[Epidemiological characteristics of novel coronavirus pneumonia in Shijiazhuang, China].

Objective: To analyze the epidemiological characteristics of an outbreak of novel coronavirus pneumonia (COVID-19) in Shijiazhuang, Hebei Province in 2021 and to provide scientific basis for developing improved strategies to prevent and control the outbreak of COVID-19. Methods: Descriptive analysis of the outbreak of COVID-19 in Shijiazhuang, Hebei Province was performed with SPSS 21.0 and Excel software. The statistical analysis of the incubation period was performed using the rstan package in R4.0.4. Results: As of February 14th 2021, a total of 942 local confirmed cases were reported in Hebei Province, 869 cases in Shijiazhuang, of which 847 cases were available for case information. This outbreak was mainly in rural areas, with the largest number of confirmed cases in Xiaoguozhuang village, 249 (29.4%); followed by Nanqiaozhai village, 128 (15.1%); and Liujiazuo village, 85 (10.0%). The outbreak lasted from January 2nd, 2021 to February 14th, 2021, and was mainly transmitted among the farmers as well as the students through dining parties, public gatherings and family contacts, showing an obvious time and occupation concentration trend. An analysis of 116 local confirmed cases in this outbreak with specific exposure time and onset time indicated that the median incubation period was 6 [interquartile range(IQR): 3.3, 10.0] days; whereas another report including 264 local confirmed cases with specific exposure time window showed that a median incubation period was 8.5 [95% confidence interval (CI): 1.8-18.8] days. Conclusions: This outbreak was mainly related to rural areas, and was associated with parties, public gatherings and family gatherings. Self-protection and isolation of key areas and populations at risk should be effectively implemented to avoid close contact and other measures to reduce the occurrence of COVID-19 aggregation. Based on the results of the incubation period of this outbreak, the isolation period could be recommended to be extended to three weeks.

[Preliminary analysis of the effects of tailor-made notched music therapy on chronic idiopathic tinnitus].

Objective: Tailor-made notched music was applied to alleviate the symptoms of chronic idiopathic tinnitus and compared its effectiveness with other existing sound treatment of tinnitus. Methods: Subjects (n=43; ears=75 )were recruited during June 2015 to October 2016 from the out-patients of our hospital. These patients had chronic (longer than 6months) and idiopathic tinnitus, with or without significant sensorineural hearing loss. In the prospective design, the patients were randomly divided into group A (treated with tailor-made notched music) and group B (treated with analogous sound masking), and received the treatment for 3 months. The tinnitus scale, tinnitus questionnaire and audiological findings were evaluated before treatment, and at one month and three months after treatment started. Results: After onemonth of treatment, the effective rate between the two groups was 40.9% and 42.9%, there was no significant difference between the two groups (χ(2)= 0.017, P=0.897). The average VAS for patients in group A showed more decrease in group A than in group B(VAS: 1.8 vs. 0.8, the percentage : 29.5% vs. 13.6%), but there was no significant difference between the two groups (t=-1.450, P=0.155). After 3 months of treatment, the effective rates were 68.2% and 23.8%, respectively. There was significant difference between the two groups (χ(2)= 8.503, P=0.004). The difference of the VAS scores between the two groups was statistically significant (t=-3.263, P=0.002), and the VAS score of group A was less.After 3 months of treatment, there was significant decreaseinthe average tinnitus loudness for patients in group A(t=5.569, P<0.01), and there was no significant changein group B(t=-0.953, P=0.374). There was also significant decreasein the scores of tinnitus handicap inventory (THI) (F=7.334, P<0.05), loudness visual analog scale (VAS) (F=20.48, P<0.001), and the proportion of patients with moderate to severe tinnitus(χ(2)=11.289, P<0.05) in the group A, and there was no significant change in group B(F=2.198, F=0.989, χ(2)=1.651; P=0.120, P=0.378, P=0.438>0.05). Conclusions: Our resultssuggest that long-term normalized listening to tailor-made notched music, can significantly reduce the perceived tinnitus loudness in varying degrees and improve the quality of life of patients. The effects and possible mechanism of this method were discussedin this paper.

Observations on ozone treatment of excess sludge.

This work experimentally studied the effects of ozonation treatment on waste sludge. During the treatment process, various parameters characterizing sludge were investigated. A substantial reduction in the volume of sludge and the release of intracellular and extracellular materials were observed. With the increase of ozone dose, the settleability and water content of sludge improved obviously, but the filterability of sludge deteriorated drastically. In addition, the evolution of particle size was evaluated, which proved the breakup of sludge flocs and cells. There existed a threshold of ozone dose which was 0.04 gO(3)/gMLSS in this work. Above the threshold, the soluble chemical oxygen demand (SCOD), protein, carbohydrate, total nitrogen and total phosphorus in supernatant increased remarkably and the electron transport system (ETS) sludge activity decreased. Organic nitrogen and organic phosphorus occupied the main part of total nitrogen and total phosphorus in the supernatant.