Objective:To establish the methods for the determination of Mg,Al,K,Ca,Cr,Cu,Zn,As,Se,Ag,Cd,Sn,Ba,Pb,Na and Hg in water for injection. Methods:The sixteen metallic elements in water for injection were determined by ICP-MS. The collision cell technology ( CCT) was used to minimize the multiple atomic interference, and the matrix effect and signal drift were compensated by using Li, Sc, Ge, In, Ir and Bi as the internal standards and the samples were directly acidified to detect the metallic elements. Results:The detection limit range of the 16 metallic elements were from 0. 009 to 0. 165 ng·ml-1. The calibration curves showed good linearity (r≥0. 999 0). The recoveries were within the range of 80%-120%(n=6). Conclusion:The method is simple, rapid and accurate. It can be used to determine the contents of metallic elements to reduce the potential exceeding limit risk of toxic metal el-ements in water for injection. The methods also can provide reference for the more strict quality evaluation of water for injection.

The abnormality of the central noradrenergic system in Alzheimer's disease has two cases: decrease or increase. The former is easy to be understood, because it is resulted from the outstanding forfeit of the noradrenergic neurons in the nucleus locus ceruleus (nLC); but the noradrenalin concentration does not change and enen increase, it seems to disagree with the loss of the noradrenergic neurons in the nLC. This article put emphasis on it, enumerated the related evidence and analyzed the possible causes. At present time, the drugs to increase noradrenalin is used mostly in clinic. This paper summarized it and put forth our own opinions.

AIM: To observe the relationship between noradrenaline and the synaptic configuration in rat hippocampus CA3 area. METHODS: Noradrenergic system injured models were produced by injecting 6-hydroxydopamine into rats' bilateral dorsal noradrenergic bundle. Then Y-type maze tests and elicitation of P3-like were carried out respectively before and after the model was established. The parameters of synaptic configuration in the hippocampus CA3 areas were also analyzed quantitatively. RESULTS: The decreases in the thickness of postsynaptic density material, the curvature of synaptic interface and the occurrence of perforated synapses, and the increase in the width of synaptic cleft were observed. CONCLUSION: The normal noradrenalin level in hippocampus is necessary to maintain the normal synaptic interface ultrastructure in hippocampus CA3 area.

The Clinical Medicine Proficiency Test developed by the National Medical Examination Center of China in 2020 aims to assess whether clinical medical students possess the necessary medical humanities and basic medical theoretical knowledge and skills required for clinical internships. Since 2002, Japan has implemented the pre-clinical clerkship objective structured clinical examination and computer-based testing, which share similarities with China's proficiency test in terms of examination objectives, content, format, and score evaluation. Through comparing the examinations of China and Japan, this article concludes that it is necessary to learn from Japan's experience to expedite the process of promoting the Clinical Medicine Proficiency Test as an industry admission examination in China. We suggest that medical schools should keep tracking the development of the proficiency test and fully leverage its role in urging students to pay more attention to clinical internships. We also urge medical schools to establish a three-level examination system based on post competency criteria in line with the standards of the National Medical Licensing Examination to improve the quality of medical education.