Objective To make an assessment method for the efficiency of spraying air cleaning products used in the indoor air. Methods 1.5 m3 chamber was used, the temperature was (21?2.5) ℃ and the relative humidity was (40?5)%. The formaldehyde of 10 times of the standard limit was added in the chamber, then the products were sprayed, the air cleaning efficiency was assessed at different times. Results The polluted indoor air by formaldehyde could be purified by air the cleaning products, the CADRq≥2.0?10-2 m3/(min?g) within 60 min. Conclusion The assessment method is accurate and applicable to the assessment of efficiency of spraying air cleaning products used in the indoor air cleaning.

Objective To observe the ultrastructural change of intestinal mucosa in mice infected with Blastocystis hominis, and to study the pathogenic mechanism of B.hominis infection. Methods 20 Kunming mice were randomly divided into 4 groups: group A treated with immunosuppressant (dexamethasone), group B without immunosuppressant, group C as normal control and group D as immunosuppressant control. Groups A and B were then orally infected with 204 cysts of B. hominis. Groups C and D were treated as control by infusing same volume of Locke′s solution. Six days after inoculation, mice in each group were killed and mucosa of ileocecum was observed by transmission electron microscope (TEM) and scanning electron microscope (SEM). Results Under SEM, B. hominis located in enteric cavity and on the surface of ileocecum mucosa. Individual parasites also invaded into mucosa and its fold. Partial destruction of microvilli on the mucosa was observed. TEM observation indicated a reduction of microvilli on the surface of absorptive cells. Mitochondrial edema, rough endoplasmic reticulum dilatation and degranulation were found on absorptive cells and goblet cells. Lymphocyte infiltration and eosinophilia were found in intercellular stroma. Pathological changes in group A were more serious than that of group B. No abnormal change on the mucosal ultrastructure was found in groups C and D. Conclusions B. hominis infection causes significant ultrastructural lesion on the ileocecal mucosa in mice. Immune status of the mice can affect the degree of the lesion due to infection.

Objective To investigate the epidemiological and clinical characteristics, risk factors, outcome and prevention strategy of very low birth weight infant (VLBWI) with nosocomial infection in neonatal intensive care unit (NICU). Methods The VLBWIs whose birth weight were less than 1500 g and hospital stays were more than 48 hours in NICU of Peking University Third Hospital from January 1, 1998 to December 31, 2008 were selected in this study. They were divided into nosocomial infection group and non-infection group. The clinical features and outcomes of nosocomial infection were summarized and the risk factors of which were analyzed with Logistic regression. Results There were 158 VLBWIs who fit for the criteria of our study during the eleven years, the mean birth weight was (1263.8± 155.5) g and the mean gestational age was (30.4±2.1) weeks. There were 70 times and 56 cases suffered from nosocomial infections. The incidence of nosocomial infection was 35.4% and hospital stay-related incidence was 14.4‰. Among 70 times of infections, there were 40(57.1%) pneumonia, 22(31.4%) septicemia, 4(5.8%) thrush, 1(1.4%)conjunctivitis, 1 ( 1.4%) upper respiratory tract infection and 2 (2.9%) unknown site infections.Forty-one strains of bacteria were isolated from 121 specimens, among which gram-negative bacillus accounted for 56.1% and gram-positive cocci for 46.3%. The duration of hospital stay of VLBWIs with nosocomial infection was significantly longer than that without [(43.7±15.5) d vs (26.3±14.4) d] (t = -7.058, P＜0.01). The fatality rate of VLBWIs with and without nosocomial infection was 3.6% (2/56) and 3.9% (4/102), and there was no significant difference (x2 = 0.012,P＞0.05). Logistic regression showed that mechanical ventilation (OR = 3.388, 95% CI: 1.656-6.932, P=0.001) and parenteral nutrition (OR= 7.054, 95%CI: 2.005-24.813, P=0.002) were risk factors of nosocomial infection. Conclusions The incidence of nosocomial infection in VLBWIs in NICU is high. Mechanical ventilation and parenteral nutrition should be avoided and the duration of invasive operation and treatment should be shortened as much as possible to minimize the chances of nosocomial infection in VLBWIs.

Objective: To compare diary-reported trips and Global Positioning System (GPS) recording trips and identify the reasons for the discrepancies between two methods. Methods: The survey was conducted in Jiangning district in Nanjing city during July to September and November to December, 2015. Both the diary records and GPS method were used to investigate the travel behavior of 33 retired adults for 5 consecutive days. The GPS traces were display in Google Earth and then split into trips to compare with the diary records according to time and location. χ² test was used to analyze the influence of trip characteristics on misreporting rates of each method. Results: A total of 1 087 trips in the survey can be compared between the diary (n=909) and the GPS method (n=912). 7.3% (79/1 087) of the trips were only recorded by GPS method, and 11.8% (128/1 087) were only reported in the diary. Of the remaining 880 trips recorded by the both methods, 86.7% (763/880) matched each other, while 13.3% (117/880) did not. For the matched trips, the difference between the trip durations recorded by diary and GPS method was 2.0 (quartile was 6.0) minutes and the diary method overestimated about 25.0% trip durations when compared with the GPS method. The accuracy rates were 84.8%(903/1 065) and 86.9%(925/1 065) for diary and GPS method, respectively. Both methods were more likely to misreport the trip under 5 minutes. The misreporting rates of diary method for trips under 5 minutes were 6.8 times higher than trips over 30 minutes (21.7% vs 3.2%). The reporting accuracy was also significantly different among trips by different travel mode (P<0.05) for both methods, diary method had the lowest accuracy in reporting vehicles recorders (69.3%, 133/192), while GPS method was more accuracy in both biking (91.9%, 136/148) and vehicles recorders(89.6%, 172/192). The main reasons for misreporting by diary method were forgetting or unwilling to record and failing to record trips according to travel mode, while forgetting to carry GPS device, bad GPS signal and failing to locate the position were the main reasons for misreporting by GPS method. Conclusion The majority of the trips reported in diary and GPS method are well consistent with each other. Both of the methods should be used simultaneously in the survey of time-activity pattern to improve the data quality.

Objective: To explore the effect of ambient fine particulate matters (PM_2.5) exposure on nasal oxidative stress level in patients with allergic rhinitis (AR). Methods: A panel of sixty AR patients was recruited as subjects. Four repeated measurements were carried out from June 2017 to January 2018. Nasal irrigation solution was collected and examined for malondialdehyde (MDA) and superoxide dismutase (SOD). Monitoring data of atmospheric pollutants and meteorological factors during measurement periods were also collected. Time activity pattern combined with micro-environment monitoring method was used to evaluate PM_2.5 exposure. Mixed effect model was applied to analyze the relationship between PM_2.5 exposure concentration and oxidative stress level. Results: 49 subjects accomplished the four repeated measurements, and the mean±SD of their age was (36.7±8.4) years old. The median of MDA and SOD in four measurement periods was 3.70, 3.70, 5.58, 6.24 nmol/ml, and 105.50, 102.50, 95.00, 96.50 U/ml. The concentration of PM_2.5 exposure in four measurement periods was (40.0±2.7), (41.5±2.5), (52.3±5.9) and (74.7±4.9) μg/m³, respectively. Results of single pollutant mixed effect model analysis showed that 0-, 1-, 2-, 3-day lag concentrations of PM_2.5 was significantly positively associated with MDA, about β (95%CI) estimated as 0.24 (0.17, 0.30), 0.34 (0.27, 0.41), 0.32 (0.20, 0.44) and 0.33 (0.23, 0.43), respectively. 0-, 1-, 2-day concentrations of PM_2.5 was significantly negatively associated with SOD, about β (95%CI) estimated as -0.99 (-1.66, -0.31), -1.35 (-2.08, -0.62) and -0.94 (-1.80, -0.07), respectively. Multivariate analysis found that lag 1-day concentration of PM_2.5 was still significantly associated with MDA and SOD after controlling for temperature, age and other influencing factors. For a 10 μg/m³ increase of PM_2.5 concentration, MDA increased 0.26 (95%CI: 0.18, 0.33) nmol/ml, and SOD decreased 0.87 (95%CI: 0.21, 1.53) U/ml. Conclusion Our results suggested that PM_2.5 exposure can aggravate the nasal oxidative stress response of AR patients.