Adaptive synchronization of a class of fractional-order complex-valued chaotic neural network with time-delay

This paper is concerned with the adaptive synchronization of fractional-order complex-valued chaotic neural networks(FOCVCNNs)with time-delay.The chaotic behaviors of a class of fractional-order complex-valued neural network are investigated.Meanwhile,based on the complex-valued inequalities of fractional-order derivatives and the stability theory of fractional-order complex-valued systems,a new adaptive controller and new complex-valued update laws are proposed to construct a synchronization control model for fractional-order complex-valued chaotic neural networks.Finally,the numerical simulation results are presented to illustrate the effectiveness of the developed synchronization scheme.

Study on the effect of PET/CT-guided nasopharyngeal carcinoma target delineation on the dose received by endangered organs

Objective:To compare the differences of radiation-induced doses between 18F-FDG-PET/CT and CT/MRI-guided target delineation in nasopharyngeal carcinoma in intensity-modulated radiotherapy.Methods:A total of 31 patients with locally advanced nasopharyngeal carcinoma receiving treatment in our hospital from December 2016 to December 2017 were studied in this research,and 18F-FDG-PET/CT and CT/MRI were used to guide the target delineation to develop an intensity-modulated radiotherapy plan(experimental group and control group).The dose differences between GTV and endangered organs in the two groups were compared.Results:Comparison of primary tumor volume:PET/CT was smaller than CT/MRI,and volumes of T3 and T4 were significantly different(P<0.001).Comparison of the two delineation plans,in terms of PGTV in Dmin,Dmean,and D95,the data of experimental group was smaller than that of the control group;in Dmax,the PGTV of the experimental group was larger than that of the control group with P<0.001 considered as a significant difference.In Dmin and Dmax,doses of experimental groups of the spinal cord were lower than those of the control group,showing a significant difference(P=0.022,0.042);In Dmean,there was no difference between the two groups.In Dmax doses of an experimental group of the brainstem and parotid gland were significantly smaller than the control group(P=0.001,0.047)while there was no difference between Dmin and Dmean.There was no difference between the two groups of Dmin,Dmean,and Dmax in the doses received by chiasm and temporal lobe.Conclusion:PET/CT guided target delineation is applied in the simultaneous dose adjustment of intensity-modulated radiation therapy in patients with advanced nasopharyngeal carcinoma.In primary lesion targets shown by MRI/CT,the tumor tissue of PET/CT concentration zone was given a higher dose with relatively smaller average dose and minimum dose in the overall tumor target area.Statistics also showed that the doses received by the spinal cord,brain stem,and parotid gland were reduced with no effect on the optic chiasm and temporal lobe.In the future,more studies should probe into the long-term effects of dose changes on lesion control and endangered organs.

A highly selective magnetic sensor with functionalized Fe/Fe_3O_4 nanoparticles for detection of Pb^(2+)

A magnetic sensor for detection of Pb^2＋ has been developed based on Fe/Fe3O4 nanoparticles modified by3-（3,4-dihydroxyphenyl）propionic acid（DHCA）. The carboxyl groups of DHCA have a strong affinity to coordination behavior of Pb^2＋ thus inducing the transformation of Fe/Fe3O4 nanoparticles from a dispersed to an aggregated state with a corresponding decrease, then increase in transverse relaxation time（T2） of the surrounding water protons. Upon addition of the different concentrations of Pb^2＋ to an aq. solution of DHCA functionalized Fe/Fe3O4 nanoparticles（DHCA-Fe/Fe3O4 NPs）（[Fe] = 90 mmol/L）, the change of T2 values display a good linear relationship with the concentration of Pb^2＋ from 40 μmol/L to 100 μmol/L and from 130 μmol/L to 200 μmol/L, respectively. Owing to the especially strong interaction between DHCA and Pb^2＋, DHCA-Fe/Fe3O4 NPs exhibited a high selectivity over other metal ions.

PEGylated WS_2 nanosheets for X-ray computed tomography imaging and photothermal therapy

WS2 nanosheets were prepared by the solvent-thermal method in the presence of n-butyl lithium, then the exfoliation under the condition of ultrasound. The formed WS2 nanosheets were conjugated with thiol-modified polyethylene glycol （PEG-SH） to improve the biocompatibility. The nanosheets （WS2- PEG） were able to inhibit the growth of a model HeLa cancer cell line in vitro due to the high photothermal conversion efficiency of ~35% irradiated by an 808 nm laser （1 W/cm^2）. As a proof of concept, WS2-PEG nanosheets with the better X-ray attenuation property than the clinical computed tomography （CT） contrast agent （lohexol） could be performed for CT imaging of the lymph vessel.