Development of a mobile personnel radiation protection equipment / 中国辐射卫生

Objective To design a mobile personnel radiation protection equipment for operation in environments with high radiation such as spent fuel reprocessing plants, to achieve simultaneous protection against γ radiation, neutron radiation, and radioactive aerosol, to reduce the internal and external exposure dose of radioactive workers, and to meet the requirement of operation for two hours. Methods The core parts of the mobile personnel radiation protection equipment included a shielding chamber and a respiratory maintenance system. An automated chassis was used for the movement and lifting of the shielding chamber. MCNP software was used to simulate and calculate the protective effects of shielding chamber made of different materials and material thicknesses. Experimental verification of the shielding chamber design was conducted. Mathematical models were established to describe the variations in the content of various gases in the chamber with personnel operation time. A respiratory maintenance system, a harmful gas absorption device, and an automated mobile chassis were designed. Results The shielding chamber made of polyethylene with a thickness of 80 mm achieved an 80% neutron shielding rate. The respiratory maintenance system could support workers for 2 hours of operation inside the equipment. The mobile chassis allowed operation of the equipment with one person. Conclusion This mobile personnel radiation protection equipment can solve the problem in simultaneous protection against γ radiation, neutron radiation, and radioactive aerosol. The equipment can provide radiation protection for radioactive workers, reduce exposure dose, and reduce personnel burden. This system provides technical means for the operation and maintenance of equipment in high-radiation sites such as spent fuel reprocessing plants.

Two golden hamster models of hypervirulent Klebsiella pneumoniae respiratory infection:a comparative study / 军事医学

Objective To establish two golden hamster models infected with hypervirulent Klebsiella pneumoniae via aerosolized intratracheal(i.t.)and intranasal(i.n.)inoculation,and compare their properties.Methods Golden hamsters of 4 to 5 weeks old were exposed to K.pneumoniae NTUH-K2044 via i.t.route and i.n.route respectively.The survival of these golden hamsters was observed and recorded within 14 days of infection before the 50%lethal dose(LD50),survival rate,bacterial respiratory deposition rate,lung bacterial load and histopathology of the infected golden hamsters in the two groups were detected.Results The LD50 of the i.t.route(3×104 CFU)was lower than that of the i.n.route(7×105 CFU)in golden hamsters.After 4×106 CFU NTUH-K2044 infection,the golden hamsters in the i.t.group had 96.46%of the bacteria deposited and colonized in the lung,developed lobar pneumonia and died without exception within 4 days of infection,while those in the i.n.group had 95.62%of the bacteria deposited in the mouth and nose initially before the bacteria moved down to the trachea for colonization and were cleared out gradually.This group mainly acquired bronchopneumonia with relatively mild lung lesions,with a 14-day survival rate of 70%.Conclusion Inoculation routes can make a difference to the disease type of respiratory tract infections in animal models.The i.t.route mainly causes lobar pneumonia with severe lung lesions,while the i.n.route leads to bronchopneumonia with mild lung lesions.The two animal models established above may be utilized for pathogenesis investigation and treatment efficacy evaluation of Klebsiella pneumoniae.

Construction and characterization of a mouse model of pneumonia caused by highly virulent and multi-drug resistant Pseudomonas aeruginosa / 军事医学

Objective To establish an inhalation infection pneumonia model of C57BL/6J mice with highly virulent and multi-drug resistant Pseudomonas aeruginosa(PA)strain F291007,and to study the microbiological,pathological and immunological characteristics of this model.Methods The strain F291007 was isolated and identified before the bacterial suspension was administered to the mice via aerosolized intratracheal inoculation to establish the pneumonia infection model.In the course of infection,the conditions and survival of the mice were observed,and the bacterial loads,the histopathological states and the cytokine expression levels in the major organs were detected.Finally,three key cytokines were blocked to observe the survival of mice.Results The strain F291007 was isolated and identified.After lethal dose infection,all the mice died within 24 h.After sub-lethal dose infection,a large number of immune cells in the body were capable of phagocytosis and killing of invading pathogens,which was manifested as rapid clearance of bacteria in lungs and the exponential decrease of bacterial load with the passage of time.The pathological changes in lungs were most severe at 1 to 3 days but gradually recovered.After infection,interleukin-6(IL-6),IL-17A and tumor necrosis factor-α(TNF-α)in alveolar lavage fluid and serum were significantly increased at 1 to 3 days.After blocking of these three cytokines with specific antibodies,the survival rates of infected mice decreased significantly.Conclusion A mouse model of gradually-recovered pneumonia infection caused by PA inhalation has been established,suggesting that the first one to three days are critical to immune response after infection through multiple indicators.This mouse model can be used for research on the pathogenesis,immunoregulation and treatment evaluation of highly virulent and multi-drug resistant PA inhalation pneumonia infection.

Kuanxiong Aerosol Regulates TLR4/MyD88/NLRP3/Caspase-1 Pathway to Reduce Cardiomyocyte Injury in Myocardial Infarc-tion Rats / 浙江中医药大学学报

[Objective]To investigate the effects of Kuanxiong aerosol(KXA)on pyroptosis and inflammatory response in isoproterenol(ISO)-induced myocardial infarction(MI)rats,and its effect on the key pathway of pyroptosis Toll-like receptor 4(TLR4)/myeloid differentiation primary response gene 88(MyD88)/NOD-like receptor pyrin domain containing 3(NLRP3)/cysteinyl aspartate specific proteinase-1(caspase-1).[Methods]Thirty male Wistar rats were randomly divided into five groups,6 rats in each group,as control group(0.9％sodium chloride solution),model group(ISO 120 mg·kg-1),isosorbide mononitrate(IMSN)group(ISO 120 mg·kg-1+IMSN 5 mg/kg·d),KXA low dose group(ISO 120 mg·kg-1+KXA 0.1 mL/kg·d),and KXA high dose group(ISO 120 mg·kg-1+KXA 0.3 mL/kg·d),gave continuous intragastric administration for 14 days,and intraperitoneal injection of ISO on the 13th and 14th day.After the last intervention,collected heart tissues and blood under anesthesia.Enzyme-linked immunosorbent assay(ELISA)was performed to investigate the expression of creatine kinase-MB(CK-MB)and cardiac troponin T(cTnT),as well as serum inflammatory indicators such as interleukin-1β(IL-1β),interleukin-18(IL-18),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α).The histopathological changes in heart tissue were evaluated using hematoxylin-eosin(HE)staining,and RNA-sequencing was used to detect the differential expression genes among groups.And the expression of the pyroptosis relevant protein was detected by Western blot.[Results]The results of the ELISA showed that CK-MB and cTnT expression in model group were significantly higher than those in control group(P＜0.01),which meant successful model construction.Pathological staining results showed disordered and fractured muscle fibers were significantly improved after KXA and IMSN intervention.RNA-seq results showed there were 2 646 different genes between model group and control group,while 714 other genes were in KXA and model group.After analyzing these two compared groups,it found that there were 130 up-regulated genes and 7 down-regulated genes;among them,inflammation related TLR4 pathway was significantly enriched.Furthermore,compared with model group,the expression of inflammatory factors IL-1β,IL-18,IL-6 and TNF-α decreased significantly in KXA groups and IMSN group(P＜0.01,P＜0.05),and Western blot showed that the protein expression of TLR4,MyD88,phospho-nuclear factor-KB(p-NF-KB)p65,NLRP3,cleaved cysteinyl aspartate specific proteinase-1(cleaved caspase-1)and Gasdermin D-N(GSDMD-N)increased significantly in model group while significantly down-regulated in KXA groups and IMSN group(P＜0.05,P＜0.01).[Conclusion]KXA can improve myocardial ischemia,reduce cardiac damage,and inhibit cardiomyocyte pyroptosis and inflammatory response,the mechanism may be related to regulating the TLR4/MyD88/NLRP3/caspase-1 signaling pathway.

Antimicrobial Efficacy of the Use of Mouthwash with Cetylpiridinium Chloride for Aerosol Producing Procedures. A Systematic Review / Eficacia antimicrobiana del uso del enjuague bucal con cloruro de cetilpiridinio en procedimientos que generan aerosoles. Revisión sistemática

Abstract The present research aims to determine the antimicrobial efficacy of the mouthwashes based on cetylpyridinium chloride (CPC), before aerosol producing dental procedures. A data search was performed during August 2021 in five databases MEDLINE (PubMed), SCOPUS, SCIELO, Cochrane Central Register of Controlled Trials (CENTRAL) and Google Scholar. Randomized clinical trials (RCTs) were included based on the PICO question, comparing the efficacy of the mouthwashes based on cetylpyridinium chloride (CPC), versus other mouthwashes and water, before aerosol producing dental procedures, papers in English, Spanish and Portuguese were included without time limits. The risk of the included studies was evaluated with the tool RoB 2.0. Number of registration PROSPERO N° CRD42021275982. 120 papers were obtained in the preliminary search, discarding those that didn't comply with the selection criteria, leaving only 3 studies. These papers reported the use of cetylpyridinium chloride (CPC) was effective for the reduction of bacteria during the ultrasonic prophylactic procedure. The use of CPC mouthwashes previous to the dental treatment with ultrasonic prophylaxis showed only antibacterial capacity.

Resumen El presente trabajo de investigación tiene como objetivo determinar la eficacia antimicrobiana de los colutorios a base de cloruro de Cetilpiridinio (CPC), previo a tratamientos dentales que generen aerosol. Se realizó una búsqueda bibliográfica hasta agosto del 2021 en cinco bases de datos: MEDLINE (vía PubMed), SCOPUS, SCIELO, Cochrane Central Register of Controlled Trials (CENTRAL) y Google Scholar. Se incluyeron ensayos clínicos aleatorizados (ECAs), basándose en la pregunta PICOS, que compare la eficacia del colutorio a base de cloruro de Cetilpiridinio (CPC) con otro colutorio, placebo o agua, previo a un tratamiento dental que genere aerosol, en los idiomas español, inglés o portugués y sin límite de tiempo. El riesgo de los estudios incluidos se evaluó con la herramienta RoB 2.0. Número de registro PROSPERO N° CRD42021275982. Se obtuvo un total de 120 artículos en la búsqueda preliminar, descartando aquellos que no cumplían con los criterios de selección, quedando sólo 3articulos. Estos artículos informaron que el uso de CPC es efectivo para la reducción de bacterias durante el procedimiento de profilaxis con ultrasonido. El uso de los enjuagues bucales a base de CPC previo al tratamiento dental de profilaxis con ultrasonido sólo tiene eficacia antibacteriana.

Virus aerosol transmission, dispersion, and infection probability simulation: A case study in subway carriages / 环境与职业医学

Background Subways are typical congregate settings and may facilitate aerosol transmission of viruses. However, quantified transmission probability estimates are lacking. Purpose To model spread and diffusion of respiratory aerosols in subways by simulation and calculation of infection probabilities. Methods The internal environment of carriages of Shanghai Metro Line 10 was used to establish a study scene. The movement of tiny particles was simulated using the turbulent model. Trend analysis of infection probabilities and viral quantum doses was conducted in a closed subway carriage scene by a quantum emission-infection probability model. Results Under a typical twelve-vent air conditioning configuration, respiratory droplet aerosols within a subway carriage dispersed rapidly throughout various regions due to airflow, with limited short-term diffusion to other carriages. Concurrently, owing to the uncertainty of airflow patterns, the airflow might circulate and converge within carriages, causing delayed outward dispersion or hindered dispersion of droplet aerosols upon entry into these zones. Passengers boarding the carriage could exacerbate the formation of these zones. When the air conditioning system functioned adequately (air exchange rate=23.21 h−1), the probability of a virus carrier transmitting the virus to other passengers within the same carriage via aerosol transmission was approximately 3.8%. However, in the event of air conditioning system failure (air exchange rate=0.5 h−1), this probability escalated dramatically to 30%. Furthermore, a super-spreader (with virus spreading exceeding 90% of the average) elevated the infection probability to 14.9%. Additionally, due to the complexity of turbulence within the carriage, if local diffusion occurred in 1/2 zones of a carriage, the anticipated infection probability would increase to 8.9%, or during the morning or evening rush hours leading to elevated aerosol concentrations, the infection probability would rise to 4.7%. The subway transmission probability for common coronaviruses diminished to as low as 0.9%. Conclusion Combined computational fluid dynamics and infection probability analysis reveals that in the prevalent twelve-vent air conditioning configurations, despite being a major transportation hub with substantial spatial-temporal overlap, the internal space of subway carriages exhibits a certain level of resistance to virus aerosol transmission owing to built-in ventilation capabilities. However, turbulence and passenger positioning may lead to localized hovering of droplet aerosols, thereby increase the risk of virus transmission. Furthermore, super-spreaders, poor operational status of built-in air conditioning system, and high passenger volume at morning or evening peak hours exert profound effects on virus transmission and infection probability.

Research progress on health risks of aerosol microorganisms / 上海预防医学

Aerosol microorganisms are important constituents of aerosols. They participate in physical and chemical reactions in the air and are also closely related to disease transmission and human health. With the SARS-CoV-2 pandemic， aerosol microorganisms have become a public health topic of great concern. Studying the composition and influencing factors of the air microbiome therefore has significant public health implications. Due to the limitations of traditional technologies for sampling and determination， the aerosol microbiome has not been fully understood. However， with the development and maturity of high-throughput sequencing technology， the aerosol microbiome has shown promising research prospects. This article reviews the composition， characteristics， detection methods and influencing factors of aerosol microorganisms， providing basic knowledge for further research on the air microbiome. In-depth research on microbial aerosols has significant implications on urban air quality control， national security and public health.

Occupational protection effect of two protective devices for manual cleaning and oiling of dental handpieces on operators / 中华劳动卫生职业病杂志

Objective: To explore the occupational protective effect of different protective devices on the operators during manual cleaning and oiling of dental handpieces, and to provide a basis for the selection of appropriate protective methods. Methods: From November 2020 to December 2021, 20 high-speed dental handpieces of the same brand were selected and randomly divided into disposable protective bag group and small aerosol safety cabinet group by drawing lots, with 10 in each group. After recording the model, they were distributed to the clinical fixed consulting room for use, and were collected by specially-assigned personnel every day for manual cleaning under the protection of the two devices. By measuring the number of airborne colonies, the concentrations of particulate matter and the satisfaction of operators, the occupational protection effect of the two protective devices on operators was evaluated. Results: Under the protection of the two devices, the average number of airborne colonies after operation was less than 1 CFU/ml. When no protective device was used, the number concentration of particulate matter produced during operation was (21595.70±8164.26) pieces/cm(3). The number concentrations of particles produced by disposable protective bag group [ (6800.24±515.05) pieces/cm(3)] and small aerosol safety cabinet group [ (5797.15±790.50) pieces/cm(3)] were significantly lower than those without any protective device (P<0.001). The number concentration of particle matter of small aerosol safety cabinet group was significantly lower than that of disposable protective bag group (P<0.001). In the satisfaction evaluation of operators, small aerosol safety cabinet group [ (3.53±0.82) points] was significantly better than disposable protective bag group [ (2.23±1.10) points] (P<0.001) . Conclusion: The use of small aerosol safety cabinet during manual cleaning and oiling of dental handpieces has good protective effect, superior safety performance and strong clinical applicability, and has advantages in occupational protection of clinical operators.

Analysis of 134Cs, 137Cs, and 60Co in aerosol samples: An intercomparison among laboratories / 中国辐射卫生

Objective To improve the analysis of 134Cs, 137Cs, and 60Co in aerosol samples by the national key radiation environment laboratories. Methods Intercomparison of analysis results of 134Cs, 137Cs, and 60Co in standard aerosol samples was performed among the national key radiation environment laboratories according to Gamma spectrometry method of analyzing radionuclides in biological samples (GB/T 16145-1995 ), and the intercomparison results were evaluated by the standard deviation. Results Six laboratories were involved in the intercomparison. For 134Cs, 50% of the laboratories showed a relative deviation less than 10%, and 50% showed a relative deviation of 10%-20%. For 137Cs, 33.3% of the laboratories showed a relative deviation less than 10%, and 76.7% showed a relative deviation of 10%-20%. For 60Cs, all laboratories showed a relative deviation less than 10%. The overall intercomparison results were acceptable. Conclusion The laboratories in this intercomparison show generally good results.

Monte Carlo simulation of α recoil migration of plutonium aerosol / 中国辐射卫生

Objective To evaluate the migration of plutonium aerosol caused by α recoil. Methods In this paper, the recoil deposition and Brownian motion of plutonium-containing nanoaerosols were simulated by Monte Carlo method. The recoil angle and the vertical first landing time of Brownian motion in the process of settling were sampled, and then the lateral displacements of Brownian motion were sampled to determine the final settling position of aerosol. Results For aerosols with particle sizes of 10-50 nm, the maximum migration distance of a single recoil settling was 1.39 μm. Brownian motion increased the migration capacity. Although there was a high likelihood that aerosols settled within 100 μm, there remained a slight probability of long-term suspension in the air. Conclusion The α recoil is one of the mechanisms of plutonium aerosol migration. An important mechanism for long-distance migration of nanoaerosols is that Brownian motion after recoil may cause them to suspend for a long time.

Efficacy and safety of aerosol inhalation of polycolistin B in patients with severe pneumonia combined with mechanical ventilation / 中国药房

OBJECTIVE To investigate the efficacy and safety of aerosol inhalation of polycolistin B in the treatment of severe pneumonia combined with mechanical ventilation， and to provide a reference of real-world data for clinical drug therapy. METHODS A retrospective cohort study was conducted to analyze the clinical data of 87 patients with severe pneumonia combined with mechanical ventilation at the First Affiliated Hospital of Shandong First Medical University from January 2021 to February 2023. According to route of administration， all patients were divided into combined group （24 cases， receiving aerosol YXH2021ZX013） inhibition of polycolistin B combined with intravenous dripping） and routine group （63 cases， intravenous dripping of polycolistin B alone）. The differences in efficacy （mortality，clinical response rate and bacterial clearance rate）and safety （elevated serum creatinine， bronchospasm and skin pigmentation） were compared between two groups； the influential factors of primary outcome index as mortality were analyzed through univariate analysis and multivariate Logistic regression analysis. RESULTS In terms of efficacy， there were no statistical differences in mortality（37.50% vs. 41.27%， P＝0.749）， clinical response rate （54.17% vs. 55.56%， P＝0.907） and bacterial clearance rate （45.83% vs. 44.44%， P＝0.907） between the two groups. In terms of safety， the incidence of bronchospasm in the combined group was significantly higher than that of the routine group （12.50% vs. 0， P＝0.028）， but the differences in incidence of elevated serum creatinine and skin pigmentation between two groups were not statistically significant （P＞0.05）. Univariate analysis showed that the moralities were higher in the case of infected with Acinetobacter baumannii， Klebsiella pneumoniae and combined use of quinolones （P＜0.05）； multivariate Logistic regression analysis showed that infection with A. baumannii （OR＝3.36， P＝0.014） and combined use of quinolones （OR＝3.54， P＝0.013） were independently associated with mortality （P＜0.05）. CONCLUSIONS For severe pneumonia patients with mechanical ventilation， intravenous dripping of polycolistin B combined with aerosol inhalation does not show superior efficacy compared with intravenous dipping of polycolistin B alone， but significantly increases the incidence of bronchospasm. Infection with A. baumannii and combined use of quinolones are independent risk factors for the increase of mortality.

Epidemiological investigation of a cluster of COVID-19 in badminton venues / 预防医学

Objective@#To perform an epidemiological survey of the first case with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Pinghu City of Jiaxing City, Zhejiang Province on March 13, 2022, so as to provide insights into the management of coronavirus disease (COVID-19) epidemics. @*Methods@#According to the requirements of the Protocol on Prevention and Control of COVID-19 (8th Edition), epidemiological investigations were performed among 39 cases with SARS-CoV-2 infections in Pinghu City from March 13 to 20, 2022. Cases' demographics, clinical symptoms, history of immunization and exposure were collected, and close contacts were identified. Pharyngeal swabs were sampled from infected cases for detection of SARS-CoV-2 nucleic acid and whole-genome sequencing, and the source of infection and transmission route were investigated. @*Results@#The index case for this COVID-19 epidemic was an imported case from Shanghai Municipality, who infected 6 persons via aerosol transmission when playing in the badminton venue of Pinghu National Fitness Center on March 9; subsequently, one of these infected cases infected another 18 persons when playing in the badminton venue of Jiadian Village Resident's Fitness Center in Zhapu Township on March 12. Sixteen confirmed cases were reported, and all cases were mild; another 23 asymptomatic cases were diagnosed, with no death reported. This epidemic occurred from March 11 to 20, with 3 generations of spread and a median incubation period of 3 days. The SARS-CoV-2 infected cases had a median age of 33.5 (interquartile range, 12.0) years and included 36 cases with a history of COVID-19 vaccination. There were 16 cases with fever, cough, runny nose and sore throat, and 13 cases with imaging features of pneumonia. The effective reproductive number (Rt) of the COVID-19 epidemic was 7.73 at early stage, and was less than 1 since March 21. Whole-genome sequencing identified Omicron BA.2 variant among 33 cases, which had high homology with the index cases. @*Conclusion@#This epidemic was a cluster of COVID-19 caused by imported Omicron BA.2 variant infection from Shanghai Municipality, and the COVID-19 transmission was mainly caused by indoor aerosols.

Methods for the analysis of uranium aerosol concentration in the workplace of uranium processing and fuel fabrication facilities / 中国辐射卫生

Objective To establish a method for uranium aerosol sample collection, dry ashing treatment, and laboratory laser-fluorescence measurement in the workplace of uranium processing and fuel fabrication facilities. Methods Through optimization experiments, the effects of sampling flow, sample pH value, and test temperature on uranium aerosol concentration results were studied, and the detection limit, precision, and recovery rate of the method were tested. Results Under the optimal test conditions, the detection limit of the method was 0.025 ng/mL; the minimum detectable concentration of 1 m3 of aerosol samples was 1.25 × 10−3 μg/m3; the relative standard deviation (RSD) of the measurement results was less than 5%; the recovery rate was between 96% and 104%. Conclusion The detection limit, precision, and accuracy of the method meet the testing requirements for uranium aerosol samples in the workplace of uranium processing and fuel fabrication facilities.

Maintenance of sterility in SMS packaging in dental environments: concern with biosafety

Healthcare services must be guided by biosafety practices and microbial control. This control is highly influenced by humidity, which directly impacts the maintenance of sterility of the materials used in the appointments. High concentration of moisture, in the form of aerosol, splashes and spills, is caused during dental care. During the COVID-19 times the contamination by aerosol and droplets worries greatly. Considering that it could cause harm to the sterility of an autoclaved material, especially in dental environments, the objective was to evaluate the behavior of SMS sterilization packages (Spunbonded / Meltblown / Spunbonded) against microbial penetration in an aqueous vehicle. SMS of three brands were challenged, equally divided into two groups: virgin and processed (subjected to a single autoclaving cycle). Each specimen was aseptically deposited on Macconkey agar. Subsequently, 5 µL of Escherichia coliATCC 25922 saline solution [108CFU mL-1] was deposited in center of the SMS specimen and the dish incubated at36°C/ 48h. Reading was performed by the presence or absence of bacterial growth typical of the species under the SMS, observed on the back of Petri dish. The lowest penetration rate observed was 60% for one of the brands in the virgin condition, and 75% for two brands in the processed condition. Statistical analysis showed an association between bacterial penetration and the evaluated group, this association being valid only in the virgin condition. The different SMS behave similarly in terms of resistance to bacterial penetration after being processed. The data show that moisture can assist in bacterial transport through sterilized SMS. Therefore, SMS packages are not able to prevent bacterial penetration, and possibly other microorganisms, when in aqueous vehicles, offering a potential risk of breaking the aseptic chain. Thus, care must be taken in routines for handling and storage sterile packaging.

Máscara N95 e o dilema da trajetória balística das partículas respiratórias na COVID-19 / N95 mask and the dilemma of the ballistic trajectory of respiratory particles in COVID-19 / Respiradores N95 y el dilema de la trayectoria balística de partículas respiratorias en COVID-19

Objetivo: Apresentar elementos teóricos acerca da transmissão do SARS-CoV-2 por meio das partículas respiratórias, para além do seu diâmetro aerodinâmico e trajetória balística, a subsidiar reflexões sobre a adequação do uso de máscaras pelos profissionais de saúde. Método: Ensaio acadêmico com o uso de dados de revisão narrativa da literatura. Resultados: Clarifica a confusão acerca dos termos gotículas, núcleos de gotículas, aerossóis e par-tículas, divergências que contribuem para entendimentos diferenciados sobre os mecanismos de transmissão desse agente etiológico, levando à adoção de distintas medidas de intervenção para o controle do vírus. Apresenta dados da transmissibilidade do SARS-CoV-2 pelo ar, a despeito das dificuldades técnica e metodológica para a detecção desse agente em tal meio, situação que dificulta conclusões contundentes acerca da transmissão aérea do pató-geno.Conclusão: Acredita-se ser um erro usar a falta de conclusões sobre a identificação do SARS-CoV-2 em amostras de ar para questionar a transmis-são aérea e, igualmente, para recomendar medidas de prevenção segundo o tamanho aerodinâmico dos vírus. Assim, o uso da máscara N95 por profis-sionais de saúde durante pandemia deve ser medida basilar e inequívoca para a proteção e a segurança dessa população.

Objective: To present theoretical elements about the transmission of SARS CoV-2 through respiratory particles, in addition to its aerodynamic dia-meter and ballistic trajectory, to support reflections on the adequacy of the use of masks by health professionals. Method: Academic essay using narrative review data from the literature. Results: Clarifies the confusion about the terms droplets, droplet nuclei, aerosols and particles, divergences that contribute to diffe-rentiated understandings about transmission mechanisms of this etiological agent, with the adoption of different intervention measures to control this virus. It shows data on the transmissibility of SARS-CoV-2 by air, despite the technical and methodological difficulties for detecting this agent in the air, a situation that hinders hard conclusions about the aerial transmission of this pathogen. Conclusions: It is believed to be an error to use the lack of sars-cov-2 identification conclusions in air samples, to question airborne transmission, also to recommend prevention measures depending on the aerodynamic size of viruses. Thus, the use of the N95 mask by health professionals during the pandemic should be a basic and unequivocal measure for the protection and safety of this population.

Objetivo: Presentar elementos teóricos sobre la transmisión del SARS CoV-2 a través de partículas respiratorias, además de su diámetro aerodi-námico y trayectoria balística, para apoyar reflexiones sobre la adecuación del uso de mascarillas por parte de los profesionales sanitarios. Método: Ensayo académico utilizando datos de revisión narrativa de la literatura. Resultados: Aclara la confusión sobre los términos gotitas, núcleos de gotitas, aerosoles y partículas, divergencias que contribuyen a entendimientos diferenciados sobre los mecanismos de transmisión de ese agente etiológico, con la adop-ción de diferentes medidas de intervención para controlar ese virus. Presenta datos sobre la transmisibilidad del SARS-CoV-2 por vía aérea, a pesar de las dificultades técnicas y metodológicas para detectar ese agente en el aire, situación que dificulta duras conclusiones sobre la transmisión aérea del pató-geno. Conclusión: Se cree que es un error utilizar la falta de conclusiones sobre la identificación del SARS-CoV-2 en muestras de aire para cuestionar la transmisión aérea e, igualmente, recomendar medidas de prevención según el tamaño aerodinámico de los virus. Así, el uso de los respiradores N95 por parte de los profesionales sanitarios durante la pandemia debe ser una medida básica e inequívoca para la protección y seguridad de esta población.

Radioactive concentration of 131I in the air of treatment workplaces for differentiated thyroid cancer with sodium iodide 131I oral solution / 中国辐射卫生

Objective To study the radioactive concentration of 131I in the air of workplaces where sodium iodide [131I] oral solution was administrated for patients with differentiated thyroid cancer (DTC) in the Department of Nuclear Medicine, and to estimate the internal radiation dose to the staff. Methods Workplaces of radioiodine 131I therapy for DTC patients in the Department of Nuclear Medicine of a hospital were investigated. Air samples in 131I administration areas and treatment wards were collected respectively and were measured by low-background gamma-ray spectrometry to calculate the activity concentration of 131I in the air and to further estimate the internal radiation dose to staffs. Results The activity concentration in the 131I administration area within the first 3 h of administration was 3～187 Bq/m3. During administration and within the first 3 h of administration, the staff exposed in the administration area for 5～30 min received an internal radiation dose of 0.08～0.50 μSv and 0.00～0.04 μSv, respectively. The highest activity concentration of 131I in the air of the ward was measured on the day of administration, reaching 3091 Bq/m3. After patients were discharged, the activity concentration in the ward gradually decreased to 10～242 Bq/m3 within 48 h. Within 48 h after patients were discharged, the staff exposed in the ward for 5～30 min received an internal radiation dose of 0.01～14.11 μSv. Conclusion A high activity concentration of 131I in the air was recorded during administration for DTC patients in radioiodine 131I therapy, and thus we recommend remote instructed administration or administration through a shielded window. We also recommend that non-treatment related personnel except medical staffs should not enter the ward during patients’ hospitalization at which the activity concentration of 131I in the ward was the highest. After patients were discharged, a delayed entry into the ward is recommended to reduce the internal radiation dose.

Retrospective analysis of laboratory-acquired infection in China / 中国热带医学

@#Abstract: Objective To collect the cases of laboratory-acquired infections (LAI) reported in literatures in China, summarize the infection routes and causes of LAI in China, in order to improve laboratory staff's understanding of its occupational health and safety risks. Methods　The cases of laboratory-acquired infection reported in domestic literatures were collected from PubMed, CNKI, Wanfang Database, CBM China Biomedical Literature Database up to April 11, 2022, retrospectively analyze the number and causes of LAI reports, the main risk factors of LAI and its harm to society, the consequences of LAI or the leakage of pathogenic microorganisms, and put forward the relevant countermeasures of biological safety. Results　A total of 22 LAI reports were collected, reviewed and integrated into 21 reports. There were 7 kinds of pathogenic microorganisms. The main pathogenic microorganisms were hantavirus (42.86%, n=9) and Brucella (33.33%, n=7). There were 122 cases and 3 deaths in the laboratory. Most of the reports came from research laboratories (66.67%, n=14). The main route of infection was inhalation of aerosol (42.86%, n=9), followed by transdermal route (38.09%, n=8). Conclusions Failure to report LAI events will increase the risk of pathogenic microorganisms spreading to people outside the laboratory and the environment through infected laboratory staff. Local health institutions and laboratories should be encouraged to report LAI cases as a powerful tool for monitoring accidental leakage of pathogenic microorganisms and further improving laboratory biosafety. The laboratory needs strong biosafety measures to protect staff's health and prevent environmental pollution caused by accidental leakage of pathogenic microorganisms.

Applications of optimal flow oxygen-driven aerosol inhalation of budesonide in patients with acute exacerbation of chronic obstructive pulmonary disease / 中国实用护理杂志

Objective:To investigate of optimal flow oxygen-driven aerosol inhalation of budesonide in patients with acute exacerbation of chronic obstructive pulmonary disease, to provides a reference for improving the atomization effect.Methods:Totally, ninety-six patients with acute exacerbation of chronic obstructive pulmonary disease in Guangzhou Red Cross Hospital from June 2019 to December 2020 were collected and assigned to the low flow group, middle flow group and high flow group according to the random number table method, with 32 cases in each group. All patients received oxygen-driven aerosol inhalation of budesonide therapy, the oxygen flow were 4 L/min, 6 L/min and 8 L/min in the three groups, respectively. Before and after 7 days of treatment, the indices including respiratory dynamics, pulmonary function and blood gas analysis were compared among the three groups.Results:There was no significant difference in the indices including respiratory dynamics, pulmonary function and blood gas analysis before treatment among the three groups( P>0.05). After 7 days of treatment, the peak airway pressure, plateau airway pressure, inspiratory resistance were (22.53 ± 3.83) cmH 2O(1 cmH 2O=0.098 kPa), (15.97 ± 3.01) cmH 2O, (23.25 ± 2.92) cmH 2O·L -1·s -1 in the middle flow group, lower than those in the low flow group (26.09 ± 3.04) cmH 2O, (18.13 ± 2.54) cmH 2O, (26.31 ± 3.65) cmH 2O·L -1·s -1 and high flow group (26.13 ± 3.28) cmH 2O, (17.44 ± 2.02) cmH 2O, (25.06 ± 3.56) cmH 2O·L -1·s -1, the pulmonary dynamic compliance was (33.16 ± 4.43) ml/cmH 2O in the middle flow group, higher than that in the low flow group and high flow group (29.84 ± 3.73), (30.47 ± 3.53) ml/cmH 2O, the differences were statistically significant ( F values were 5.96-11.82, all P<0.05). The FEV 1, FEV 1/FVC, ratio of FEV 1 to estimated vital capacity were (1.36 ± 0.26) L, (49.91 ± 5.94)%, (44.81 ± 5.53)% in the middle flow group, higher than those in the low flow group and high flow group (1.23 ± 0.19) L, (45.22 ± 6.56)%, (40.88 ± 5.97)% and (1.20 ± 0.18) L, (46.41 ± 5.30)%, (41.78 ± 6.32)%, the differences were statistically significant ( F=4.91, 5.36, 3.84, all P<0.05). The PaO 2, oxygenation index were (73.06 ± 7.24), (176.18 ± 17.62) mmHg(1 mmHg=0.133 kPa) in the middle flow group, higher than those in the low flow group and high flow group (67.16 ± 5.10), (164.54 ± 12.34) mmHg and (69.44 ± 7.10), (167.07 ± 16.24) mmHg, PaCO 2 was (52.75 ± 6.22) mmHg in the middle flow group, lower than that in the low flow group and high flow group(57.97 ± 6.75), (56.31 ± 6.45) mmHg, the differences were statistically significant ( F=6.61, 4.96, 5.42, all P<0.05). Conclusions:Oxygen-driven aerosol inhalation of budesonide for acute exacerbation of chronic obstructive pulmonary disease patients, oxygen flow are 6 L/min can effectively improve the indices of respiratory dynamics and blood gas analysis as well as improve pulmonary function.

Optimization of preparation technology of baicalin lipid nano foam aerosol / 中国药房

OBJECTIVE To optimize the pr eparation technology of the baicalin lipid nano foam aerosol （BC-LN-FA）. METHODS Baicalin lipid nanoparticle （BC-LN）and BC-LN-FA were prepared by the thin film dispersion method and homogeneous emulsification method ，respectively，using baicalin （BC） as the model drug. The preparation technology was optimized by Box-Behnken design-response surface methodology using particle size and encapsulation efficiency （EE）as indexes ，with dosage ， emulsifier dosage ，co-emulsifier dosage and homogenization time as factors. The morphology ，particle size ，polymerdispersity index（PDI），EE，the viscosity ，the foam dissolution rate and in vitro transdermal release of BC-LN-FA were characterized. RESULTS The optimal technology included 25 mg BC ，40 mg emulsifier （mass ratio of stearic acid-soybean lecithin-glycerol was 1∶1∶1），30 mg co-emulsifier （mass ratio of octadecanol-lactic acid was 1∶1），homogenization time of 20 min. Results of 3 times of validation tests showed that particle size of prepared BC-LN-FA was （151.70±2.40）nm，EE was （68.62±1.16）％；the deviation of them from the predicted value （particle size of 150.80 nm，EE of 67.02％）were 0.60％ and 2.39％ respectively. The BC-LN-FA prepared by the optimal process was light yellow opalescence ，uniform in particle size and round-like in shape. The viscosity，the foam dissolution rate ，the content of BC and PDI were （122.92±5.09）mPa·s，（65.32±3.22）％，（7.01±0.12）％ and（0.199±0.006），respectively. At 48 h，the cumulative release rates of BC-LN-FA in phosphate buffer saline （PBS）at pH 7.4， 6.8，5.0 were（54.12±2.69）％，（57.85±4.25）％ and（59.47±1.83）％，respectively；those of free BC in PBS at pH 7.4 was only （15.04±1.43）％. CONCLUSIONS The optimized technology is stable and feasible. Prepared BC-LN-FA has a uniform particle size，high digestion rate and certain viscosity.

Electronic Cigarette Vapour and the Impacts on Oral Health: A Review

ABSTRACT@#Electronic cigarettes (e-cigarettes) have been in demand among young generations as a modern way of smoking since last decade. E-cigarette devices generate the vapour through the heating process and the inhalation of vapour through the mouth which is known as vaping directly exposed the oral cavity to potentially toxic chemicals in the vapour. The e-cigarette vapour has been reported with potential systemic and oral health impacts though it is to a lesser extent than the conventional cigarette. The toxicity of the chemicals in e-cigarette vapour has been highlighted by various in-vitro studies and currently being explored by many researchers. Nicotine content in e-cigarette vapour not only causes addiction but has deleterious effects on the oral mucosa. E-cigarette vapour is commonly associated with oral health-related problems such as irritation to the oral mucosa, periodontal disease, and possibly the initiation of dental caries. As a marketing strategy, e-cigarette has been promoted as a safer way of smoking habit and use as a smoking cessation tools. Non-scientific assertions regarding e-cigarettes are causing public misunderstanding, leading people to assume that they are safe while the truth is yet unclear. This narrative review aims to emphasise the hazard of e-cigarette vapour and the outcome to oral health by summarising the evidence gathered from previous studies and the potential role of e-cigarette for smoking cessation aids considering the widespread usage of e-cigarettes and public concerns.