ABSTRACT
Objective To investigate the relationship between different brain developmental stages and changes of cognitive function in rats. Methods 1-month, 2-month and 8-month-old rats were selected to imitate the juvenile, adolescent and adulthood, respectively, and their behavioral functions were compared. The reward operant conditioning and Morris water maze task were used to investigate the differences in exploration interest, executive and recognition ability, spatial learning and memory of the rats at different ages. Results In the reward operant conditioning and Morris water maze task, there was no significant difference in the cognitive function between 1-month and 2-month-old rats. In the reward conditioning phase, the nose pokes numbers of 8-month-old rats were significantly decreased compared with the 1-month-old rats (P＜ 0. 01). There was no significant difference in nose pokes accuracy. During the operant conditioning phase, the lever press numbers and accuracy of 8-month-old rats were significantly decreased ( P ＜ 0. 05 or P ＜ 0. 01) and the press latency was longer (P ＜ 0. 05). At the phase of visual identification, the press and reward numbers, and the visual identification index were significantly decreased ( P ＜ 0. 05 or P ＜ 0. 01). In the Morris water maze test, compared with the 1-month-old rats, the total swimming distance and escape latency of the 8-month-old rats were significantly increased (P＜ 0. 05), as well as average swimming speed ( P ＜ 0. 05 or P ＜ 0. 01) in spatial learning phage. In spatial memory phage, the swimming distance and time spent in the target quadrant were obviously decreased (P＜ 0. 01). Conclusions The cognitive functions of rats at different brain developmental stages are different. The juvenile and adolescent rats have similar cognitive functions, but 8-month-old adult rats appear decline in the exploration interest, executive and recognition ability, and spatial learning and memory function.
ABSTRACT
Objective To evaluate the effect of damped least-square algorithm on the identification of focal bidirectional electrical impedance perturbation in the intracranial area, and to analyze the influence of this kind of perturbation on the reconstruction quality of electrical impedance tomography. Methods Focal bidirectional electrical impedance perturbation was built based on the three-dimensional model and damped least-square algorithm was introduced into imaging. The position error and resolution were used to evaluate the imaging performance.Results When the focal electrical impedance perturbation existed,the target whose conductivity varied greatly or volume was large was more likely to be identified in the images while the target with smaller volume or variable conductivity presented in the reconstruction image was not obvious. It's pointed out that it may cause reconstruction images in some cases could not truly reflect the location and change information of the object of primary cerebral hemorrhage.At the same time,it affected the reconstruction precision,causing the position error and resolution with large fluctuation. Conclusion In reconstruction algorithm linearity correct matrix introduced for bidirectional electrical impedance perturbation contributes to enhancing the recognition of bidirectional perturbation, so that the characterization of the electrical impedance imaging can be augmented for clinical intracerebral hemorrhage.
ABSTRACT
Preimplantation Genetic Diagnosis(PGD) is a pre-gestational diagnostic technique used to identify genetic defects in embryos created through in vitro fertilization prior to transfer into the uterus.It is currently the only option available to avoid the dilemma of a pregnancy termination due to unfavorable prenatal diagnosis of high risk genetic diseases,however,the limitation of this technique could result in uncertain results.To avoid ethics disputes,patients must undergo a medical informed consent process to fully understand the risks prior to undergoing PGD.This process is often hampered by the patients' restricted recognition ability.Here we discuss possible strategies to help patients completely comprehend the critical issues relating to PGD,including comprehensiveness of PGD related information,and all possible benefits and risks of currently available operational and detection techniques.Based on this, It is necessary to sign a detailed medical informed consent according to different inherited disease.