Evolutionary psychology holds such an opinion that negative situation may threaten survival, trigger avoidance motive and have poor effects on the human-body function and the psychological quality. Both disgusted and sad situations can induce negative emotions. However, differences between the two situations on attention capture and emotion cognition during the emotion induction are still not well known. Typical disgusted and sad situation images were used in the present study to induce two negative emotions, and 15 young students (7 males and 8 females, aged 27 ± 3) were recruited in the experiments. Electroencephalogram of 32 leads was recorded when the subjects were viewing situation images, and event-related potentials (ERP) of all leads were obtained for future analysis. Paired sample t tests were carried out on two ERP signals separately induced by disgusted and sad situation images to get time quantum with significant statistical differences between the two ERP signals. Root-mean-square deviations of two ERP signals during each time quantum were calculated and the brain topographic map based on root-mean-square deviations was drawn to display differences of two ERP signals in spatial. Results showed that differences of ERP signals induced by disgusted and sad situation images were mainly manifested in T1 (120-450 ms) early and T2 (800-1,000 ms) later. During the period of T1, the occipital lobe reflecting attention capture was activated by both disgusted and sad situation images, but the prefrontal cortex reflecting emotion sense was activated only by disgusted situation images. During the period of T2, the prefrontal cortex was activated by both disgusted and sad situation images. However, the parietal lobe was activated only by disgusted situation images, which showed stronger emotional perception. The research results would have enlightenment to deepen understanding of negative emotion and to exploredeep cognitive neuroscience mechanisms of negative emotion induction.
Adult ; Attention ; Brain Mapping ; Cognition ; Electroencephalography ; Emotions ; Evoked Potentials ; Female ; Humans ; Male ; Occipital Lobe ; physiology ; Parietal Lobe ; physiology ; Prefrontal Cortex ; physiology

Functional imaging method of biological electrical characteristics based on magneto-acoustic effect gives valuable information of tissue in early tumor diagnosis, therein time and frequency characteristics analysis of magneto-acoustic signal is important in image reconstruction. This paper proposes wave summing method based on Green function solution for acoustic source of magneto-acoustic effect. Simulations and analysis under quasi 1D transmission condition are carried out to time and frequency characteristics of magneto-acoustic signal of models with different thickness. Simulation results of magneto-acoustic signal were verified through experiments. Results of the simulation with different thickness showed that time-frequency characteristics of magneto-acoustic signal reflected thickness of sample. Thin sample, which is less than one wavelength of pulse, and thick sample, which is larger than one wavelength, showed different summed waveform and frequency characteristics, due to difference of summing thickness. Experimental results verified theoretical analysis and simulation results. This research has laid a foundation for acoustic source and conductivity reconstruction to the medium with different thickness in magneto-acoustic imaging.
Acoustics ; Computer Simulation ; Diagnostic Imaging ; Electricity ; Electrophysiological Phenomena ; Humans ; Magnetics ; Models, Theoretical

Magnetoacoustic tomography (MAT) has some advantages such as high sensitivity and high spatial resolution. The generating mechanism of acoustic source is the research foundation of forward and inverse problems. A coustic signals were respectively simulated by using monopole and dipole radiation theory in the experimental conditions, then the differences between their acoustic pressures were discussed, and furthermore the contrast and validation were conducted by physical experiments in this study. The physical experimental results showed that acoustic waveform of MAT had a certain directivity and therefore they indicated that dipole model showed higher approximation to the real facts than monopole model. It can be well concluded that this research has cardinal significance for the accurate algorithm of MAT.
Acoustics ; Algorithms ; Tomography ; methods

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Objective To design a new frequency domain magnato-aoustic imaging system to image the conductivity of medium.Methods A continuous sine wave signal was adopted to stimulate the MAT signal. The lock-in technique was applied to measuring the amplitude and phase of the magneto-acoustic signal. The drive control program of the imaging system was designed using virtual instrument tools. The experiments were conducted on the phantom made of coper wire.Results The amplitude precision was improved up to 10-7 Pa, while the system could locate the sonic source with locating precision of millimeter.Conclusion A new magneto-acoustic imaging system is proposed with high locating precision as well as low frequency excitation, which is significative to the study on the sonic source theory and improvement of the imaging precision.

Objective To design the circuit used in drug-iontophoresis and interference electric current therapy,which is a multi-functional apparatus. Methods Controlled by singlechip,through the D/A conversion and the functional generator ICL8038,a variety of waveforms were generated. The digital potentiometer was used to amplitude modulation. After the power amplifier and isolation,the signal needed was output. Results It had multiple output channels which could be regulated and controlled independently and could produce a variety of waveforms with adjustable parameters. Conclusion The circuit can complete the drug-iontophoresis and interference electric current therapy,which has simple structure and is low cost and multi-functional. It provides a new type of circuit for the relevant instrument design.

In the non-invasive magnetic nerve stimulation of human brain, the coil of figure "8" is mostly used. The peak maximum is corresponding to the center of the coil, and the negative peak value is corresponding to the twain edges of the coil, the latter one is apt to cause abnormal nerve excitation. In this text, we put emphasis on the study of abnormal stimulation induced in magnetic stimulation and analyse the electric field intensity of the figure-8 coil. Aiming at the large negative value of intensity, we develop a new structure coil to restrain abnormal stimulation. Theoretical simulation is demonstrated here also.
Computer Simulation ; Electric Stimulation ; instrumentation ; methods ; Electromagnetic Fields ; Electromagnetic Phenomena ; instrumentation ; Equipment Design

Objective To observe the meshed capillary pattern(CP)on the surface of colorectal lesions by narrow-band imaging system with magnifying endoscopy(NBI-ME),and to distinguish neoplasm from non-neoplasm by the change of capillary patterns.Methods A total of 144 colorectal lesions in 102 patients detected by conventional colonoscopy were evaluated by NBI-ME to observe the CP on surface,and by staining magnifying colonoscopy to observe the pit pattern.Results All lesions were resected endoscopically (129/144)or by surgery(15/144),and the pathological evaluation diagnosed 30 cases of non-neoplasm (including 20 cases of hyperproliferative polyps and 10 of inflammatory polyps)and 1 14 cases of neoplasm (including 95 cases of adenoma and 19 cases of adenocarcinoma).The diagnostic accuracy rate,sensitivity and specificity of conventional colonoscopy were 75.7%,85.1%and 40.O%,respectively,which were significantly lower than those of NBI-ME and staining magnifying colonoscopy(P＜0.005),while there was no significant difference between NBI-ME and staining magnifying colonoscopy.The CP of type Ⅰ,Ⅱ,Ⅳ and Ⅵa were totally correspondent with pit pattern of type Ⅰ,Ⅱ,Ⅳ and ⅤI. Conclusion NBI-ME findings of colorectal lesions correlated with those of staining magnifying colonoscopy.These two techniques are both helpful in differentiating colorectal neoplasms from non-neoplasms.

Objective To compare a novel mirror-overlap method with the traditional manual measurement and the subjective assessment in assessing breast symmetry after oncoplastic surgery.Methods 59 patients with breast cancer who underwent conservation/reconstruction surgery were recruited.The post-operative assessment for breast symmetry was conducted using manual measurement,subjective assessment by the patient,their family member and a nurse,and the mirror-overlap method respectively.The latter method involved using the Photoshop to assess the area differences in breast outlines and shadows created by a flashlight when bilateral images were overlapped in the axis of midline.Results The distance differences between bilateral breasts measured using manual method were negatively correlated with symmetric coefficients in the mirror-overlap method (P＜0.05).There was a positive correlation between the average scores in the subjective assessment and symmetric coefficients of mirror-overlap method (P＜0.05).Conclusion The mirror-overlap method is an easy,feasible and cheap method which collects 3D breast information and provides an effective approach to assess breast symmetry after oncoplastic surgery.

Objective:To investigate the etiology of pleural effusion in hospitalized children in Beijing Children′s Hospital.Methods:Clinical information of children with pleural effusion admitted to Beijing Children′s Hospital Affiliated to Capital Medical University from January 2016 to December 2018 was retrospectively analyzed.According to the etiology, the children were divided into infection group (parapneumonic pleural effusion, tuberculous pleurisy and empyema) and non infection group.According to the age, the children were further divided into ≤ 3 years old, >3-7 years old and > 7 years old groups.Classification of statistics was performed, and the etiology of pleural effusion were retrospectively analyzed.Results:Among the 1 165 children with pleural effusion, 746 cases(64.0%) were infected with pleural effusion, 697 cases (697/746, 93.4%) of who were parapneumonic effusion.In patients with parapneumonic effusion, 457 cases (61.3%) had Mycoplasma pneumonia (MP) infection.Infectious pleural effusion was more common in children >7 years old(339/479 cases, 70.8%), while non-infectious pleural effusion was prevalent in children under 3 years old(188/324 cases, 58.0%). The difference was statistically significant ( χ2=96.33, P<0.05). Among the patients with non-infectious pleural effusion, 239 cases (239/419 cases, 57.0%) had multi-system diseases and 97 cases (97/419 cases, 23.2%) had malignant pleural effusion.All the 18 deaths were non-infectious pleural effusion. Conclusions:The leading reason for pleural effusion in children is infection.The most prevalent symptom is parapneumonic effusion, which is mainly caused by MP.