Objectives: The goal of this project was to evaluate the degree of contamination of the air and lab surfaces during the extraction of RNA from COVID-19 under laboratory ventilation systems, identify operational risk areas, and provide a reference for reducing medical contamination in COVID-19 detection.Methods: Our COVID-19 testing contains the real-world test and a splash test, detected the RNA residue of COVID-19 pseudovirus on the surface of air and object with PCR.Results: Our results show that RNA extraction contamination occurs more frequently under non-negative pressure than under negative pressure. The biological safety cabinet features a system to stop contamination that may successfully halt the transmission of aerosols as well as the contamination of the experimenter's glove, which is a major source of transmission. Furthermore, UV disinfection cannot completely sterilize an area and regular and effective cleaning is also necessary.Conclusions: In summary,our study lays the foundation for efficacy evaluation of laboratory construction of positive and negative pressure systems and also elucidates the focus of laboratory contamination prevention, providing a strong anti-contamination basis for the extraction of RNA testing for the prevention and control of COVID-19 and even other respiratory transmitted diseases.

Abstract Background . To identify the clinical implications, risk factors and predictors with mixed candida/bacterial bloodstream infection (BSI) of cadiovascular patients in Guangdong Provincial People’s Hospital, Guangzhou, Guangdong, China (a third-class hospital with a strong focus on cardiovascular disease). We conducted a retrospective case-control study of patients complicated with candidaemia over the past 10-year period to identify the risk factors and clinical implications of mixed candidia/bacterial BSIs vs. monobacterial candidiasis. Method . We searched all discharged patients' diagnoses for icd codes related to candida bloodstream infection. We have made two sets of comparisons:1. Two groups of patients were compared: all cadiovascular patients with mixed candida/bacterial BSI (cases1 n=86), and all no cadiovascular patients with mixed candida/bacterial BSI (control 2 n=45); 2. Two groups of patients were compared: all patients with mixed candida/bacterial BSI (cases1 n=69), and all patients with mono candida BSI (control 2 n=62). Statistical analysis was performed using SPSS 25.0 statistical software. The independent sample t-test and chi-square analysis was used. Result . The median age of the patients who have mixed candida / bacterial BSI was 63 years old, and 70.42% of these patients were male. Cardiovascular disease was the most common underlying disease of mixed candida / bacterial BSI, followed by neurological disease, and followed by tumors and diabetes. In cases of mono candida bloodstream infection, infection with Candida tropicalis and Candida albicans dominated. In cases of mixed bloodstream infection with bacterial candida, the highest proportion is Candida albicans. In the cases of candida bloodstream infection without cardiovascular underlying disease, it is Candida tropicalis, followed by Candida albicans. Opposite, in the cases with an underlying cardiovascular disease, the highest proportion is Candida albicans. Conclusion . Our data show that older adults（age＞65 years）, men are more susceptible to candida bloodstream infections. Bacterial candida mixed bloodstream infections mostly led by staphylococcus sp. Procalcitonin（PCT）, white blood cell（WBC）, neutrophilicgranulocyte（N） were predictive for mixed bloodstream infection with bacterial candida species. Among the cases in our hospital, patients with underlying cardiovascular disease were associated with mixed bacterial candida infections.

目的 探讨肺泡灌洗液中性粒细胞比例联合革兰染色对肺炎的诊断效能.方法 回顾性纳入2018年9月至2021年5月广东省人民医院呼吸内科肺泡灌洗液送检的住院患者188例,其中肺炎患者为病例组,非肺炎患者为对照组.收集患者人口学资料、临床诊断及肺泡灌洗液中性粒细胞比例、革兰染色结果等临床信息,比较两组患者间差异,并绘制受试者工作特征曲线(receiver operating characteristic,ROC)评价支气管肺泡灌洗液(broncho alveolar lavage fluid,BALF)中性粒细胞比例和革兰染色在肺炎患者中的诊断价值.结果 病例组108例,对照组80例,其中病例组社区获得性肺炎74例,医院获得性肺炎34例.肺炎患者的肺泡灌洗液中性粒细胞比例明显高于非肺炎患者(P<0.01),肺泡灌洗液中性粒细胞比例诊断肺炎的Cut-off值为41.45,灵敏度0.750,特异度0.675,ROC曲线下面积0.728;在社区获得性肺炎(community?acquired pneumonia,CAP)和医院获得性肺炎医院获得性肺炎(hospital?acquired pneumonia,HAP)中,BALF中性粒细胞比例差异无统计学意义(P>0.05).BALF中性粒细胞比例联合镜下革兰染色诊断肺炎的Cut?off值为22.09,灵敏度0.724,特异度0.703,ROC曲线下面积为0.731.BALF中性粒细胞比例联合镜下革兰染色对肺炎诊断效能高于单一BALF中性粒细胞诊断效能.BALF中性粒细胞比例越高对肺炎的灵敏度越高.结论 BALF中性粒细胞比例联合镜下革兰染色对肺炎有一定的诊断价值.

Sepsis is a clinical syndrome caused by the host reaction disorder induced by infection, which leads to serious organ function damage. Sepsis is a serious disease with high mortality, which is the main reason of death caused by infection. Single nucleotide polymorphisms (SNP) is one of the most common genetic variants in human, and is closely related to the genetic susceptibility, early diagnosis, disease development and prognosis of sepsis. This article makes a review on the relationship between CD14, Toll like receptor (TLR), tumor necrosis factor (TNF), interleukins (IL-1 and IL-6), plasminogen activator inhibitor 1 (PAI-1), angiotensin converting enzyme (ACE) and other gene polymorphisms and genetic susceptibility of sepsis, in order to affect in sepsis on the early prediction, diagnosis, and treatment.