An improved method to develop cell culture model of intermittent hypoxia

AIM: To establish and validate a novel model of cultured cells for imitating intermittent hypoxia. METHODS: In a chamber with experiment cabin and simulated air control cabin, the frequency and duration of the intermittent hypoxia model according to the time of hypoxia and reoxygenation were evaluated. The A549 cells were randomly divided into 7 groups, named as control (Con) group, 6 h intermittent hypoxia (6IH) group, 9 h intermittent hypoxia (9IH) group, 6 h simulated air control (6AC) group, 9 h simulated air control (9AC) group, 4 h sustained hypoxia (4SH) group, 6 h sustained hypoxia (6SH) group, respectively. When the model was established, the cellular morphology was observed under inverted microscope. The mRNA expression of hypoxia-inducible factor (HIF)-1α was detected by real-time PCR. The protein expression of HIF-1α was analyzed by immunohistochemistry. RESULTS: The intermittent hypoxia cycle (5% O₂ 60 min-20% O₂ 30 min for 6 cycles) was established. The damaged A549 cells were observed in 6IH group, 9IH group and 6SH group. Compared with 6IH group, the expression of HIF-1α at mRNA and protein levels was significantly increased in 9IH group (P<0.05). The expression of HIF-1α at mRNA and protein levels in 6IH group and 9IH group was higher than that in 4SH group and 6SH group, respectively (P<0.05). No significant difference among the control group, 6AC group and 9AC group was found. CONCLUSION: The model (5% O₂ 60 min-20% O₂ 30 min for 6 cycles) can simulate the pathological process of obstructive sleep apnea hypopnea syndrome. This model is suitable for studying intermittent hypoxia in adherent cells.     

Irradiance and spectral distribution control system for controlled environment chambers

This paper describes a closed-loop control system for controlling the irradiance and spectral quality generated by fluorescent lamps in a controlled environment chamber. The 400 to 800 nm irradiance and the ratio of the red waveband (600 to 700 nm) to the far-red waveband (700 to 800 nm) were independently controlled and varied as functions of time. A suggested application is to investigate the possibility of synergistic effects of changing irradiance levels and changing spectral distributions on photoperiodism and photomorphogenesis.     

青山湖不同植物群落空气负离子效应评价

以临安市青山湖湿地公园典型植物群落常绿阔叶林、香樟林、池杉林及人工林为研究对象,研究4种不同植物群落空气负离子效应及其空气清洁度的比较。研究结果表明,不同植物群落空气负离子浓度大小排序为常绿阔叶林〉人工林〉香樟林〉池杉林,常绿阔叶林空气负离子浓度最高,环境调节功能最强,其对改善湿地公园环境质量发挥着重要的作用。     

Effects of environmental variables and cropping on plant water status of custard apple {Annona cherimola X Annona squamosa)

Several studies were conducted to develop reliable methods of measuring and sampling custard apple trees for determination of plant water status. Compared with laboratory dewpoint hygrometer, in-situ psychrometer and relative water content, the pressure chamber (because of its portability and reliability of measurement) was the most suitable technique for measuring plant water status. Custard apple leaves were shown to have a low modulus of elasticity (<8.5 MPa) and leaves were shown to adjust osmotically diurnally (0.14 MPa) and after several slowly developing water stress cycles (0.29 MPa). The level of osmotic adjustment is low compared with other crop species. In both controlled environment room and field studies, air temperature was shown to be the most important environmental variable to influence plant water status. Bearing trees exhibited higher stress levels than non-bearing ones and flowers and fruitlets exhibited more stress than leaves suggesting that reproductive organs may be more appropriate sampling organs than leaves.     

Effects of normal pregnancy on anterior chamber-associated immune deviation in primates

AIM:Recently it was found that loss of anterior chamber-associated immune deviation (ACAID) was associated with normal pregnancy in rabbits. The purpose of this study is to further investigate whether the same events occurred in nonhuman primates. METHODS:Mid-pregnant cynomolgus monkeys were randomly selected. Bovine serum albumin (BSA) or balanced salt solution was inoculated in anterior chamber of eyes of nonpregnant and mid-pregnant monkeys that were subsequently immunized with BSA in adjuvant and then skin was challenged for delayed-type hypersensitivity with BSA. RESULTS: Non-pregnant monkeys of intracameral BSA were able to acquire antigen-specific suppression of delayed-type hypersensitivity. By contrast, inoculation of BSA to anterior chamber of pregnant monkeys abolished the DTH-suppression effect. CONCLUSIONS: This is the first demonstration in primates that loss of anterior chamber-associated immune deviation occurred during normal pregnancy. The fluctuations of systemic hormone levels during normal pregnancy might influence local immunoregulation within the eye.     

Associations between green space,air pollution and birthweight in Sydney Metropolitan Area,Australia

Growing number of evidence have reported that exposure to air pollution was associated with unfavourable birth outcomes while increased exposure to green spaces was associated with better birth outcomes. However, the effect of interactions between air pollution and green spaces on pregnancy outcomes remain unclear. Using the data on all the live births recorded in Sydney between 2016 January and 2017 December, we built up multilevel linear and logistic regression models with random intercepts for statistical area level 2 (SA2) to examine the association between residential levels of air pollution (NO2, PM2.5, SO2 and O3) and pregnancy outcomes including birthweight, low birthweight, and preterm birth. This was followed by assessment of potential effect modification by green space quantity by fitting 2-way interaction term between each air pollutants and green space quantity separately. Furthermore, building on the 2-way interaction term, we explored 3-way interactions by adding area level socio-economic status and population density. Higher levels of PM2.5, NO2 and SO2 were statistically significantly associated with decrease in birthweights (p < 0.05) in the adjusted models. We observed statistically significantly association between the lower risks of preterm birth and higher levels of NO2 in the adjusted models (p < 0.05). However, none of the other air pollutants were statistically significantly associated with the odds of low birthweight and preterm birth. In the adjusted models, green space quantity was statistically significantly associated with reduced odds of preterm birth (p < 0.05). The results for birthweights were in the same direction (p < 0.05) however, some of these associations did not remain statistically significant after adjusting the models for air pollution. In general, no associations were found for low birthweight. Statistically significant 2-way interactions between green space quantity and NO2, PM2.5 and SO2 levels indicated that association between moderate levels of NO2, PM2.5 and birthweight weakened in the greener areas (>20 %) especially in the affluent and densely populated areas while the effect of SO2 did not differ consistently across green space levels with benefit of exposure to the greenest areas (>40 %) was evident, yet not statistically significant. Our findings suggest that increasing green spaces in cities may help supporting a healthy start in life by decreasing harms of moderate levels of air pollution. Replication in different contexts and consideration of potentially contrasting results with different types of green space is warranted.     

云栖竹径公园空气负离子生态效益评价

以杭州市云栖竹径公园典型植物群落毛竹纯林、常绿阔叶林及毛竹、枫香混交林为研究对象,研究3种不同植物群落空气负离子变化及其与气象因子之间的关系。研究结果表明,不同植物群落空气负离子浓度大小排序为毛竹林>毛竹+枫香混交林>常绿阔叶林,毛竹纯林具有更加强的环境气候调节效应,在改善城市气候方面发挥着重要的作用。     

太阳能蓄热系统在日光温室中的应用效果

针对如何提高冬季日光温室的温度,为作物提供适宜的生长环境,研究一套应用于日光温室的太阳能蓄热系统,该系统白天将太阳能吸收并转化为水的热量,夜间通过地热管网将热量传递给土壤,进而提高气温。在3种不同气象条件下,根据热量流动规律,计算出太阳能集热器平均效率40.6%;太阳能蓄热系统平均蓄热效率70.9%,保温蓄水池水温升高18.0℃;太阳能蓄热系统的地下平均蓄热量55.6MJ,室内夜间平均气温13.9℃,提高4.4℃;室内-20cm和-40cm土壤温度均维持在19℃,提高3～5℃,表明太阳能蓄热系统有良好的蓄热能力,能够有效提高日光温室内气温与地温,为蔬菜作物提供适宜的生长环境。     

An empirical model to simulate sodium absorption in roses growing in a hydroponic system

Modelling nutrient absorption can contribute to the management of hi-tech cultivation systems in greenhouse horticultural production. Nevertheless, previous studies to understand the kinetics of nutrient absorption, rarely take into consideration the accumulation of salt ions in the nutrient solution. In this project we develop and validate an empirical model for sodium uptake concentration in hydroponic rose (Rosa spp. cv. Kardinal) production. Model development and validation was conducted using a series of experiments in both greenhouse and growth chamber conditions. The model framework takes into account plant developmental stage and external sodium concentration. While model calibration data were collected at levels of sodium up to 40 mol m³ NaCl as root environment salt concentration, model validation was carried out at lower ranges.The proposed model not only shows a high predictive capability, but also provides useful output parameters such as electrical conductivity, which is the main parameter currently monitored for managing nutrient solution in greenhouse cultivation. Incorporated as part of a larger DSS, our model can be used to improve nutrient solution management in production regions that do not have economically valid alternatives other than the use of poor quality (saline) irrigation water.     

EEG changes of front association cortex in heroin-induced CPP rats detected by wireless telemetry

AIM:To analyze the relationship between the electroencephalogram(EEG) changes of front association cortex(FrA) and the drug-seeking behavior by recording FrA EEG in heroin-induced conditioned place preference(CPP) rats. METHODS:A CPP video system combined with the technique of EEG wireless telemetry was used in the study. The rats were randomly divided into control group and heroin-induced CPP group after stereotaxic electrodes were buried on in the FrA, and the latter group was used as heroin dependence model. The FrA EEG was recorded by wireless telemetry,including staying in black or white chamber of video box, black-white chamber shuttle and white-black chamber shuttle. The differences of EEG were analyzed by the relative power and the percentage of each wave. RESULTS:When the rats stayed in the black or white chamber, no significant difference in the relative power and percentage of the telemetry EEG wave was observed(P>0.05). When the heroin-induced CPP rats shuttled between two chambers, especially shuttled between the black-white chambers, EEG on the left FrA showed that δ wave was reduced, and β wave together with β₂ wave was increased(P<0.05, P<0.01), while the EEG in control group showed the radically opposite changes. CONCLUSION:The specific changes of EEG on the left FrA including reduction in slow wave and increase in fast wave may be related to drug-seeking behavior and motivation in the rat withdrawal status.     

Greenhouse gas fluxes in an open air humidity manipulation experiment

Air moisture is one of the main factors causing the greenhouse effect, but humidity has not been thoroughly studied at the ecosystem level. In 2006 a free-air humidity manipulation (FAHM) facility was established in Estonia to investigate the effect of humidity on the performance of two tree species—silver birch (Betula pendula Roth.) and hybrid aspen (Populus tremula L. × P. tremuloides Michx.). The trial is located on an Endogleyic Planosol of former arable land and offers the opportunity to change relative air humidity through controlled artificial misting and drying. We measured the CO₂, CH₄ and N₂O emission from the FAHM system using closed chamber and gas-chromatograph techniques from July 2009 to October 2010. Measurements were carried out once a month in three humidification (h) plots and in three control (c) plots. The vegetation period was rainy in 2009, but the next summer was relatively dry. The dry summer interacted better with the humidification. The CO₂ flux decreased when the air moisture was higher than in the control plots. The soil acted as a sink for methane. Less CH₄ was oxidized in the soil with increased humidity. Emission of N₂O did not correlate with air humidity, although one could observe a clear tendency that there was a smaller N₂O flux during the period with increased humidity. Expectedly, CO₂ emission and CH₄ consumption demonstrated strong positive correlations with soil temperature.     

Effects of CADM1 overexpression on proliferation and invasion of human gastric carcinoma cell line MKN-45

AIM: To investigate the effects of CADM1 overexpression on proliferation and invasion of human gastric carcinoma cell line MKN-45. METHODS: The protein levels of CADM1 in 3 human gastric carcinoma cell lines were detected by Western blotting. Eukaryotic expression vector pcDNA-CADM1 was constructed and transfected into MKN-45 cells. The MKN-45 cells stably expressing CADM1 were selected by G418 and identified by Western blotting. Furthermore, CCK-8 assay and Boyden chamber were used to analyze the effects of CADM1 overexpression on the prolife ration and invasion of gastric carcinoma cells. Western blotting was also utilized to detect the levels of cell proliferation- and invasion-related proteins. RESULTS: Relative level of CADM1 protein in MKN-45 cells was significantly lower than that in MKN-28 cells and SGC-7901 cells. Additionally, eukaryotic expression vector pcDNA-CADM1 was successfully constructed and MKN-45 cells stably expressing CADM1 were obtained. Compared with non-treatment and pcDNA3.1 groups, the proliferation of MKN-45 cells was obviously inhibited in pcDNA-CADM1 group. The result of Boyden chamber showed that the migrated cell numbers in pcDNA-CADM1 group (52.35±3.89) were significantly lower than that in untreated group (101.53±6.89) and pcDNA3.1 group (98.77±7.03). Compared with non-treatment and pcDNA3.1 groups, the protein level of p21 was significantly up-regulated and protein expression of MMP-2 and MMP-9 was obviously down-regulated. CONCLUSION: Overexpression of CADM1 may markedly inhibit cell proliferation and reduce invasion ability, and thus may be a novel target for treating gastric carcinoma.     

荔枝生产相关的水分生理指标远程监测研究

利用植物远程监测系统对荔枝园中的大气温湿度、土壤湿度、光照强度、大气蒸汽压差(VPD)等环境因子和茎干直径微变化、果实生长、叶片温度等树体生理指标进行了监测,发现该系统能准确及时并无伤害地记录他们的实时和周期性变化。据获得的数据初步表明,当果实处于快速膨大期,主茎的加粗生长明显缓慢,一旦果实采收后,茎干加粗生长则有一个迅速上升的变化;当土壤湿度高于33%(v/v)时,主茎的生长受到明显的抑制;VPD白天上升,夜间下降,当夜间VPD始终高于0,就形成所谓的“夜间干燥”,VPD的这种变化对荔枝主茎和果实的生长以及叶气温差(LATD)都有较大的影响,如主茎和果实的日间收缩量随VPD的增大而增大,夜间空气干燥不但抑制了主茎生长,也使日最大LATD下降。据此认为,果实和茎干的生长之间存在竞争关系,土壤湿度过高或者夜间空气干燥对荔枝的生长不利。     

Effect of street trees on microclimate and air pollution in a tropical city

One of the fastest growing cities in India, Bangalore is facing challenges of urban microclimate change and increasing levels of air pollution. This paper assesses the impact of street trees in mitigating these issues. At twenty locations in the city, we compare segments of roads with and without trees, assessing the relationship of environmental differences with the presence or absence of street tree cover. Street segments with trees had on average lower temperature, humidity and pollution, with afternoon ambient air temperatures lower by as much as 5.6 °C, road surface temperatures lower by as much as 27.5 °C, and SO₂ levels reduced by as much as 65%. Suspended Particulate Matter (SPM) levels were very high on exposed roads, with 50% of the roads showing levels approaching twice the permissible limits, while 80% of the street segments with trees had SPM levels within prescribed limits. In an era of exacerbated urbanization and climate change, tropical cities such as Bangalore will have to face some of the worst impacts including air pollution and microclimatic alterations. The information generated in this study can help appropriately assess the environmental benefits provided by urban trees, providing useful inputs for urban planners.     

A whole-plant, open, gas-exchange system for measuring net photosynthesis of potted woody plants

Chambers were constructed to measure gas exchange of entire potted grapevines (Vitis vinifera L.). The plant enclosures were constructed from Mylar film, which is nearly transparent to photosynthetically active radiation. Maintaining a slight, positive, internal pressure allowed the Mylar chambers to inflate like balloons and required no other means of support. The whole-plant, gas-exchange chamber design and construction were simple and inexpensive. They were assembled easily, equilibrated quickly, and did not require cooling. They allowed for the measurement of any plants in a relatively short period. This system would enable the researcher to make replicated comparisons of treatment influences on whole-plant CO2 assimilation throughout the growing season. While CO2 measurement was the focus of this project, it would be possible to measure whole-plant transpiration with this system.     

Growth responses of some greenhouse plants to environment. III. Design and function of a growth chamber prototype

Growth chambers for the study of effects of temperature, air humidity and CO₂-concentration on plant growth, with or without supplementary artificial light, are described. Each chamber has a volume of 1080 1. The mean airflow at plant level is 0.22 m s^?1. The temperature is controlled within ± 0.5°C in the range from 10°C lower to 20°C higher than the ambient temperature at low solar radiation. In direct sunshine, the temperature may rise 1°C at floor level and the gradient from the floor to the upper part of the chamber may be about 2°C.The relative humidity is generally controlled within ± 4%, in the range from 50 to 95%.The CO₂-concentration is controlled within ± 5% of the desired value. The number of air changes in the chambers may be controlled from 0 to 20 h^?1.Tests revealed no significant difference between the chambers with respect to fresh weight production of lettuce, rose or chrysanthemum. There was, however, a significant effect from the position within the chambers.     

Expression of bFGF mRNA in pulmonary artery of rat with chronic hypoxia and its effect on tension of rat pulmonary artery in vitro

AIM: To explore the role of basic-fibroblast growth factor (bFGF) in the development of pulmonary hypertension induced by hypoxia. METHODS: 1) The pulmonary arteries of SD rats with hypoxia for one and two weeks were isolated, from which the total RNA were extracted by acid guanidinium thiocyanate-phenol-chlorform .Then the levels of mRNA were measured by RT-PCR. 2) About 3mm-long arterial rings cut from SD rat pulmonary arterial stem were suspended between stainless steelhooks in chamber with warmed (37℃) Kreb's solution. Different concentrations of bFGF were added in a cumulative fashion into the chamber where the rings were suspended. The cumulative concentration response curve was obtained. RESULTS: 1)The levels of bFGF mRNA in pulmonary artery of rats with hypoxia were increased significantly compared with those that without hypoxia (2578±384 counts·min^-1 (control) vs 5303±756 (hypoxia) for 1 week and 4054±547 (hypoxia) for 2 weeks, P all ＜0.05). 2) bFGF at concentrations ranged from 5.56×10^-10~2.78×10^-7mol/L caused dose-dependent contraction of vessel rings of rat pulmonary artery (r=0.695,P＜0.05), with EC₅₀ being 2.62×10^-7mol/L. CONCLUSION: bFGF may play an important role in the hypoxic pulmonary hypertension.     

重庆花园式屋顶绿化生态效益的初步研究

为了探讨屋顶绿化的生态效益,2013年7月选取重庆市园林事业管理局花园式屋顶绿化作为研究对象,以无绿化植物的屋顶水泥地作为对照,进行“乔-灌”、“灌-草”和草坪三种不同植物配置模式的气温、空气相对湿度、地表温度和空气中负氧离子含量测定。研究结果表明,屋顶绿化具有重要的生态效益,且不同植物配置模式的生态效益有较大差异。降温幅度为“乔－灌”（3．60℃）〉“灌～草”（2．68℃）〉草坪（1．43℃）,增湿幅度为草坪（29．42％）〉“乔-灌”（17．68％）〉“灌-草”（9．46％）,对地表温度的降低程度“乔－灌”（25．55℃）〉草坪（20．67℃）;屋顶绿化空气负氧离子含量此对照高33．73ions／m^3。     

Effect of growing medium water content on the biological control of root pathogens in a closed soilless system

Summary

The water content of the growing medium and its interaction with a biocontrol agent was studied in a closed soilless culture system in order to identify factors that could increase the efficiency and decrease the variability of biocontrol agents. Pumice was chosen as the growing medium because of its high water-holding capacity and in view of the high water content required for the growth of the root pathogen. The commercial biocontrol agent Binab T (active strains Trichoderma polysporum and T. harzianum) was evaluated at 50% and 70% water content. Studies were carried out in a controlled environment, in a climate chamber, using tomato as the model plant and Pythium ultimum as the model pathogen. Pathogen levels were affected by the water content of the medium and the biocontrol treatment, while the amount of biocontrol agent was not affected by the water content of the growing medium. The Trichoderma strains in Binab T were able to reduce the amount of pathogen and the incidence of disease at both water contents tested. The biocontrol activity of Binab T against P. ultimum, as indicated by the level of glucanase production, was affected by variations in the water content of the growing medium. The pathogen, the biocontrol agent, and the water content of the growing medium, all had an impact on the microbial communities resident in the system.     

Effects of curcumin on migration and invasion of myeloma cells

AIM：To explore the effect of curcumin on the migratory and invasive abilities of myeloma cells. METHODS：shRNA expression plasmid was transfected into RPMI8226 cells to knock down IQ motif-containing GTPase-activating protein 1 (IQGAP1). The expression of IQGAP1 in RPMI8226 cells tranfected with shIQGAP1 or shRNA negative control, and in un-transfected RPMI8226 cells was detected by Western blotting. All the cells in RPMI8226-shIQGAP1 group, RPMI8226-shRNA negative control group and un-transfected RPMI8226 group were treated with curcumin at various concentrations. The migratory and invasive abilities of the RPMI8226 cells were measured by Transwell chamber and Matrigel assays. The expression of IQGAP1 at mRNA and protein levels in the RPMI8226 cells treated with curcumin was also determined by RT-PCR and Western blotting. RESULTS：The expression of IQGAP1 decreased when IQGAP1 gene was knocked down by shRNA. The migration and Matrigel invasion tests showed that the number of cells moving into under chamber of Transwell decreased in RPMI8226-shIQGAP1 group in comparison with the other 2 groups. Curcumin decreased the migratory and invasive abilities of RPMI8226-shRNA negative control cells and un-transfected RPMI8226 cells, which was not related to the curcumin concentratory. The migratory and invasive abilities of RPMI8226-shIQGAP1 cells showed no significant difference when treated with curcumin at various concentrations. The expression of IQGAP1 at mRNA and protein levels decreased in the RPMI8226 cells treated with curcumin. CONCLUSION：Curcumin decreases the migratory and invasive abilities of myeloma cells via inhibition of IQGAP1 expression.