on the plasma configuration inside the vacuum *** is important to construct the proper plasma equilibrium with a desired plasma *** order to construct the target configuration,a shape constraint module has been developed in the tokamak simulation code（TSC）,which controls the poloidal flux and the magnetic field at several defined control *** is used to construct the double null,lower single null,and quasi-snowflake configurations for the required target shape and calculate the required PF coils *** flexibility and practicability of this method have been verified by the simulated results.

摘要：KTX（Keda Torus for eXperiment）is a new reversed field pinch *** KTX plasma control system（PCS）can provide real-time,stable,flexible plasma control which is designed by ASIPP（Institute of Plasma physics,Chinese Academy of Sciences）,based on the Linux cluster system and EPICS（Experimental physics and Industrial Control System）framework,and developed from DIII-D（Doublet III-D）*** control of the equilibrium field in KTX uses a PID（Proportional-Integral-Derivative）feedback *** control of the gas injection is an open loop *** plasma control simulation system is one part of the plasma control system,which is used to test the plasma control algorithm if it is revised and *** KTX PCS has been successfully tested using HT-7（Hefei Torus 7）experiment data in simulation *** the next phase,an error field feedback control and KTX simulator will be added to the KTX PCS,and the KTX PCS will be applied in experiments in the future.

摘要：Constructing graphene-based heterostructures with large interfacial area is an efficient approach to enhance the electrochemical performance of supercapacitors but remains great challenges in their ***,a novel ultra-small amorphous Fe_(2)O_(3)nanodots/graphene heterostructure(a-Fe_(2)O_(3)NDs/RGO)aerogel was facilely synthesized via excessive metal-ion-induced self-assembly and subsequent calcination route using Prussian blue/graphene oxide(PB/GO)composite aerogel as *** deliberately designed a-Fe_(2)O_(3)NDs/RGO heterostructure offers a highly interconnected porous conductive network,large heterostructure interfacial area,and plenty of accessible active sites,greatly facilitating the electron transfer,electrolyte diffusion,and pseudocapacitive *** obtained a-Fe_(2)O_(3)NDs/RGO aerogel could be used as flexible free-standing electrodes after mechanical compression,which exhibited a significantly enhanced specific capacitance of 347.4 F·g^(-1)at 1 A·g^(-1),extraordinary rate capability of 184 F·g^(-1)at 10 A·g^(-1),and decent cycling *** the as-prepared a-Fe_(2)O_(3)NDs/RGO as negative electrodes and the Co_(3)O_(4)NDs/RGO as positive electrodes,an all-solid-state asymmetric supercapacitor(a-Fe_(2)O_(3)NDs/RGO//Co_(3)O_(4)NDs/RGO asymmetric supercapacitor(ASC))was assembled,which delivered a high specific capacitance of 69.1 F·g^(-1)at 1 A·g^(-1)and an impressive energy density of 21.6 W·h·k·g^(-1)at 750 W·k·g^(-1),as well as good cycling stability with a capacity retention of 94.3%after 5,000 *** work provides a promising avenue to design high-performance graphene-based composite electrodes and profound inspiration for developing advanced flexible energy-storage devices.

摘要：The lifespan of biological heart valve prostheses available in the market is limited due to structural alterations caused by calcium phosphate deposits formed from blood plasma in contact with the *** objective of this work is to present a comparative methodology for the investigation of the formation of calcium phosphate deposits on bioprosthetic and tissue-engineered scaffolds in vitro and the influence of mechanical forces on tissue *** on earlier investigations on biological mineralization at constant supersaturation,a circulatory loop simulating dynamic blood flow and physiological pressure conditions was *** system was appropriately adapted to evaluate the calcification potential of decellularized(DCV)and glutaraldehyde-fixed(GAV)porcine aortic *** indicated that DCV calcified at higher,statistically nonsignificant,rates in comparison with *** difference was attributed to the tissue surface modifications and cell debris leftovers from the decellularization *** analysis of the solids deposited after 20 h by scanning electron microscopy in combination with chemical microanalysis electron-dispersive spectroscopy identified the solid formed as octacalcium phosphate(Ca8(PO4)6H2·5H2O,OCP).OCP crystallites were preferentially deposited in high mechanical stress areas of the test ***,GAV tissues developed a significant transvalvular pressure gradient increase past 36 h with a calcium deposition distribution similar to the one found in explanted *** conclusion,the presented in vitro circulatory model serves as a valuable prescreening methodology for the investigation of the calcification process of bioprosthetic and tissue-engineered valves under physiological mechanical load.

摘要：The protein-based molecular recognition of the adenine ring is essential to understand protein function and drug design as *** this paper,a variety of the adenine-based inhibitors with modified groups of amino groups,nitrogen and oxygen atoms in the aromatic ring are designed,and the binding capability of these adenosine analogues with an aminoglycoside antibiotic kinase [APH(3')-IIIa] are investigated with activity assays and isothermal titration calorimetry(ITC) experiments.1-aminoisoquinoline is one of the weakest substrates bound to APH(3')-IIIa with the lowest affinity(high ki and high kd) and the smallest negative value of free energy change(G) among the inhibitors *** binding process of adenine and 5-nitroisoquinoline to APH(3')-IIIa is an enthalpy-driven event with unfavorable entropy,which is consistent with the energy change induced by the binding of ATP to the ***,the reverse is true for 1-aminoisoquinoline,3-amino-5-nitrobenzisothiazole,5-aminoisoquinoline binding to the enzyme because the entropy is more favorable and the enthalpy makes a lower contribution to the binding *** results suggest that small changes of the adenine ring can lead to significant influence on the ability of these analogues to occupy the adenine-binding region of the enzyme,which can be the potential inhibitors as drug candidates against the bacterial resistance.

摘要：Biophysical restrictions regulate protein diffusion,nucleus deformation,and cell migration,which are all universal and important processes for cells to perform their biological ***,current technologies addressing these multiscale questions are extremely ***,through two-photon polymerization(TPP),we present the precise,low-cost,and multiscale microstructures(micro-fences)as a versatile investigating *** nanometer-scale printing resolution and multiscale scanning capacity,TPP is capable of generating micro-fences with sizes of 0.5-1000μ*** micro-fences are utilized as biophysical restrictions to determine the fluidity of supported lipid bilayers(SLB),to investigate the restricted diffusion of Src family kinase protein Lck on SLB,and also to reveal the mechanical bending of cell nucleus and T cell climbing *** together,the proposed versatile and low-cost micro-fences have great potential in probing the restricted dynamics of molecules,organelles,and cells to understand the basics of physical biology.

摘要：In this paper,we present a 3D printed tumor spheroidal model suitable for drug *** model is based on a hydroxyethyl cellulose/alginate/gelatin(HCSG)composite biomaterial that has three distinct properties:(1)the HCSG is similar to the commercial basement membrane extract in Ki67,MUC1,and PARP1 expressions of MCF-7 cells for embedding culture;(2)the HCSG is printable at room temperature;and(3)the HCSG can be large-scale manufactured at an ultralow *** printed a 3D MCF-7 spheroid model with HCSG and characterized it in terms of cell viability,spheroid size,key protein expression,and mitochondrial metabolic *** used the 3D MCF-7 spheroid model to evaluate the anti-breast cancer activity of 13 amino acid-based flavone phosphoramidates and found that the alanine structure induced a stronger drug resistance,whereas phenylalanine hardly caused drug resistance in the MCF-7 *** is the first time that 3D bioprinting technology has been used in a structure–activity relationship study.

摘要：Limitations of monolayer culture conditions have motivated scientists to explore new models that can recapitulate the architecture and function of human organs more *** advances in the improvement of protocols have resulted in establishing three-dimensional(3D)organ-like architectures called‘organoids’that can display the characteristics of their corresponding real organs,including morphological features,functional activities,and personalized responses to specific *** discuss different organoid-based 3D models herein,which are classified based on their original germinal *** of organoids simulating the complexity of real tissues could provide novel platforms and opportunities for generating practical knowledge along with preclinical studies,including drug screening,toxicology,and molecular pathophysiology of *** paper also outlines the key challenges,advantages,and prospects of current organoid systems.