In the process of enamel development, premature senescence and apoptosis of ameloblasts are important causes of hereditary enamel hypoplasia. Silence information regulator 2-related enzyme 1 (Sirt1) is a nicotinamide adenosine dinucleotide (NAD+)-dependent deacetylase that has been widely reported to be involved in the regulation of cell senescence. This paper reviews the research progress of Sirt1 regulating epithelial cell senescence, starting with the structural characteristics of Sirt1, and further expounds on the relationship between Sirt1 and senescence. When epithelial cells are stimulated, Sirt1 affects the senescence of epithelial cells in many ways, such as mitochondrial dysfunction. Sirt1 participates in regulating mitochondrial function and metabolic homeostasis, and telomere length is negatively related to senescence. Sirt1 regulates the expression of telomere reverse transcriptase needed for telomere extension, thus positively regulating telomere homeostasis. DNA damage will undergo damage repair, unrepaired DNA damage will cause cell senescence, and the Sirt1/p53 pathway can inhibit epithelial cell senescence by reducing DNA damage. Senescent cells are the source of chronic inflammation, and chronic inflammation can also promote aging in many ways. Sirt1 inhibits epithelial cell senescence by relieving inflammatory symptoms. In future research, we can focus on the effect of Sirt1 on ameloblast senescence and explore its specific mechanism of action on ameloblasts to find a breakthrough in the etiology and treatment of enamel hypoplasia.

Abstract: To investigate the changes of cerebral blood flow(CBF) in patients with type 2 diabetes mellitus(T2 DM) and its correlation with cognitive function and olfactory impairment. Methods: Cognitive function assessment and smell identification test were performed on 83 patients with T2 DM and 62 healthy controls(HC). Three-dimensional pseudo-continuous arterial spin labeling(3 D-pcASL) head images were collected from the two groups. CBF values of the cerebral cortex were compared between the patients and HC after the postprocessing. Correlations between the CBF values and cognitive function assessment and between the CBF values and smell identification test scores were analyzed as well. Results: Compared to the HC, Chinese smell identification test(CSIT), montreal cognitive assessment(MoCA), digit span test(DST), verbal fluency test(VFT) scores were lower in T2 DM patients(P<0.05).The CBF of the bilateral middle frontal gyrus in T2 DM patients was higher than that in HC group(P<0.001). The CBF of the bilateral gyrus rectus and olfactory cortex in T2 DM patients was lower than that in HC group(P<0.001). Conclusion The cognitive and olfactory function of patients with T2 DM decreased. Patients with T2 DM have abnormal perfusion in the bilateral middle frontal gyrus, gyrus rectus and olfactory cortex, revealing that CBF changes in these brain regions may be one of the causes for cognitive impairment and olfactory dysfunction in T2 DM.

OBJECTIVE To understand the present situation of hand hygiene execution rate among clinical medical personnel,and discuss a series of scientific,reasonable and practical hand hygiene intervention methods,in order to elevate the hand hygiene execution rate among medical personnel.METHODS Using the self-designed questionoaires in combination with observation on hand hygiene process and investigation of hand hygiene knowledge level among medical personnel in various departments of different levels of hospitals to assess the hand hygiene execution rate.RESULTS The investigation indicated 76.00% medical personnel have had hand hygienic knowledge training,and referred in the stipulation health drafts,the hand hygiene execution rate was 50.00-70.00%.The hand health execution rate before contact with patients was 59.82%,and after contacts with patients was 77.97%;among department the hand hygiene execution rate before contact with patients was highest in the department of pediatrics(82.78%),the lowest was in emergency department(11.11%),after contact with patients the highest was department of infectiong(100.00%),and the larest was in the internal medicine department(39.93%).CONCLUSIONS Medical personnel's hand hygiene consciousness is still weak,with lacked hand hygiene related knowledge,it is necessary to summarize a set of reasonable effective intervention plans to elevate the hand hygiene execution rate,reduce the hospital infection percentage,and lower the patient pain and the economic loss.