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1.
A beta-ray gauge system was used to study evaporation rates and drying times of liquids exposed to relatively high fluxes of air ions of either polarity produced by a corona discharge. Evaporation rates from thin layers of water, ethyl alcohol, and carbon tetrachloride increased considerably when exposed to air ions, compared to untreated liquids under constant environmental conditions. Drying times of liquid layers exposed to air ions were shortened by a factor of at least two over liquids that had not been exposed to ions. The drying time of a liquid layer was found to increase with the decrease of ion fluxes at the liquid surface. Threshold values of 1.9×1011 positive ions and 2.7×1011 negative ions cm–2 s–1 were established below which no increase in the evaporation rates were observed for ethyl alcohol and carbon tetrachloride. The evaporation rate of water at these same ion fluxes was significantly higher than that of the control. The present experiments indicate that a stream of air ions could play a major role in the observed enhancement of evaporation rates.  相似文献   

2.
Effect of air ions on submicron t1 bacteriophage aerosols   总被引:3,自引:3,他引:0       下载免费PDF全文
The effect of a high concentration of ionized air molecules on sampling T1 phage aerosols of submicron particle size was evaluated by comparing the phage recoveries of all-glass impingers (AGI-4) and type 6 filter papers. Sampler recoveries of all ionized aerosols were less than the recoveries of nonionized control aerosols. These reductions in recovery were greater with positive ions than with negative ions or ions of mixed polarity. The AGI-4 allowed considerable slippage, which was not affected by the air ions. Type 6 filter paper recoveries were less than AGI-4 recoveries. The air ions did not appear to affect the aerosol particle size as determined by an electron microscope.  相似文献   

3.
Rats exposed during three weeks to high concentrations of positive air ions (80,000 ions/ml) exhibit signs of lowered brain arousal. Amplitude of electrocorticograms recorded with fronto-frontal and occipito-occipital derivations increases. Amplitude of theta hippocampic rhythm increases as the frequency decreases. Power spectrum analysis of theta hippocampic rhythm shows that the low frequency band (5.6 Hz) is the most enhanced one.Similar exposure to negative air ions induces modifications that are not so important. The frequency of theta hippocampic rhythm is, however, significantly increased. A slight increase in vigilance level is probable.These different effects of air ion polarity on vigilance level could explain some effects of air ions upon acquisition task.  相似文献   

4.
Space charges (air ions) produced by a single point-to-plane corona electrode system were used to study the enhancement in the evaporation rates of water at three ion current levels. The maximum evaporation rates of 0.019 and 0.017 g·min?1 were observed at a 1 cm electrode gap for negative and positive air ions, respectively. The cumulative evaporation rates were linear with time and an ion-enhanced rate was about 4 times greater than the control. The current density distribution measurements agreed fairly well with those predicted from the Warburg law. The principal driving force for the observed evaporation enhancement was an ion drag phenomenon which created vortex motions in water when air ions were subjected to an externally applied electric field. Theoretical considerations from derived relationships in fluid mechanics demonstrate that the mass transfer coefficient is higher for positive than negative ions of the same current strength because of the mobility difference between the charges in the medium.  相似文献   

5.
Controlled experiments were performed in Faraday cages on the effects of positive and negative air ions on flue-cured tobacco plants. Continuous exposures for 15 days to air ions showed no significant differences in any plant growth characteristic between the treated and control plants. Standard errors in the measurement of the growth parameters for ion exposed plants were, however, consistently higher than those of control plants. Spatial variation in concentration gradients of air ions produced by corona discharge might have contributed to masking of the relatively small effects of air ions on biological organisms observed in previous experiments in this laboratory. No significant difference was observed between the experimental and control plants in nicotine, total alkaloid, and reducing sugar contents. Total nitrogen content was slightly higher for treated than control plants.  相似文献   

6.
Stem height increases of 13% and 15% for barley and snapdragon respectively were observed for plants maintained in an atmosphere of high concentrations of negative air ions compared to control plants. Dry weights of the exposed plant species to negative ions increased by approximately 18% compared to untreated plants. The effects of positive air ions were insignificant. The rates of photosynthesis and respiration measurements on continuously exposed plants to negative air ions conformed to these observations.  相似文献   

7.
Effects of host — pathogen interactions with respect to relatively high concentrations of artificially produced air ions were studied in the laboratory. Continuous and long exposures ofHelminthosporium teres in the culture medium and under controlled conditions to positive air ions, produced a time — delay of about 6 hours on spore germination. Negative ions produced no such effect. Temporary structural abnormalities of the germ tubes were observed for two to three hours when exposed to either positive or negative air ions. Sprayed inoculum of spores on actual leaf surfaces of barley plants, exposed to positive ions, suppressed germination for a considerably longer time than those observed in the culture medium.  相似文献   

8.
 An electrohydrodynamic (EHD) system with a point-to-plane electrode, which produced air ions within a strong electric field, was used to study mortalities of pupae, larvae, and adults of Tribolium confusum (TC) and larvae of Plodia interpunctella (PI). The treatments included a neutral air stream, negative ions, positive ions, and the air stream superimposed with ions of either polarity. The negative ions caused the maximum mortality in TC pupae and PI larvae whereas the TC adults were least affected, but the negative ion flux was higher than the positive one at the constant high voltage of the power supply used in the present experiments. The differences in the mean mortalities of the treatment groups were highly significant (P<0.0001). Mortality was primarily attributed to the body fluid losses caused by the electric wind of the EHD system. Mortality and weight loss relationships were linear with negative slopes (r 2=0.52, and r 2=0.98 for TC and PI, respectively). The superimposition of the air stream with either positive or negative ion fluxes increased the survival fractions compared with those of the ion fluxes alone. Received: 27 May 1996 / Accepted: 9 September 1996  相似文献   

9.
Techniques have been devised for studying quantitatively the effects of air ions on microorganisms suspended in small drops. In smog-contaminated atmospheres moderate concentrations of positive and negative air ions exerted a protective effect on staphylococci by delaying the drop in pH customarily observed and by diminishing the rate of evaporation. In clean air higher concentrations of positive and negative air ions accelerated the rate of death of staphylococci apparently by direct action on the cells and by increasing the rate of evaporation. Air ion action in these experiments did not involve cell agglutination or direct radiation from the radioactive isotopes employed.  相似文献   

10.
A consequence of the Chernobyl disaster was the isolated increase of small air ions for a limited time period over Athens-Greece. Taking advantage of this unique condition we studied the relation of log daily mean concentrations of small positive air ions, small negative air ions, NO2 and SO2 with the total daily number of asthma attacks attendances at the region's largest chest diseases hospital for 35 days following the disaster and during a same time period in the preceding four years. No correlation was found between air ionization and asthma attacks, though the study was of a rather short duration and several possible influencing factors such as aeroallergen concentrations were not taken into consideration.  相似文献   

11.
The investigation showed that positive and negative air ions have opposite general effects on the structure of sleep in rats. When submitted to positive air ions, the animals consecutively exhibited during sleep an EEG with increased amplitude and lowered frequency. This decrease in vigilance level is nevertheless accompanied by obvious signs of a disturbed sleep, that is: more polyphasic sleep and decrease of slow wave sleep which is the most efficient for physical restoration. The generally opposite action of negative air ions is consistent with their effects described by other authors who have studied human sleep after aeroionotherapy. The general paradigm of air ion action on sleep is in agreement with implications of recent sleep theories.  相似文献   

12.
The ability of air ions to produce changes in the electrical properties of L 1210 mouse leukemia cells was tested. The fluorescence of ANS incorporated into a membrane lipid bilayer (measured microphotometrically) was used as a probe. It was shown that the action of air ions of both signs could change (negative ions by increasing and the positive ones by decreasing) the fluorescence intensity of ANS in the cell surface structures or to an imbalance of ions inside and outside the cell. Both possibilities are discussed in the light of the results of experiments using ouabain or biguanide as factors diminishing the intensity of ANS fluorescence.  相似文献   

13.
We report on the epidemiology of tattoo disease in a community of bottlenose dolphins Tursiops truncatus from the Sado estuary, Portugal. The presence of tattoos (T++) and tattoo-like (T+) lesions was examined in 586 photographic records of 35 dolphins taken from 1994 to 1997. Images were rated into 3 categories: good (GI), average (AI) and poor (PI). Dolphins positive for T++ lesions were observed in 19 GI. Dolphins with T+ lesions were seen in 39 GI, 23 AI and 6 PI. For statistical analysis the dolphins were divided into 2 age classes (immature and adult) and the data grouped into 2 periods (1994-1995 and 1996-1997). Minimum prevalence of T++ lesions in 32 dolphins was 21.9% in 1994-1995 and 15.6% in 1996-1997. Variation in prevalence of tattoo disease between the 2 age classes was examined for each period, excluding animals with T+ lesions or considering them either positive or negative for tattoos. Prevalence of the disease was significantly higher in immature dolphins than in adults during both periods, except in the first one when T+ lesions were considered as true tattoos. Temporal variation in prevalence of tattoo disease was examined in 23 adults. Prevalence was significantly higher in 1994-1995 (39.1%) than in 1996-1997 (17.4%). Differences in the number and quality of pictures did not cause significant biases that could have favoured the detection of lesions between age classes or periods. Minimal persistence of the disease ranged between 3 and 45.5 mo. The lesions converted into light grey marks when healing, but may recur. The presence of very large lesions in 2 adult dolphins affected for years may be related to the contamination of the estuary. The high prevalence of the disease, its long persistence, as well as higher frequency in immature individuals, suggest that it is endemic in bottlenose dolphins from the Sado estuary. The contribution of tattoo disease to the decline of this community should be investigated. Three of the 5 dolphins that died during this study had T++ and T+ lesions.  相似文献   

14.
Mice were maintained in a controlled pollutant-free microenvironment and were exposed for 12, 24, 48 and 72 hr to 3 different concentrations of small positive or negative air ions: 2–4 × 103 ions/cm3, 3–4 × 104 ions/cm3 or 3.5–5 × 105 ions/cm3. Spectrophotofluorometric assays of brain serotonin levels of air ion-treated mice showed statistically significant differences as early as 12 hours from those of mice kept in untreated pollutant-free air. Essentially no deviation from control values were observed at 24 and 48 hours. After 72 hours of exposure sharp decreases took place in all groups with the single exception of the animals exposed to 3–4 × 104 positive ions/cm3. The hypothesis that alterations in mood and affect associated with certain meteorological conditions, e.g. winds such as the foehn, sirocco, etc. might depend upon air ion-induced changes in brain levels of serotonin was examined in the light of recent advances in neurophysiology and neuropharmacology.  相似文献   

15.
When submitted to a single avoidance task male mice showed different behavioral responses if previously treated with opposite aeroionization polarities. Whereas negative air ions tend to improve learning, positive ions have disturbing effects. Male rats submitted to a single — trial inhibitory avoidance step-through task showed that retention processes may also be influenced by air ions. The positive air-ion-treated animals exhibit signs of impaired short and long term memory. The slightly impaired score of negative air-ion-treated animals seems only dependent upon the simultaneously increased locomotor activity. A separate experiment supported this hypothesis showing conspicuous differential effects of air ion polarity on spontaneous activity of male rats. On the basis of these findings and the results of other studies in biological air ion dependence field, the behavioral significance of aero-ionization in learning and memory processes is discussed in relation to serotonin metabolism and other neuroendocrine mechanisms.  相似文献   

16.
The brain induced activity was studied in 18 rats wearing chronically skull implanted electrodes. The stimulating factor was various electrical stimulations of the mesencephalic reticular activating formation, given during the slow wave state of sleep. The results of 300 stimulations were measured by amplitude and frequency changes in the EEG simultaneously recorded. Animals previously exposed to positive air ions (3 weeks 80,000 ions/ml) exhibited lowered excitability of the reticulocortical system. Significantly higher stimulations were necessary to induce arousal. Negative air ions induced more intricate effects: brain excitability was lowered when tested with weak stimulations, but normal when evaluated with medium high level stimilations. Sleep seems first more stable but as stimulation increases, arousal is soon as effective as in controls. These results are in agreement with others findings in behavioral fields and partly explains them.  相似文献   

17.
Hot dry winds (Sharav) produce increased ionisation of the atmosphere, values for positive and negative ions going up from an average of 1, 000 per cm3 to 1, 500. There was almost always a slight preponderance of the positively-charged small ions. This increased air ionisation induces serotonin release in about one-quarter of the population with multiple complaints of a typical serotonin irritation syndrome. In 75% of 129 subjects suffering from serotonin ailments, the treatment with negative air ions (Ionotron) with an output of 3.5 × 105 ions/(cm3 · sec) at 1 m distance produced prophylactic and therapeutic relief when the patients were kept in a room of up to 4 × 4 m size. These results were controlled by serotonin and 5-HIAA urinalysis.  相似文献   

18.
The indirect immunofluorescence test (IF) for anti-Leishmania antibodies (IgG and IgM) was performed with sera from the following groups of individuals: 214 cutaneous leishmaniasis patients, 28 healthy subjects with positive Montenegro's skin test (MST), 29 healthy subjects with negative MST and 16 visceral leishmaniasis patients. The first four groups came from a suburban area of Rio de Janeiro (Jacarepaguá) where cutaneous leishmaniasis caused by Leishmania braziliensis braziliensis is endemic. It was observed that IF-IgM titers were significantly higher amongst the cutaneous leishmaniasis patients with less than four months of disease as compared to those with longer periods and that IF-IgG titers were significantly higher in patients with multiple lesions as compared to those with single lesions. The visceral leishmaniasis patients had IF-IgG titers significantly higher than those from cutaneous leishmaniasis patients. A group of 28 individuals selected amongst the 214 cutaneous leishmaniasis patients had their IF-titers (IgG and IgM) compared to those of the two control groups of healthy subjects from the endemic area, respectively with positive and negative MST. Significantly higher titers of IF-IgG and IF-IgM were found in the group with active disease. The same group of patients showed IF-IgG titers significantly lower at the end of the antimonial therapy than those observed during this treatment.  相似文献   

19.
The effect o 4 weeks dietary administration of the hormone dehydroepiandrosterone (DHEA) on enzyme and morphological phenotype of focal lesions previously induced by dimethylaminoazobenzene (DAB) treatment was investigated in Sprague-Dawley rats. In contrast to the DAB-alone livers where large numbers of glycogen-storing, mixed cell nodules homogeneously positive for glutathione S-transferase P form (GST-P) were apparent, DHEA treated animals were characterized by significantly fewer, more heterogeneous lesions, in some cases demonstrating increased amphophilia and structured basophilia. The enhanced heterogeneity, in some ways reminiscent of that reported earlier for 'reversibility' or 'remodelling' of rapidly induced nodular lesions, was associated with increased catalase (CAT), acid phosphatase (AP) and glucose-6- phosphatase (G6Pase) and decreased glycogen contents and phosphorylase (PHO) activity in both nodules and background parenchyma. Glucose-6-phosphatase (G6PD) activity was elevated irregularly focal lesions also demonstrating a heterogeneous reaction. The experimental data suggest two separate effects of the hormone treatment the first involving modulation of the usual altered phenotype of preneoplastic lesions with a shift towards 'tigroid' cell character and the second, similar to that reported earlier for rapidly induced nodules, involving enhanced phenotypic instability and leading to reduction in numbers.  相似文献   

20.
A cross sectional survey investigating "building sickness" was carried out in two buildings with similar populations of office workers but differing ventilation systems, one being fully air conditioned with humidification and the other naturally ventilated. The prevalence of symptoms related to work was assessed by a questionnaire administered by a doctor. A stratified, randomly selected sample of workers was seen (84% response). Building sickness includes several distinct syndromes related to work, most of which were significantly more common in the air conditioned building than the naturally ventilated building--namely, rhinitis (28% v 5%), nasal blockage and dry throat (35% v 9%), lethargy (36% v 13%), and headache (31% v 15%). The prevalence of work related asthma and humidifier fever was low and did not differ significantly between the two buildings. An environmental assessment of the offices was performed to attempt to identify possible factors responsible for the differences in the prevalence of disease. Globe temperature, dry bulb temperature, relative humidity, moisture content, air velocity, positive and negative ions, and carbon monoxide, ozone, and formaldehyde concentrations were all measured. None of these factors differed between the buildings, suggesting that building sickness is caused by other factors.  相似文献   

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