[Epidemiological characteristics of local outbreak of COVID-19 caused by SARS-CoV-2 Delta variant in Liwan district, Guangzhou].

Objective: To analyze the epidemiological characteristics of a local outbreak of COVID-19 caused by SARS-CoV-2 B.1.617.2(Delta) variant in Liwan district, Guangzhou, and provide evidence for the further prevention and control of the Delta variant of COVID-19. Methods: From May 21 to June 18, 2021, the incidence data of COVID-19 caused by Delta variant were obtained from National Notifiable Disease Report System of Chinese Disease Prevention and Control Information System and Liwan District Center for Disease Control and Prevention of Guangzhou.Frequency analysis (proportions), histograms, and percentage stacked area plots were used to describe the epidemiological characteristics of the outbreaks. The incubation period and time-varying reproduction numbers (Rt) estimations were used for the further analysis. Results: By June 18, 2021, a total of 127 COVID-19 cases caused by Delta variant was reported in Liwan district. The youngest case was aged 2 years and the oldest was aged 85 years. There were 18.9% (24/127) aged <18 years, 43.3% (55/127) aged 18-59 years, and 37.8% (48/127) aged ≥60 years, the male to female ratio of the cases was 1∶1.35 (54∶73). The cases were mainly retired people (32.3%, 41/127), the jobless or unemployed (18.1%, 23/127), and students (16.5%, 21/127). The infections mainly occurred in Baihedong (70.1%, 89/127) and Zhongnan street (23.6%, 30/127) communities in the southern area of Liwan district. The median incubation period of the Delta variant infection was 6 days (range: 1-15 days). The clinical classification were mainly common type (64.6%, 82/127). The basic reproduction number (R0) was 5.1, Rt which once increased to 7.3. The transmissions mainly occurred in confined spaces, such as home (26.8%), restaurant (29.1%), neighborhood (3.9%), and market (3.1%), the household clustering was predominant. Close contacts tracing (66.1%) and community screening (33.1%) were the main ways to find the infections. Conclusion: The COVID-19 outbreak caused by Delta variant in Liwan district of Guangzhou was highly contagious, with the obvious characteristics of household clustering and high proportions of cases in adults aged 18-59 years and elderly people aged ≥60 years.

[Characteristic analysis of organic fluorosis caused by appliying of touch screen anti-fingerprint nanocoating material].

Objective: To analysis pathogenic conditions and pathogenic characteristics of organic fluorosis caused by applying of anti-fingerprint coating material on touch screen glass of the mobile phone. Methods: To collect clinical data and analyze the causes and pathogenic characteristics of poisoning through surveying occupational health, detecting occupational hazards in the workplace, collecting clinical data and diagnosing of occupational diseases. 6 employees in workshop 1 of packaging were as the organic fluorine exdposed group, and 16 employees in other workshops were as the non-exposed group. Results: Organic fluorine chemicals (perfluoro-1, 3-dimethylcyclohexane, hexadecafluoroheptane, perfluoro-hexane, perfluoromethy lopentane, perfluoro-2-methyl-2-pentene, etc.) can be volatilized by spraying and baking of anti-fingerprint nano-coating material on touch screen. The relative percentage of volatile components in air is 85.65%. Four cases of acute poisoning were caused by organic fluorosis deposited in a dustless air conditioning workshop with poor ventilation.The clinical manifestations of the patients were acute bronchitis, pulmonary edema and/or myocarditis. The average concentration of urine fluorine in the organic fluorine exposed group was 13.7± 4.4 mmol/mol creatinine, which was 4-5 times higher than that of other non-organic fluorine exposed groups. The difference of urine fluorine level between the organic fluorine exposed group and non exposed group was statistically significant (P<0.01) . The main indicators were abnormal for the blood oxygen saturation of finger pulse under suction air, leukocytes, neutrophils, monocytes, hypersensitivec-reactive protein, procalcitonin, l-lactate dehydrogenase, forebrain diuretic natriuretic peptide, hypersensitive troponin T in the four cases. One case was myocardial ischemia, four cases had bilateral lung symmetrically exudative lesions, one case was accompanied by a small amount of pleural pericardial effusion. Conclusion: Acute organofluorine poisoning can caused by the applying of the fingerprint nano-coating material on touch screen of the mobile phone. Attention should be paid to occupational poisoning caused by the applying of the small molecular perfluoroalkanes (olefins) in new industries, new processes and new materials.

Levels and profiles of unintentionally produced persistent organic pollutants in surface soils from Shanxi province, China.

Six species of unintentionally produced persistent organic pollutions comprised of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, polychlorinated biphenyls, polychlorinated naphthalenes, hexachlorobenzene and pentachlorobenzene in soils collected from Shanxi province, China were determined. The sum toxic equivalent ranged from 0.14 to 2.20 with an average of 0.94 pg TEQ/g. Polychlorinated dibenzo-p-dioxins/furans contributed the most toxic proportion to the total toxic equivalent. CB-126 was the most toxic contributor to polychlorinated biphenyls. CN66/67 and CN73 are the dominant toxic congeners to polychlorinated naphthalenes. From the patterns, it was speculated that thermal related industries were possible sources of unintentionally produced persistent organic pollutions.

A novel locus for autosomal dominant non-syndromic deafness (DFNA41) maps to chromosome 12q24-qter.

We have studied 36 subjects in a large multigenerational Chinese family that is segregating for an autosomal dominant adult onset form of progressive non-syndromic hearing loss. All affected subjects had bilateral sensorineural hearing loss involving all frequencies with some significant gender differences in initial presentation. After excluding linkage to known loci for non-syndromic deafness, we used the Center for Inherited Disease Research (CIDR) to test for 351 polymorphic markers distributed at approximately 10 cM intervals throughout the genome. Analysis of the resulting data provided evidence that the locus designated DFNA41 maps to a 15 cM region on chromosome 12q24.32-qter, proximal to the marker D12S1609. A maximum two point lod score of 6.56 at theta=0.0 was obtained for D12S343. This gene is distal to DFNA25, a previously identified locus for dominant adult onset hearing loss that maps to 12q21-24. Positional/functional candidate genes in this region include frizzled 10, epimorphin, RAN, and ZFOC1.