[Spatial and Temporal Distribution Characteristics of Ozone Concentration and Health Benefit Assessment in the Beijing-Tianjin-Hebei Region from 2015 to 2020]

To evaluate the spatial and temporal distribution characteristics of ambient ozone (O3) in the Beijing-Tianjin-Hebei (BTH) Region, the land use regression (LUR) model and random forest (RF) model were used to simulate the ambient O3 concentration from 2015 to 2020. Meanwhile, all-cause, cardiovascular, and respiratory mortalities as well as economic losses attributed to O3 were also estimated. The results showed that upward trends with fluctuation were observed for ambient O3 concentration, mortalities, and economic losses attributable to O3 exposure in the BTH Region from 2015 to 2020. The areas with high O3 concentration and great changes were concentrated in the central and southwestern regions, whereas the concentration in the northern region was low, and the change degree was small. The spatial distribution of the mortalities was also consistent with the spatial distribution of O3 concentration. From 2015 to 2020, the economic losses regarding all-cause mortality and cardiovascular mortality increased in 13 cities of the BTH Region, whereas the economic losses of respiratory mortality decreased in 4 cities in the BTH Region. The results indicated that the priority areas for O3 control were not uniform. Specifically, Beijing, Tianjin, Hengshui, and Xingtai were vital areas for O3 pollution control in the BTH Region. Differentiated control measures should be adopted based on the characteristics of these target areas to decline O3 concentration and reduce health impacts and economic losses associated with O3 exposure.

Evaluating the performance and influencing factors of three portable black carbon monitors for field measurement

Black carbon (BC) is associated with adverse human health and climate change. Mapping BC spatial distribution imperatively requires low-cost and portable devices. Several portable BC monitors are commercially available, but their accuracy and reliability are not always satisfactory during continuous field observation. This study evaluated three models of portable black carbon monitors, C12, MA350 and DST, and investigates the factors that affect their performance. The monitors were tested in urban Beijing, where portable devices running for one month alongside a regular-size reference aethalometer AE33. The study considers several factors that could influence the monitors' performance, including ambient weather, aerosol composition, loading artifacts, and built-in algorithms. The results show that MA350 and DST present considerable discrepancies to the reference instrument, mainly occurring at lower concentrations (0-500 ng/m3) and higher concentrations (2500-8000 ng/m3), respectively. These discrepancies were likely caused by the anomalous noise of MA350 and the loading artifacts of DST. The study also suggests that the ambient environment has limited influence on the monitors' performance, but loading artifacts and accompanying compensation algorithms can result in unrealistic data. Based on the evaluation, the study suggests that C12 is the best choice for unsupervised field measurement, DST should be used in scenarios where frequent maintenance is available, and MA350 is suitable for research purposes with post-processing applicable. The study highlights the importance of assigning portable BC monitors to appropriate applications and the need for optimized real-time compensation algorithms.

Evolution of Ozone Formation Sensitivity during a Persistent Regional Ozone Episode in Northeastern China and Its Implication for a Control Strategy

In recent years, the magnitude and frequency of regional ozone (O3) episodes have increased in China. We combined ground-based measurements, observation-based model (OBM), and the Weather Research and Forecasting and Community Multiscale Air Quality (WRF-CMAQ) model to analyze a typical persistent O3 episode that occurred across 88 cities in northeastern China during June 19-30, 2021. The meteorological conditions, particularly the wind convergence centers, played crucial roles in the evolution of O3 pollution. Daily analysis of the O3 formation sensitivity showed that O3 formation was in the volatile organic compound (VOC)-limited or transitional regime at the onset of the pollution episode in 92% of the cities. Conversely, it tended to be or eventually became a NOx-limited regime as the episode progressed in the most polluted cities. Based on the emission-reduction scenario simulations, mitigation of the regional O3 pollution was found to be most effective through a phased control strategy, namely, reduction of a high ratio of VOCs to NOx at the onset of the pollution and lower ratio during evolution of the O3 episode. This study presents a new possibility for regional O3 pollution abatement in China based on a reasonable combination of OBM and the WRF-CMAQ model.

[Clinical analysis of 226 cases of deviated nose with deviated nasal septum treated by endoscopic assisted functional rhinoplasty]

Objective: To explore the method and effect of endoscopic assisted functional rhinoplasty for patients with deviated nose and deviated nasal septum, which achieve correction of nasal morphology and ventilation dysfunction. Methods: The clinical data of 226 patients with deviated nose and deviated nasal septum from June 2009 to February 2022 who were treated by endoscopic assisted functional rhinoplasty in the Affiliated Hospital of Qingdao University were analyzed retrospectively. There were 174 males and 52 females, with the age ranging from 7 to 67 years old. The effect was evaluated by subjective and objective evaluation methods. SPSS 27.0 software was used for statistical analysis. Results: All patients were followed up for 6 to 24 months, 174 cases were cured (174/226, 76.99%), 52 cases were effective (52/226, 23.01%), and the total effective rate was 100% (226/226). The difference between preoperative and postoperative facial appearance deviation was statistically significant ((6.84±2.25)mm vs (1.82±1.05)mm, t=38.94, P<0.001), and the nasal ventilation function of all patients was improved. Conclusions: Endoscopic assisted functional rhinoplasty for the patients with deviated nose combined with deviated nasal septum has the advantages of clear surgical field, fewer complications, and good result. It can achieve the purpose of simultaneous correction of nasal and ventilation dysfunction, which is recommended for popularizing in clinical application.

Dramatic changes in aerosol composition during the 2016-2020 heating seasons in Beijing-Tianjin-Hebei region and its surrounding areas: The role of primary pollutants and secondary aerosol formation

With the implementation of a series of air pollution mitigation strategies during the past decade, great air quality improvements have been observed in the BTH region. Despite of significant decreases in gaseous pollutants, such as SO₂ and NO₂, the enhancement of secondary aerosol formation was observed. NO₃^- has surpassed SO₄^2- and OM to become the dominant PM_2.5 component. We find that the reduction of POC mainly dominated the decreasing trend of OC. As for secondary inorganic components, the key processes or factors controlling the spatial-temporal variation characteristics were different. The areas with large SO₄^2- concentrations corresponded well to those with high SO₂ concentrations, while the synchronized NO₃^- better followed spatial patterns in O₃ than NO₂. From 2016 to 2020, the response of SO₄^2- to SO₂ was close to a linear function, while the reaction of NO₃^- to the decrease of NO₂ displayed nonlinear behavior. Such different relationships indicated that SO₄^2- was predominantly controlled by SO₂, while NO₃^- was not only related to NO₂ but also determined by the secondary conversion process. The ratios of SO₄^2-, NO₃^-, NH₄⁺, and OC to EC between 2016 and 2020 were generally higher than 1 in typical BTH cities, and the ratio of NO₃^- to EC was exceptionally high, with a range reaching up to 200 %. Besides, this ratio coincided well with the enhancement of O_x, indicating the potential role of O_x to secondary NO₃^- formation. The diurnal cycle of NO₃^-, O₃, and NO₂ concentration change rate indicated that the relative increase of O₃ during nighttime may offset the effectiveness of NO_X emission reduction. This study provided observational evidence of enhanced secondary NO₃^- formation with the rising trend of atmospheric oxidation and emphasized the importance of nighttime chemistry for NO₃^- formation in the BTH region.

Decade-long trends in chemical component properties of PM2.5 in Beijing, China (2011-2020)

A 10-year-long measurement of water-soluble inorganic ions in PM_2.5 was made in Beijing from June 2011 to December 2020, to investigate the interannual trends of chemical characteristics of PM_2.5 and to provide insights into the future prevention and control of PM_2.5 pollution. From 2011 to 2020, with the implementation of strict air pollution control strategies, significant changes of PM_2.5 have been observed in Beijing, with NO₃^-, SO₄^2- and NH₄⁺ decreasing at rates of 5.10, 8.80 and 7.64% yr^-1 respectively. The percentages of NO₃^- and SO₄^2- under elevated pollution levels were investigated. When PM_2.5 values fell in the range of 0-400 μg m^-3, NO₃^-/ SO₄^2- values were mostly higher than 1 and showed upward trends from 2011 to 2020. However, under extremely heavy haze conditions, SO₄^2- dominated PM_2.5 formation. This result was closely related to the change characteristics of the oxidation ratio of sulfate (SOR), the oxidation ratio of nitrate (NOR) and gaseous precursors under different pollution levels. The change characteristics of NOR and SOR under elevated PM_2.5 levels indicated that the aqueous phase oxidation was the key process driving SO₄^2- formation; while as for NO₃^-, in addition to the availability of NH₄⁺, the atmospheric oxidation capacity made crucial roles. The analysis of typical haze episodes during the past decade indicated that the emission reduction of gaseous pollutants, especially SO₂, made great contributions to the improved PM_2.5 air quality in Beijing. We highlighted that future efforts should focus on enhanced reduction of NO₂ emission and control of atmospheric oxidation capacity to further reduce particulate nitrate formation.

LncRNA MALAT1 induced by hyperglycemia promotes microvascular endothelial cell apoptosis through activation of the miR-7641/TPR axis to exacerbate neurologic damage caused by cerebral small vessel disease

Background

This study aimed to explore the effect of hyperglycemia-induced long noncoding RNA (lncRNA) metastasis-associated lung carcinoma transcript 1 (MALAT1) on microvascular endothelial cell activity. In addition, we investigated the possible downstream molecular regulatory mechanism in order to provide an adjunctive therapeutic target for the prognostic nerve recovery of cerebral small vessel disease (CSVD).

Methods

A rat model of diabetes was induced by streptozotocin (STZ) injection in combination with a high-energy diet. The mixed model of CSVD and hyperglycemia was prepared by injection of homologous microemboli in vitro. Results of 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay and enzyme-linked immunosorbent assay (ELISA) showed that the inhibition of lncRNA MALAT1 by siRNA in a high-glucose environment effectively alleviated the cell damage caused by high glucose (HG) and reduced the rate of apoptosis. We found that the upregulation of downstream miR-7641 and TPR (translocated promoter region) reduced the occurrence of cell damage and apoptosis.

Results

The results of neurological deficit score showed that the scores of ICH group, HG group and HG + ICH group were significantly higher than those of Sham group, and the differences were statistically significant. The qPCR results showed that the MALAT1 level of the model group was significantly different from that of the sham group, and the expression levels of damage markers vWF and ICAM-1 were detected by Western blot (WB), which were significantly higher in the model group than in the sham group. The MTT cell activity assay showed that the addition of miR-7641 inhibitor or TPR short hairpin RNA (shRNA) into normally cultured cells reduced cell activity. ELISA results showed that low expression of miR-7641 increased the apoptosis rate of microvascular endothelial cells. Western blot (WB) results showed that the protein expression levels of BAX and cleaved caspase-3 (c-caspase-3) were negatively correlated with miR-7641. The regulation of TPR expression showed similar results.

Conclusions

High blood glucose level induced the increase of lncRNA MALAT1 and regulated the expression of TPR by activating miR-7641 to promote the initiation of apoptosis of microvascular endothelial cells, aggravating the neurological dysfunction caused by CSVD.

Enhanced secondary pollution offset reduction of primary emissions during COVID-19 lockdown in China

To control the spread of the 2019 novel coronavirus (COVID-19), China imposed nationwide restrictions on the movement of its population (lockdown) after the Chinese New Year of 2020, leading to large reductions in economic activities and associated emissions. Despite such large decreases in primary pollution, there were nonetheless several periods of heavy haze pollution in eastern China, raising questions about the well-established relationship between human activities and air quality. Here, using comprehensive measurements and modeling, we show that the haze during the COVID lockdown was driven by enhancements of secondary pollution. In particular, large decreases in NO_x emissions from transportation increased ozone and nighttime NO₃ radical formation, and these increases in atmospheric oxidizing capacity in turn facilitated the formation of secondary particulate matter. Our results, afforded by the tragic natural experiment of the COVID-19 pandemic, indicate that haze mitigation depends upon a coordinated and balanced strategy for controlling multiple pollutants.

Cause of PM2.5 pollution during the 2016-2017 heating season in Beijing, Tianjin, and Langfang, China

To investigate the cause of fine particulate matter (particles with an aerodynamic diameter less than 2.5 µm, PM_2.5) pollution in the heating season in the North China Plain (specifically Beijing, Tianjin, and Langfang), water-soluble ions and carbonaceous components in PM_2.5 were simultaneously measured by online instruments with 1-hr resolution, from November 15, 2016 to March 15, 2017. The results showed extreme severity of PM_2.5 pollution on a regional scale. Secondary inorganic ions (SNA, i.e., NO₃^-+SO₄²+ NH₄⁺) dominated the water-soluble ions, accounting for 30%-40% of PM_2.5, while the total carbon (TC, i.e., OC + EC) contributed to 26.5%-30.1% of PM_2.5 in the three cities. SNA were mainly responsible for the increasing PM_2.5 pollution compared with organic matter (OM). NO₃^- was the most abundant species among water-soluble ions, but SO₄^2- played a much more important role in driving the elevated PM_2.5 concentrations. The relative humidity (RH) and its precursor SO₂ were the key factors affecting the formation of sulfate. Homogeneous reactions dominated the formation of nitrate which was mainly limited by HNO₃ in ammonia-rich conditions. Secondary formation and regional transport from the heavily polluted region promoted the growth of PM_2.5 concentrations in the formation stage of PM_2.5 pollution in Beijing and Langfang. Regional transport or local emissions, along with secondary formation, made great contributions to the PM_2.5 pollution in the evolution stage of PM_2.5 pollution in Beijing and Langfang. The favourable meteorological conditions and regional transport from a relatively clean region both favored the diffusion of pollutants in all three cities.

Enhanced secondary pollution offset reduction of primary emissions during COVID-19 lockdown in China

To control the spread of the 2019 novel coronavirus (COVID-19), China imposed nationwide restrictions on the movement of its population (lockdown) after the Chinese New Year of 2020, leading to large reductions in economic activities and associated emissions. Despite such large decreases in primary pollution, there were nonetheless several periods of heavy haze pollution in eastern China, raising questions about the well-established relationship between human activities and air quality. Here, using comprehensive measurements and modeling, we show that the haze during the COVID lockdown was driven by enhancements of secondary pollution. In particular, large decreases in NO_x emissions from transportation increased ozone and nighttime NO₃ radical formation, and these increases in atmospheric oxidizing capacity in turn facilitated the formation of secondary particulate matter. Our results, afforded by the tragic natural experiment of the COVID-19 pandemic, indicate that haze mitigation depends upon a coordinated and balanced strategy for controlling multiple pollutants.

[Chemical Composition Characteristics and Source Apportionment of PM2.5 During the Heating Period of 2016-2017 in the Eastern Part of the North China Plain]

To study the composition characteristics and source apportionment of PM_2.5 in the eastern part of the North China Plain, manual samples during the two-year heating period of 2016 and 2017 were collected in seven cities, including Hengshui, Cangzhou, Ji'nan, Dezhou, Binzhou, Zibo, and Liaocheng. The results showed that the average values of ρ(PM_2.5) during the observation periods were 137.23 μg·m^-3 and 111.83 μg·m^-3, respectively, which exceeded the daily average secondary standard limit of GB 3095-2012 "Environmental Air Quality Standard" by 1.8 and 1.5 times, respectively. The mean mass of water-soluble ions accounted for 53.32% and 47.04% of ρ(PM_2.5), respectively, of which SNA (NO₃^-, SO₄^2-, and NH₄⁺) were the main ions. During the 2016 and 2017 observation periods, NO₃^-/SO₄^2- increased from 1.35 to 1.60, while the concentration of Cl^- decreased, indicating a decrease in the impact of coal burning. The proportions of secondary organic carbon (SOC) in organic carbon (OC) were 71.63% and 55.35%, respectively, indicating the source of secondary organic carbon had decreased. Analysis of characteristic elements Fe/Al and Ba/Ni showed that dust sources and vehicle sources had increased significantly. The backward trajectories of air mass results showed that the polluted air mass mainly came from the northwest direction during the observation period. However, the PM_2.5 concentration was highest when the air mass came from the Anhui and Jiangsu provinces.

Physical-Chemical Composition and Quality Related Changes in "Ruaner" Pear (Pyrus ussuriensis) During Freezing-Thawing Period

“Ruaner” pear (Pyrus ussuriensis Maxim.) is a fruit crop that is frequently served frozen in China. It is a typical postharvest ripening fruit that needs to ripen after harvest before it can be eaten, and freezing–thawing is one way that pears are treated during postharvest ripening. In order to study the physical–chemical composition and quality-related changes in “Ruaner” pears that result the freezing–thawing period, “Ruaner” pears were kept in a freezer (−20 °C) for 7 days, after which they were transferred to room temperature for thawing. The color of the peel of the “Ruaner” pears changed from yellow-green to yellow and then brown. The chlorophyll content and titratable acidity (TA) decreased significantly throughout 0–12 h period. The carotenoid content tended to rise and then decrease, peaking at 3 h after thawing (HAT), while the soluble solids content (SSC), firmness, total phenolic content, and total flavonoid content all generally decreased. The composition of soluble sugars and organic acids was examined in “Ruaner” pears, and the major soluble sugars were fructose and glucose, with citric acid being the most abundant organic acid. The data suggest that freezing–thawing significantly changes firmness, water content, SSC, and TA in “Ruaner” pears. At 3–4 HAT, “Ruaner” pears have moderate hardness, high water content, low acid content, and higher total phenolic, total flavonoid, and soluble solids content. Therefore, 3–4 HAT is the best time for pears in terms of both table and processing quality.

Molecular Identification of Diphyllobothrium nihonkaiense from 3 Human Cases in Heilongjiang Province with a Brief Literature Review in China

Human diphyllobothriasis is a widespread fish-borne zoonosis caused by the infection with broad tapeworms belonging to the genus Diphyllobothrium. In mainland China, so far 20 human cases of Diphyllobothrium infections have been reported, and the etiologic species were identified as D. latum and D. nihonkaiense based on morphological characteristics or molecular analysis. In the present study, proglottids of diphyllobothriid tapeworms from 3 human cases that occurred in Heilongjiang Province, China were identified as D. nihonkaiense by sequencing mitochondrial cytochrome c oxidase subunit I (cox1) and NADH dehydrogenase subunit 5 (nad5) genes. Two different cox1 gene sequences were obtained. One sequence showed 100% homology with those from humans in Japan. The remaining cox1 gene sequence and 2 different nad5 gene sequences obtained were not described previously, and might reflect endemic genetic characterizations. D. nihonkaiense might also be a major causative species of human diphyllobothriasis in China. Meanwhile, the finding of the first pediatric case of D. nihonkaiense infection in China suggests that infants infected with D. nihonkaiense should not be ignored.

[Definition and Control Indicators of Volatile Organic Compounds in China]

Volatile organic compounds (VOCs) are the most complex of a wide range of pollutants that harms human health and ecological environment. However, various countries around the world differ on its definition and control indicators. Its definition, control indicators and monitoring methods of our country and local standards were also different. Based on detailed analysis of the definitions and control indicators of VOCs, the recommendations were proposed: the definition of VOCs should be different according to the different concerns between "air quality management" and "pollution emissions management"; base on different control way from production source, technological process, terminal emission, total discharge control, the control indicators system consists of 10 indicators; to formulate industry VOCs emissions standards, the most effective control way and indicators should be chosen according to characteristics of production process, way of VOCs emissions and possible control measures, etc.

Metabolic syndrome is an independent prognostic factor for endometrial adenocarcinoma

OBJECTIVE

To study the association between metabolic syndrome (MS) and the prognosis of patients with endometrial adenocarcinoma.

METHODS

A total of 385 patients with endometrial adenocarcinoma in the Department of Gynecologic Oncology, at the Zhejiang Cancer Hospital in China, between January 2001 and December 2008 were chosen. The deadline for the completion of follow-up was December 2013. The overall survival (OS) of the patients with MS was analyzed by the Kaplan-Meier method. Various clinical characteristics (e.g., clinical and surgical stage, vascular invasion, histological grade, tumor size, age at start of the first treatment, and lymphatic metastasis) related to the prognosis of endometrial adenocarcinoma were also evaluated.

RESULTS

A univariate analysis demonstrated that the OS rate of the patients with endometrial adenocarcinoma with MS was significantly worse than that of the patients without MS for all 385 patients (P = 0.001). Multivariate Cox proportional hazards regression analyses showed that stage (P = 0.001), lymphatic metastasis (P = 0.021), and MS (P = 0.049) were independent prognostic factors for endometrial adenocarcinoma. Furthermore, statistical analyses demonstrated that MS was closely related to stage (P = 0.021), grade (P = 0.022), vascular invasion (P = 0.044), tumor size (P = 0.035), and lymphatic metastasis (P = 0.014) but not with age at start of the first treatment (P = 0.188). Finally, according to the univariate analysis of the OS rate of 129 cases of endometrial adenocarcinoma with MS, stage (P = 0.001), vascular invasion (P = 0.049), tumor size >2 cm (P = 0.028), lymphatic metastasis (P = 0.002), and CA19-9 value >37 U/m (P = 0.002) all showed significantly low P values for OS.

CONCLUSION

Metabolic syndrome is an independent prognostic factor for endometrial adenocarcinoma.

[Revision process and thinking of emission standard of air pollutants for cement industry]

The new National Emission Standard of Air Pollutants for Cement Industry (GB 4915-2013) was released recently, which is the third revision since the first release in 1985. This paper reviewed the revision process for the emission standard of air pollutants in cement industry, analyzed the impact of environmental protection situation and management policies changes on the content and form of the standard. The standard formulating principles and several key issues together constitute the base of emission standard, which are not only important to complete the theories and methods of emission standard development, but also important to improve the environmental management and pollution control level.

[A comparative study on domestic and foreign emission standards of air pollutants for cement industry]

The new National Emission Standard of Air Pollutants for Cement Industry (GB 4915-2013) becomes effective on Mar. 1st, 2014. It will play an important role in pollution prevention, total emission reduction, structure adjustment, and layout optimization for cement industry. Based on the research of emission standard in China, U. S., EU and Japan, the similarities and differences in the pollutant projects, control indicators, limits and means of implementation were discussed and advice was proposed, with the purpose to provide a reference for revision of emission standard, and to improve the level of environmental management and pollution control.

Ownership governance, institutional pressures and circular economy accounting information disclosure

Purpose

– This paper aims to explore the determinants of circular economy accounting information disclosure quality, and also to make empirical analysis on the relationship between circular economy accounting information disclosure quality and corporate ownership governance and institutional pressures according to institutional theory and corporate governance theory. Finally, this paper provides some corresponding suggestions for heightening circular economy accounting information disclosure quality.

Design/methodology/approach

– This paper constructs enterprise circular economy accounting information disclosure model with Chinese characteristics. First, it takes disclosure index method to measure enterprise circular economy accounting information disclosure quality, followed by the hypotheses of this study. Then, this study employs a statistical analysis technique to empirically study the relationship between enterprise circular economy accounting information disclosure quality and ownership governance and institutional pressures, to study the ways to heighten enterprise circular economy accounting information disclosure quality in Chinese background.

Findings

– Ownership governance and institutional pressures mainly determine quality of circular economy accounting information disclosure. This paper draws the following conclusions: Chinese listed companies have heightened their circular economy accounting information disclosure quality due to ownership concentration, shareholding of institutional investors, mandatory disclosure, capital structure and assets size. However, the circular economy accounting information disclosure quality has low correlation with the profitability and the location of listed companies.

Originality/value

– Both in China and the West, few scholars or experts adopt empirical research to study the determinants of circular economy accounting information disclosure quality in an institutional theory and corporate governance theory perspective based on China’s supervisory system background. This paper makes a thorough analysis of the factors that affect listed companies’ circular economy accounting information disclosure quality, and provides some corresponding suggestions relevant for heightening circular economy accounting information disclosure quality.

Urinary perchlorate exposure and risk in women of reproductive age in a fireworks production area of China

Perchlorate is used widely in fireworks, and, if ingested, it has the potential to disrupt thyroid function. The concentrations of perchlorate in water and soil samples and in urine samples of women of reproductive age from Liuyang, the largest fireworks production area in China, were investigated. The results showed that the average perchlorate concentrations in groundwater, surface water, farmland soil, and urine samples of women from the fireworks production area were significantly greater than those from the control area. The health risk of perchlorate ingested through drinking water was assessed based on the mode recommended by the United States Environmental Protection Agency. The values of hazard quotient of river water and groundwater in the fireworks production area were much greater than the safe level (=1), which indicates that adverse health effects may result from perchlorate when these sources of water are used as drinking water. These results indicated that the environment of the fireworks production area has been polluted by perchlorate and that residents were and are facing greater exposure doses of perchlorate. Fireworks production enterprises may be a major source of perchlorate contamination.

[Effects of adenovirus-mediated p16 and p53 genes transfer on apoptosis and cell cycle of lung carcinoma cells]

OBJECTIVE

To explore the synergistic inhibition effect and apoptosis induction of p16 and p53 genes on lung carcinoma cells.

METHODS

E1-deficient and replication-defective recombinant p16 and p53 adenoviruses were generated by liposome-mediated co-transfection of recombinant plasmid pAdCMV-p16 or pAdCMV-p53 along with pJM17 and homologous recombination in 293 packaging cell. The lung cancer cell line H358, which had a homozygous deletion of p53 gene and no expression of p16 mRNA and protein, was infected with recombinant p16 and p53 adenovirus either individually or together.

RESULTS

Immunohistochemical analysis showed that recombinant adenovirus could transfer p53 gene into tumor cell with 98% efficiency. Western blot indicated that p16 and p53 proteins were expressed at a high level in infected H358 cell. Inhibition effect of p53 gene on proliferation of H358 cell was weaker than that of p16 gene, and the combined use of both genes could completely prevent the proliferation of H358 cell. In situ end-labeling and flow cytometry indicated that p16 could result in G(1) arrest of cell cycle and did not induce H358 cells to undergo apoptosis; p53 also induced apoptosis of few cells besides G(1) arrest; and the simultaneous use of p16 and p53 genes could induce marked apoptosis of H358 cells.

CONCLUSION

p16 and p53 genes possess the synergistic inhibiting effect on growth of lung cancer cells and can cooperate to induce apoptosis of H358 cell. The combined application of recombinant p16 and p53 adenoviruses can be used as a new strategy for cancer gene therapy.

[Development of air microbe sampler with micropore filter membrane]

Dual head air microbe sampler with a large flow capacity of 100 liters per minute was manufactured. The sampler possesses simple structures, light weight, convenient operation and higher sampling efficiency, equal to 77%-96% of the grade six Anderson sampler. Sampling time is a main factor affecting sampling efficiency. This device is suitable for the determination of degree of biological clean air in clean environment and the detection of the pathogenic microbes in ward and public places and also microbes in ordinary environment.

[Test for the performance of BL3 safety laboratory in prevention the diffusion of aerosol]

The performance of BL3 safety laboratory in preventing experimental aerosol diffusion and sterilizing microbe aerosols through high efficiency filter in a ventilation system was tasted. Aerosols of uranin, vibrio phage and Bacillus subtilis var. niger spores were used for the test. The results showed that the safety cabinets and the negative pressure room in the BL3 safety laboratory were effective. The sterilization efficiency by the combination of ozone, ultraviolet and high efficiency filter in a ventilation system of the laboratory was satisfactory. However, the position of fan and the leakage of ventilation ducts must be improved.

Studies on multiple forms of maltotetraose-forming amylase from Alcaligenes sp

Zymograms of the cultural supernatant of Alcaligenes sp. showed three bands, the major one being G4A-1 and the minor two, G4A-2 and G4A-3. Based on the electrophoretic homogeneity of the purified three bands and the enzymatic activities identified by a thin layer chromatography of the soluble starch hydrolysates, all the three bands were confirmed to be maltotetraose-forming amylase but in multiple forms. Neither glycosidase nor protease activities could be detected in the culture (only very weak protease activities were observed at 48 hours after cultivation), which indicate that the two enzymes were not involved in the amylase multiple-form formation. Only the relative amount of the two minor bands (but not the multiple-form pattern) was changed when the initial pH of the medium varied from 6.5-8.5. An addition of 0.3% glucose raised the yield of G4A-2 and G4A-3.