Objective To study the radiation dose distribution in the X-ray room,and provide the strategy of radiation protection for the medical staff and the patient’s nursing who had to enter the room while the X-ray was exposing.Methods The thermolumi-nescent dosemeters(TLDs)was placed around the center of the X-ray tube with the same level of the bed.Then,exposure parame-ters,including the X-ray tube voltage value and the field of view,were changed for different groups while exposing.All of the TLDs were taken back to the lab for analysis.Results The differences between the two groups which had the same distance in different di-rections were statistically significant (P <0.01).With the same radiographic condition and direction,the radiation dose on the site of 10 cm from X-ray tube center was the maximum,while the site of 120 cm was the minimum.With the same radiographic condition and distance,the radiation dose on the anode side of the X-ray tube in the room was relative lower,while the site behind the X-ray tube was relative higher.With the same voltage value,distance and direction,the same sites that had the smaller FOV(34 cm×34 cm) received lower radiation dose than those with larger FOV(52.6 cm× 52.6 cm).Meanwhile,the sites with the voltage of 70 kV re-ceived the lower radiation dose than that with the voltage value of 120 kV.Conclusion In the X-ray room,the medical staff and the patient’s nursing can choose the area on the right side(anode side),keep far away from the X-ray tube center,avoid the rear of the X-ray tube and the cathodic direction of the X-ray tube to reduce the radiation dose.

OBJECTIVE: To investigate the meaning of the mutation screening, prevalence, inheritance and the intervention or the prevention for the specific drugs in 10 families with non-syndrome hearing loss in Yunnan Province, China. METHOD: To do a questionnaire about the cases of ten families with non-syndrome hearing loss and to draw a detailed matriarchal family tree detailed. Following that, the A1555G mutation-positive individuals were detected and confirmed using DNA extracting, PCR amplification and sequencing for family volunteer. RESULT: There are 96 members have attended the blood collection in these ten families. Thirty-six of them had the normal hearing and 60 of them had the sensory neural hearing loss. However, 4 out of those had no A1555G point mutation, and 92 had A1555G point mutation (95.8%). While 7 of those were Heterogeneity, the rest were all homogeneous mutation. There were also 73 patients who had amino glycoside antibiotic medication history. However all the rest cases had a history of amino glycoside antibiotic medication were not clear yet. CONCLUSION The proportion of patients with drug-induced deafness is high in Yunnan province and the mutation rate of mitochondrial DNA A1555G is also high. It is worthy to do DNA 12SrRNA A1555G mutation screening for drug intervention and prevention.
Adolescent ; Adult ; Aged ; Child ; China ; epidemiology ; DNA Mutational Analysis ; DNA, Mitochondrial ; genetics ; Deafness ; epidemiology ; genetics ; Female ; Humans ; Male ; Middle Aged ; Pedigree ; Point Mutation ; RNA, Ribosomal ; genetics ; Young Adult

Objective:To compare the tropism of different adeno-associated virus (AAV) serotypes in retinal cells.Methods:The plasmids pFastBacDual-inCap and pFastBacDual-ITR-CMV-EGFP were constructed for AAV packaging with the baculovirus expression system.Recombinant adeno-associated virus type 2(rAAV2), 6, 8 and 9 serotypes were packaged, and the infectivity of rAAV was evaluated by infecting HEK293T cells at multiplicity of infection(MOI)2000.Twenty-five C57BL/6 mice were divided into five groups, with five mice per group.In the three experimental groups, both eyes of each mouse were injected 1 μl rAAV intravitreally, and 1 μl phosphate buffered saline (PBS) for the eyes of the control group.Two weeks after injection, the retinal tissues were collected for preparing flat mounts and cryosections.Enhanced green fluorescent protein (EGFP) gene expression was observed via fluorescence microscopy and laser scanning confocal microscopy.The study protocol was approved by the Ethics Committee of Suzhou Institute of Biomedical Engineering and Technology.Results:The infection efficiency of the recombinant virus to HEK293T cells was rAAV2>rAAV6>rAAV8>rAAV9, and the transduction efficiency was 39.5%, 18.4%, 8.7% and 4.6%, respectively.In mouse retinal transduction, rAAV2 and rAAV6 were highly expressed in the ganglion cells, and rAAV8 and rAAV9 were highly expressed in the retinal pigment epithelium (RPE) and photoreceptor cells.rAAV2-mediated EGFP expression in retinas was stable within three months after injection.Conclusions:Different rAAV serotypes have varying tropism and transduction efficiencies in retinal cells through intravitreal injection, rAAV2 has a high transduction efficiency and it can be stably expressed in retinas within three months after injection.

ObjectiveTo describe the epidemic characteristics of COVID-19 after policy adjustment from “Category B notifiable disease with category A management” to “Category B notifiable disease with category B management”， and to explore the protective effect of previous infection with SARS-CoV-2 on common symptoms of reinfection. MethodsHealthcare workers infected with SARS-CoV-2 in a grade A tertiary hospital in Shanghai were included in the study from December 4， 2022 to January 11， 2023. Data on demographic characteristics， clinical symptoms， medical history， and COVID-19 vaccination history were collected. We determined the epidemiological curve and characteristics， and then compared the difference in the severity of clinical symptoms between primary and reinfection subjects. ResultsA total of 2 704 cases were included in the study， of which 45 had reinfection， 605 （22.4%）were males， 608 （22.5%）were doctors， 1 275 （47.2%） were nurses， and 2 351 （86.9%） received ≥3 doses of COVID-19 vaccination. The average age of these healthcare workers was （34.9±9.1） years old. The number of cases with mild/moderate illness， asymptomatic infection， fever， headache， dry cough， expectoration， and chest tightness were 2 704 （100.0%）， 92 （3.4%）， 2 385 （88.2%）， 2 066 （76.4%）， 1 642 （60.7%）， 1 807 （66.8%）， and 439 （16.2%）， respectively. Reinfection was a protective factor for fever （OR=0.161， P<0.001）， headache （OR=0.320， P<0.001）， and peak body temperature （β=-0.446， P<0.001）. ConclusionFollowing the COVID-19 policy adjustment as a category B notifiable disease， healthcare workers at a grade A tertiary hospital in Shanghai predominantly experiences mild to moderate COVID-19 symptoms. Reinfection results in milder clinical manifestations， with a lower proportion of being asymptomatic.

Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. It is highly contagious and can cause death in severe cases. As reported by the World Health Organization (WHO), as of 6:36 pm Central European Summer Time (CEST), 12 August 2022, there had been 585 950 285 confirmed cases of COVID-19, including 6 425 422 deaths (WHO, 2022).
Humans ; COVID-19 ; SARS-CoV-2 ; Mental Health ; Cohort Studies ; Quality of Life ; China/epidemiology* ; Health Personnel ; Hospitals ; Lung