Transcranial direct current stimulation (tDCS) is a brain stimulation intervention technique, which has the problem of different criteria for the selection of stimulation parameters. In this study, a four-layer real head model was constructed. Based on this model, the changes of the electric field distribution in the brain with the current intensity, electrode shape, electrode area and electrode spacing were analyzed by using finite element simulation technology, and then the optimal scheme of electrical stimulation parameters was discussed. The results showed that the effective stimulation region decreased and the focusing ability increased with the increase of current intensity. The normal current density of the quadrilateral electrode was obviously larger than that of the circular electrode, which indicated that the quadrilateral electrode was more conducive to current stimulation of neurons. Moreover, the effective stimulation region of the quadrilateral electrode was more concentrated and the focusing ability was stronger. The focusing ability decreased with the increase of electrode area. Specifically, the focusing tended to increase first and then decrease with the increase of electrode spacing and the optimal electrode spacing was 64.0–67.2 mm. These results could provide some basis for the selection of electrical stimulation parameters.
ObjectiveTo review the research progress of C5 palsy (C5P) after cervical surgery, providing new clinical intervention ideas for the C5P patients. MethodsThe relevant literature domestically and abroad was extensively consulted and the latest developments in the incidence, risk factors, manifestations and diagnosis, prevention, and intervention measures of C5P were systematically expounded. ResultsC5P is characterized by weakness in the C5 nerve innervation area after cervical decompression surgery, manifested as limited shoulder abduction and elbow flexion, with an incidence rate more than 5%, often caused by segmental spinal cord injury or mechanical injury to the nerve roots. For patients with risk factors, careful operation and preventive measures can reduce the incidence of C5P. Most of the patients can recover with conservative treatment such as drug therapy and physical therapy, while those without significant improvement after 6 months of treatment may require surgical intervention such as foraminal decompression and nerve displacement. ConclusionCurrently, there has been some advancement in the etiology and intervention of C5P. Nevertheless, further research is imperative to assess the timing of intervention and surgical protocol.
Objective To explore the expression of CD34 and polyclone carcinoembryonic antigen (pCEA) of positive and negative alpha fetoprotein (AFP) detected by puncture biopsy in human hepatocellular carcinoma (HCC) and the significance of pathological diagnosis. Methods Fifty-four HCC tissue specimens from 2013 to 2015 were collected from tumor biopsy samples which confirmed by pathology in the Central Hospital of Enshi Tujia and Miao Autonomous Prefecture. The tissue samples were divided into positive AFP group (n=33) and negative AFP group (n=21) according to the detection results of serology and immunohistochemistry analysis of AFP. Expressions of CD34 and pCEA in the fifty-four HCC specimens were detected by immunohistochemistry. Results The positvie expression rate of pCEA in the positive AFP group was 69.7%, which was significantly higher than that in the negative AFP group (38.1%) (P<0. 05). However, the difference in positive expression rate of CD34 between the positive and negative AFP groups (90.91% and 85.71%, respectively) was not significant (P>0.05). Conclusion The associated detection of AFP, pCEA and CD34 in HCC tissues might contribute to the pathological and differential diagnosis of human hepatocellular carcinoma in puncture biopsies.