Post-traumatic stress disorder(PTSD)is a severe mental disorder that significantly impacts an indi-vidual's health,with its primary symptom being fear-based memories.In the pathological state of PTSD,fear-based memo-ries are prolonged and intensified by certain physiological mechanisms.Therefore,expediting the extinction of fear-based memories and preventing their excessive consolidation are crucial for successful treatment.Recently,researchers have dis-covered that ketamine,beyond its role as an anesthetic,also plays a substantial part in regulating fear-based memories.This paper aims to elucidate the role of ketamine in modulating conditioned fear-based memories across various time frames and brain regions,as well as the associated molecular mechanisms.Furthermore,it seeks to clarify the specificity of dif-ferent molecular mechanisms in distinct time frames of fear-based memories and assess whether ketamine could be a prima-ry medication for treating PTSD.

Post-traumatic stress disorder(PTSD)is a severe mental disorder that significantly impacts an indi-vidual's health,with its primary symptom being fear-based memories.In the pathological state of PTSD,fear-based memo-ries are prolonged and intensified by certain physiological mechanisms.Therefore,expediting the extinction of fear-based memories and preventing their excessive consolidation are crucial for successful treatment.Recently,researchers have dis-covered that ketamine,beyond its role as an anesthetic,also plays a substantial part in regulating fear-based memories.This paper aims to elucidate the role of ketamine in modulating conditioned fear-based memories across various time frames and brain regions,as well as the associated molecular mechanisms.Furthermore,it seeks to clarify the specificity of dif-ferent molecular mechanisms in distinct time frames of fear-based memories and assess whether ketamine could be a prima-ry medication for treating PTSD.

To investigate the temporal trend of antibiotic use among children in Shanghai from 2017 to 2020. The stratified cluster sampling method was used to establish a dynamic cohort of healthy children based on primary schools in Changning District, Shanghai. In the cohort, there were 282 children from 2017, 287 children from 2018, 294 from 2019 and 301 from 2020. A total of 700 children aged 7-11 years were included in the study. The basic information and antibiotic use of children were investigated by questionnaire every year, and their height and weight were measured at the same time. Chi-square test was used to analyze the difference of antibiotic use rate in each year and generalized estimation equation was used to analyze the temporal trend of antibiotic use. The results showed that the use rates of all antibiotics, cephalosporins, azithromycin and other antibiotics (including penicillin, lincomycin, quinolones, etc.) of children between 2017 and 2020 were 15.6%, 10.5%, 2.7%, and 2.4%, respectively. In 2017, 2018, 2019, and 2020, there were significant differences for the use rates of total antibiotics and other antibiotics in children ( P=0.033, P=0.040), and there were no significant differences for the use rates of cephalosporins and azithromycin ( P=0.274, P=0.455). After adjusting for children′s basic characteristics, the generalized estimation equation showed that the annual use rate of all antibiotics, cephalosporins, and other antibiotics decreased over time.

To investigate the temporal trend of antibiotic use among children in Shanghai from 2017 to 2020. The stratified cluster sampling method was used to establish a dynamic cohort of healthy children based on primary schools in Changning District, Shanghai. In the cohort, there were 282 children from 2017, 287 children from 2018, 294 from 2019 and 301 from 2020. A total of 700 children aged 7-11 years were included in the study. The basic information and antibiotic use of children were investigated by questionnaire every year, and their height and weight were measured at the same time. Chi-square test was used to analyze the difference of antibiotic use rate in each year and generalized estimation equation was used to analyze the temporal trend of antibiotic use. The results showed that the use rates of all antibiotics, cephalosporins, azithromycin and other antibiotics (including penicillin, lincomycin, quinolones, etc.) of children between 2017 and 2020 were 15.6%, 10.5%, 2.7%, and 2.4%, respectively. In 2017, 2018, 2019, and 2020, there were significant differences for the use rates of total antibiotics and other antibiotics in children ( P=0.033, P=0.040), and there were no significant differences for the use rates of cephalosporins and azithromycin ( P=0.274, P=0.455). After adjusting for children′s basic characteristics, the generalized estimation equation showed that the annual use rate of all antibiotics, cephalosporins, and other antibiotics decreased over time.

Objective To learn about the current situation and trends of novel coronavirus diseases 2019 (COVID-2019) in foreign countries. Methods The data on confirmed COVID-2019 cases were collected between January 20, 2020 and February 18, 2020 and by age, sex, nationality, contact history, region, and country were performed stratified analysis and onset time analysis. Results From January 20th to February 18th, the cumulative number of confirmed cases of COVI D-2019 abroad was 804. Excluding the 454 cases on the 'Diamond Princess' cruise ship in Japan, the daily number of new cases fluctuated, showed a trend of rising first and then maintaining a steady trend. The peak date for new cases was on February 1, with the number of cases reaching 26. The confirmed cases were mainly concentrated in Asian countries, but also distributed in Europe, North America, Oceania and Africa. As of February 15, there was no more increase reported in the number of countries where confirmed cases occurred after reaching 25. Among these countries, Singapore, Japan, and Thailand were with the highest number of cases, with 77, 65, and 35 cases, respectively. In accordamce to available information on confirmed cases, the cases with history of exposure to confirmed cases were more than those with history of living or traveling in Hubei. And more cases were non-Chinese nationalities, 40 years old and above, and males . Conclusion The novel coronavirus has transmitted abroad, and produced second-generation cases. Although the incidence is low abroad , its trend fluctuates greatly, so sufficient attention must be paid to the possibility of further transmission.