Numerical Study on Effects of Door-Opening on Airflow Patterns and Dynamic Cross-Contamination in an ISO Class 5 Operating Room

The contamination diffusion to the operating room when the door is open was simulated with a computational fluid dynamic(CFD) method,to give the extent of the contamination diffusion.The influence of the door-opening procedure was ignored since the door of the operating room is normally a sliding one.The flow field in the case of the 16 s course of opening the door was simulated.The simulated and the experimental results demonstrate that the extent of the contamination diffusion is around 1.5 m when there is no temperature difference between indoor and outdoor,and there is hardly any contamination diffusion when the temperature difference is 1 ℃.It can be concluded that the positive pressure difference in the operating room lost its function in preventing the contamination when the door is open.That the temperature of corridor is lower than that of operating room contributes to contamination control.Keeping 1 ℃ temperature difference between corridor and operating room and increasing positive pressure and air flow are suggested.It is more secure to set up an anteroom if persons come in or out of the operation room at the course of surgery.

Study on the Explant Disinfection of Root Culture of Hevea brasiliensis

[Objective] The aim was to look for an effective way of decreasing explants contamination in the root tissue culture of Hevea brasiliensis.[Method] In order to study root tissue culture of H.brasiliensis,new roots from forest section after treatment for one month were as explants,and 1 g/L carbendazim,75% ethanol,0.1% mercuric chloride and Yipeilong with different concentrations were used as disinfectants for roots disinfection.[Result] Before conventional disinfection,root explants were treated by 1 g/L carbendazim for 2.5 h,and disinfected by 75% ethanol for 30 s and 0.1% HgCl2 for 6 min,then cultured on the callus induction medium supplemented with 0.1% Yipeilong.The results showed that the contamination rate of explants decreased to 44.59%,and 25.60% explants survived after cultured for 30 d.[Conclusion] The study could provide theoretical foundation for the decrease of explant contamination in the root tissue culture of H.brasiliensis.

Modified Adsorption Capacity to Space Molecular Pollutant of Zeolite via Interface Engineering with Atomic Layer Deposition

When spacecraft operate in space,most organic materials will release small molecular hydrocarbons and large molecular organic gases due to gas evolution effect under high vacuum conditions.These gases can deposit on the surface of spacecraft,adversely affecting its performance.Adsorption becomes the first choice for removing such organic pollutants in the space environment.Zeolite material has a stable and dense porous structure,and has been widely used in the field of pollution adsorption.In this work,Al2O3 was deposited on the surfaces of 5A zeolite for the first time by atomic layer deposition(ALD)technology.As a result,the adsorption performance of Al2O3 coated 5A zeolite(zeolite@Al2O3)was significantly modified.The corresponding adsorption process was clarified via adsorption kinetics study.

A comparison of next-generation sequencing analysis methods for cancer xenograft samples

The application of next-generation sequencing （NGS） technology in cancer is influenced by the quality and purity of tissue samples. This issue is especially critical for patient-derived xenograft （PDX） models, which have proven to be by far the best preclinical tool for investigating human tumor biology, because the sensitivity and specificity of NGS analysis in xenograft samples would be compromised by the contamination of mouse DNA and RNA. This definitely affects downstream analyses by causing inaccurate mutation calling and gene expression estimates. The reliability of NGS data analysis for cancer xenograft samples is therefore highly dependent on whether the sequencing reads derived from the xenograft could be distinguished from those originated from the host. That is, each sequence read needs to be accurately assigned to its original species. Here, we review currently available methodologies in this field, including Xenome, Disambiguate, bamcmp and pdxBlacklist, and provide guidelines for users.

Rapid and accurate evaluation of vaporized hydrogen peroxide on the efficiency of disinfection, using a sensitive dual-channel laser scanning cytometer

Vaporized hydrogen peroxide(VHP)is a highly active disinfectant,and VHP decontamination systems have been widely applied in hospitals,microbiological laboratories,and pharmaceutical industries.However,the decomposition of VHP into non-toxic by-products is essential.Evaluation of the disinfection efficacy of VHP is crucial to ensuring the reliability of VHP disinfection and controlling microbial contamination.In this study,a rapid and sensitive strategy is proposed to evaluate the efficacy of VHP in surface disinfection by detecting the survived and killed bacteria from VHP-exposed biological indicators(BIs).A dual-channel solid-phase cytometer is designed,and fluorescent dyes are used as indicators to automatically and accurately distinguish live cells from dead cells in themixtures of bacteria.To verify the availability and effectiveness of the laser scanning cytometry,experiments on its application in estimating the efficacy of VHP disinfection practice have been carried out in this study,and its estimation effect compared with that of the traditional plate counting method.Results show that the proposed assay might distinctly identify live or killed cells labeled by green and red fluorescent dyes and examined the disinfection efficacy in 30 min by calculating the bactericidal rate.Compared with the plate counting method,the proposed approach is accurate and practical,with an average detection efficiency of 98.47%±1.55%.Moreover,an excellent correlation between the concentrations of B.subtilis var niger(ATCC 9372)measured by the proposed detection system and by the plate counting method is noticed(R2=0.9971),indicating that this approach had advantages in the detection of trace microorganisms.To summarize,the proposed strategy appears practical and significant in many fields in which microbial counting and identification are required.