Rotating wheel filter design and optimization for a uniform depth dose distribution in heavy ion therapy

Treatment planning of heavy-ion radiotherapy involves predictive calculation of not only the physical dose but also the biological dose in a patient body. The goal in designing beam-modulating devices for heavy ion therapy is to achieve uniform biological effects across the spread-out Bragg peak (SOBP). To achieve this, a mathematical model of Bragg peak movement is presented. The parameters of this model have been resolved with Monte Carlo method. And a rotating wheel filter is designed basing on the velocity of the Bragg peak movement.

网络成瘾者心率变异性频谱特征及人格相关因素的研究

The aim of this research is to explore heart rate variability frequency field characteristics and personality influential factors of internet addicts by experimentation and questionnaire. Two studies were carried out: study 1 was to explore the pathological and mental mechanism of internet addicts by heart rate variability physiological index and EPQ and internet addiction scale. Study 2 was to compare the personality and mental characteristics between internet addicts and Non-addicts. The testees were 30 internet addict schoolboys who were in-patient and 43 schoolboys who accorded with qualification from grade 2 in senior high school and sophomore. It is found that: 1、 Internet addicts have obviously lower HFNU than Non-addicts， but have obviously higher LFNU and LF/HF ratio than Non-addicts. Internet addicts have dysfunction in their sympathetic and parasympathetic system; 2、 Internet addicts and Non-addicts have no significant difference in their EPQ except their lying point, but the nervous characteristics of EPQ of internet addicts have influence on their equipoise of parasympathetic system, that is to say when the score of nervous characteristics of EPQ become higher, equipoise of parasympathetic system become worse and worse. However the EPQ personality characteristics of non-addicts have no influence on their sympathetic and parasympathetic system. 3、 The extent of internet addiction of the internet addicts is independent of their equipoise of parasympathetic system, but non-addicts use internet more time, their equipoise of parasympathetic system become lower, there is the significant difference in the neurophysiology between internet addicts and non-addicts. That is to say internet environment is safe to most adolescent, they can make use of internet environment accurately, but internet addicts, their physiological and psychological level has changed to a certain, need to be treated.； 4、 Serious internet game addicts have the metal characteristics of low social support, low purpose in life and low adventure; 5、 The objective support、support utilization of social support questionnaire and sensation seeking characteristics have prognosticative function for internet addiction degree; 6、 Serious internet game addicts have the metal characteristics of low social support, low lying particularity, they are inclined to self abandonment. Serious internet game addicts of low N characteristic have high sensation seeking characteristic, and at the same E personality foundation, they also seek new stimulus with higher intension. There is a prompt that we should pay attention to internet addicts’ personality so that obtain better curative effect for internet addiction therapy.

吗啡相关情境线索的形成及效应表达的神经基础——海马与基底外侧杏仁核在其中的作用

Drug-associated cue-induced relapse to drug seeking causes most difficulties of therapy for drug addiction. Addicts are exposed to two forms of environmental stimuli during drug-taking: contextual stimuli (e.g. a house in which the drug is consumed) and discrete stimuli (DS, e.g. a crack pipe or a syringe for drug). These stimuli become contextual cues and discrete cues, respectively. The incentive value of contextual cues plays a great role in opiates relapse. Compared with drug self-administration model, conditioned place preference (CPP) reflects the approach behavior for drug cues, not concerned with acquisition of operant behaviors. The present study aimed to investigate the role of basolateral amygdala (BLA) and hippocampus in the effect of opiates-related contextual cues using CPP model. Establishing DS-dependent or contextual cues-dependent CPP, the effect of BLA or hippocampus inactivation prior to training phase on acquisition of contextual cues-opiates association was evaluated. Inactivation prior to test phase was used to evaluate roles of BLA and hippocampus in expression of contextual cues-dependent morphine CPP. The main results were as follows: Inactivation of BLA or dorsal hippocampus selectively impaired acquisition of contextual cue-dependent CPP, but inactivation of ventral hippocampus had no impact on acquisition of either DS-dependent or contextual cue-dependent morphine CPP. Inactivation of BLA selectively inhibited expression of contextual cue-depended CPP. Inactivation of ventral hippocampus inhibited expression of both DS-dependent and contextual cue-dependent morphine CPP. These results suggest that BLA and dorsal hippocampus contribute to contextual cue association with opiates but not DS-opiates association. BLA and ventral hippocampus play important roles in incentive value of contextual cues. The present study provides more information for the neurological substrates underlying contextual cues associated with opiates.

叠前地震数据规则化、重建及噪音压制

I address of reconstruction of spatial irregular sampling seismic data to regular grids. Spatial irregular sampling data impairs results of prestack migration, multiple attenuations, spectra estimation. Prestack 5-D volumes are often divided into sub-sections for further processing. Shot gathers are easy to obtain from irregular sampling volumes. My strategy for reconstruction is as follows: I resort irregular sampling gathers into a form of easy to bin and perform bin regularization, then utilize F-K inversion to reconstruct seismic data. In consideration of poor ability of F-K regularization to fill in large gaps, I sort regular sampling gathers to CMP and proposed high-resolution parabolic Radon transform to interpolate data and extrapolate offsets. To strong interfering noise--multiples, I use hybrid-domain high-resolution parabolic Radon transform to attenuate it. F-K regularization demand ultimately for lower computing costs. I proposed several methods to further improve efficiency of F-K inversion: first I introduce 1D and 2D NFFT algorithm for a rapid calculation of DFT operators; then develop fast 1D and 2D CG method to solve least-square equations, and utilize preconditioner to accelerate convergence of CG iterations; what’s more, I use Delaunay triangulation for weight calculation and use bandlimit frequency and varying bandwidth technique for competitive computation. Numerical 2D and 3D examples are offered to verify reasonable results and more efficiency. F-K regularization has poor ability to fill in large gaps, so I rearrange data as CMP gathers and develop hybrid-domain high-resolution parabolic Radon transforms which be used ether to interpolate null traces and extrapolate near and far offsets or suppress a strong interfere noise: multiples. I use it to attenuate multiples to verify performances of our algorithm and proposed routines for industrial application. Numerical examples and field data examples show a nice performance of our method.