Zbtb34 is a novel zinc finger protein, which is revealed by biological software analysis to have 3 zinc fingers, but its functions remain unknown. In this study, mouse Zbtb34 cDNA was amplified by PCR and inserted into the plasmid pEGFP-N1 to generate Zbtb34-EGFP fusion protein. The upregulation of Zbtb34 in mouse embryonic stem cells promoted telomere elongation and increased cell proliferation. In order to understand the above phenomena, the telomere co-immunoprecipitation technique was employed to investigate the relationship between Zbtb34 and telomeres. The results indicated that Zbtb34 could bind to the DNA sequences of the telomeres. Alanine substitution of the third zinc finger abolished such binding. Since Pot1 is the only protein binding to the single-stranded DNA at the end of the telomeres, we further investigated the relationship between Zbtb34 and Pot1. The results revealed that the upregulation of Zbtb34 decreased the binding of Pot1b to the telomeres. Through the upregulation of Pot1b, the binding of Zbtb34 to the telomeres was also reduced. In conclusion, we showed that the main biological function of Zbtb34 was to bind telomere DNA via its third ZnF, competing with Pot1b for the binding sites, resulting in telomere elongation and cell proliferation.

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Biosafety laboratory is an important place to study high-risk microbes. In biosafety laboratories, with the outbreak of infectious diseases such as COVID-19, experimental activities have become increasingly frequent, and the risk of exposure to bioaerosols has increased. To explore the exposure risk of biosafety laboratories, the intensity and emission characteristics of laboratory risk factors were investigated. In this study, high-risk microbe samples were substituted with Serratia marcescens as the model bacteria. The resulting concentration and particle size segregation of the bioaerosol produced by three experimental procedures (spill, injection, and sample drop) were monitored, and the emission sources’ intensity were quantitatively analyzed. The results showed that the aerosol concentration produced by injection and sample drop was 103 CFU/m3, and that by sample spill was 102 CFU/m3. The particle size of bioaerosol is mainly segregated in the range of 3.3–4.7 μm. There are significant differences in the influence of risk factors on source intensity. The intensity of sample spill, injection, and sample drop source is 3.6 CFU/s, 78.2 CFU/s, and 664 CFU/s. This study could provide suggestions for risk assessment of experimental operation procedures and experimental personnel protection.

A large amount of surgical smoke in electrosurgery seriously deteriorates the clean environment of the operating room and can potentially harm medical staff and patients. Exploring the distribution and removal of indoor particulate matter and selecting efficient ventilation patterns are effective ways to control harmful smoke. Therefore, in this study, we combined simulations and full-scale experiments to quantitatively explore the high-concentration spatial regions of particles and compared three ventilation patterns: vertical laminar airflow (VLAF), horizontal laminar airflow (HLAF), and hybrid ventilation, wherein unidirectional airflow (UDAF) was applied to the operating table along with peripheral mixing (UDAF + mixing). We found that simple laminar flow ventilation was significantly affected by the equipment layout and air change rate (air changes per hour; ACH), and the smoke particles were distributed in large amounts in the operating area and could not be removed completely. Conversely, hybrid ventilation can work effectively, and the optimal ACH is approximately 60, which can remove nearly 72% of smoke particles. The airflow distribution in the operating room is also an important factor affecting the distribution and removal of smoke particles. Therefore, medical staff should avoid prolonged exposure to areas with high particle concentrations and particle removal paths.