Combined exposures of human ciliated cells to different concentrations of sulfur dioxide and nitrogen dioxide

In the present study we investigated the influence of two common air pollutants, sulfur dioxide (SO2) and nitrogen dioxide (NO2) on ciliary beat frequency (CBF). Ciliated cells were obtained by nose brush from 12 healthy volunteers and placed on a polycarbonate membrane which was in contact with Ringer's electrolyte solution. This allowed the supply of the cells by capillarity in parallel to the reaction of the pollutants with the cell surfaces. In an exposure chamber the cells were exposed for 30 min. at 37 degrees C either to SO2 (2.5-12.5 ppm) or to NO2 (3.0-15.0 ppm), or to a mixture of NO2 (12.0 ppm) and SO2 (2.5 or 5.0 ppm). CBF was measured by video-interference-microscopy. With SO2 we observed a dose-dependent decrease in CBF with Ringer's solution. 2.5 ppm SO2 caused a 42.8% decrease and 12.5 ppm a decline of approximately 100% (8.10 +/- 0.24 Hz vs. 0.28 +/- 0.20 Hz). In parallel, we observed a decrease in the pH-value from 7.4 to 3.6. 30 min. NO2 exposure (3.0-15.0 ppm) induced a significant dose dependent increase in CBF from 8.4 +/- 0.34 Hz to 9.4 +/- 0.44 Hz. Exposure to a mixture of SO2 and NO2 with Ringer's solution revealed that SO2 exerts a stronger influence on CBF than NO2. Exposure to both pollutants resulted in the same as exposure to SO2 alone. Our findings demonstrate a strong correlation between SO2-modified pH values and CBF. Exposure to a combination of two pollutants revealed the dominant influence of SO2 on CBF while the augmented effect of exposure to NO2 alone might be due to the oxidative potential of this gas.     

超声波提取紫薯多糖的工艺优化

[目的]优化紫薯多糖的提取工艺.[方法]利用超声波技术提取紫薯粗多糖,用单因素试验和正交试验设计相结合的方法获得最佳提取工艺.[结果]影响紫薯多糖得率的主要因素按重要性排序为:超声频率>料液比>提取温度>提取时间;紫薯粗多糖最佳提取工艺条件为:料液比1:15,提取时间40min,提取温度60℃,超声频率80 kHz,此条件下紫薯多糖的提取率为3.63%.[结论]利用超声技术提取紫薯多糖可以提高多糖得率、缩短提取时间、采用较低温度提取、节省提取溶剂,降低提取成本.     

Response of mosquitoes (Diptera: Culicidae) to carbon dioxide and octenol in Egypt

The radioprotective effect of the leaf extract of Ocimum sanctum (OE) in combination with WR-2721 (WR) was investigated on mouse bone marrow. Adult Swiss mice were injected intraperitoneally (i.p.) with OE (10 mg/kg on 5 consecutive days), or 100-400 mg/kg WR (single dose) or combination of the two or double-distilled water (DDW) and whole-body exposed to 4.5 Gy gamma-irradiation (RT). Metaphase plates were prepared from femur bone marrow on days 1, 2, 7 and 14 post-treatment and chromosomal aberrations were scored. The maximum number of aberrant cells was observed at 24 h after irradiation in all the groups. However, pretreatment with OE or WR individually resulted in a significant decrease in aberrant cells as well as different types of aberrations. The combination of the two further enhanced this effect; resulting in a 2-fold increase in the protection factor (PF = 6.68) compared to 400 mg/kg WR alone. The percent aberrant cells decreased linear-quadratically with WR dose when given individually, while in the OE + WR pretreatment animals the values showed a linear dose response. Combination of OE with WR doses above 200 mg/kg completely eliminated rings, polyploidy and pulverization of chromosomes. Percent aberrant cells decreased with time in all groups, though the values remained higher than normal even on day 14 in the RT alone as well as those treated with single agent + RT. WR doses above 200 mg/kg before RT resulted in significantly higher frequency of aberrant cells compared to RT and OE + RT groups on day 14, suggesting delayed WR toxicity; but combination of OE with WR brought down these values to normal level, indicating that OE combination, in addition to enhancing WR protection, may also act as a detoxifier. The protective effect of OE and WR is also reflected in the enhancement of bone marrow CFU survival. Both OE and WR possessed significant free radical scavenging activity in vitro. The combination of the two further enhanced this effect, suggesting that the enhanced free radical scavenging activity by combining the two protectors results in the higher bone marrow cell protection. The significant elevation in chromosome protection obtained by combining OE with WR, with reduction in the latter's toxicity at higher doses, suggests that the combination may have promise for radioprotection in humans.     

Chamber exposures of children to mixed ozone, sulfur dioxide, and sulfuric acid

To help assess acute health effects of summer air pollution in the eastern United States, we simulated ambient "acid summer haze" as closely as was practical in a laboratory chamber. We exposed young volunteers who were thought to be sensitive to this pollutant mixture on the basis of previous epidemiologic evidence. Specifically, we exposed 41 subjects aged 9-12 y to mixed ozone (0.10 ppm), sulfur dioxide (0.10 ppm), and 0.6-microm sulfuric acid aerosol (100 +/- 40 microg/m3, mean +/- standard deviation) for 4 h, during which there was intermittent exercise. Fifteen subjects were healthy, and 26 had allergy or mild asthma. The entire group responded nonsignificantly (p > .05) to pollution exposure (relative to clean air), as determined by spirometry, symptoms, and overall discomfort level during exercise. Subjects with allergy/asthma showed a positive association (p = .01) between symptoms and acid dose; in healthy subjects, that association was negative (p = .08). In these chamber-exposure studies, we noted less of an effect than was reported in previous epidemiologic studies of children exposed to ambient "acid summer haze."     

Reductive stripping of Fe(III)-loaded D2EHPA with the aqueous solutions containing sulfur dioxide

The stripping of Fe(III)-loaded D2EHPA, which is known to be difficult, was studied in the presence of SO₂. The stripping reaction of Fe(III) was greatly accelerated by the presence of SO₂, generating Fe(II) as a stripped species. In the presence of SO₂, the stripping of Fe(III) was favorable with all acids studied, including HC1, HC1O₄, and H₂SO₄, and even with water. Among various factors, the partial pressure of SO₂ was found to be the most important factor in controlling the rate of stripping as well as the rate of reduction of stripped Fe(III) in the aqueous phase. The removal of SO₂ dissolved in an organic phase was easily done by washing with aqueous H₂O₂ solution.     

A novel cyclic process using CaSO<Subscript>4</Subscript>/CaS pellets for converting sulfur dioxide to elemental sulfur without generating secondary pollutants: Part I. Feasibility and kinetics of the reduction of sulfur dioxide with calcium-sulfide pellets

Certain new sulfide-smelting processes and coal-gasification processes generate high-strength sulfur dioxide streams, for which a new process for converting sulfur dioxide to elemental sulfur needs to be developed because no process exists that is generally and economically applicable to the treatment of such streams. A thermodynamic and experimental investigation to develop a new process for converting sulfur dioxide to elemental sulfur by a cyclic process involving calcium sulfide and calcium sulfate without generating secondary pollutants was carried out. In this process, the starting raw material, calcium sulfate, is reduced by a suitable reducing agent, such as hydrogen, to produce calcium sulfide, which is used to reduce sulfur dioxide to elemental sulfur vapor and calcium sulfate. The latter is, in turn, reduced to regenerate calcium sulfide. In this Part I, detailed experimental results are presented on the kinetics of the reaction between sulfur dioxide and calcium-sulfide pellets, which produces elemental sulfur and calcium sulfate. The experiments were carried out at temperatures between 1023 and 1088 K and sulfur-dioxide partial pressures between 9 and 60 kPa by the use of a thermogravimetric analysis (TGA) technique. The rate of this reaction was demonstrated by the conversion of 40 pct calcium-sulfide pellets obtained from the hydrogen reduction of fresh calcium sulfate in 10 minutes at 1073 K under a sulfur-dioxide partial pressure of 43 kPa. The reactivity decreased somewhat during the first three cycles but remained largely unchanged thereafter up to the tenth cycle. This characteristic of the pellets is important because the solids must be reusable for repeated cycles to avoid generating secondary pollutants. A pore-blocking model was found to fit the reaction rate. The reaction is first order with respect to sulfur-dioxide partial pressure and has an activation energy of 101 to 134 kJ/mol (24 to 32 kcal/mol) for calcium-sulfide pellets reacted and regenerated several different times. Sulfur dioxide-containing streams from certain sources, such as the regenerator off-gas from an integrated-gasification, combined-cycle, desulfurization unit and new sulfide-smelting plants, contain much higher partial pressures of SO₂. In these cases, the rate of the first reaction is expected to be proportionally higher than in the test conditions reported in this article. The reduction kinetics of calcium-sulfate pellets with hydrogen gas is reported in the accompanying Part II.     

The trivalent cerium-induced cell death and alteration of ion flux in sweetpotato [Ipomoea batatas(L.) Lam]

The rare earth element cerium(Ce) in its several forms is extensively utilized in various fields, including nano-technology, agriculture, and the food industry. Due to its increasing unregulated usage, Ce is now a potential source of pollution and toxicity due to its excessive environmental accumulation. Unfortunately, analysis of the toxic effects of Ce in plants is still in its early stages. Herein, we investigated the effects of Ce3+ treatment on development-related indicators in sweetpotato. We found that a low concentration(10 mg/L) slightly improved oxidation resistance, while a high concentration(20-80 mg/L)negatively affected development and photosynthesis and triggered increases in reactive oxygen species(ROS) production, antioxidant enzyme activities, and malondialdehyde(MDA) content. Moreover,elevation and efflux of cytosolic Ca~(2+) and caspase-l-like activity were induced by high-concentration Ce~(3+) treatment. Finally, cell viability decreased as Ce3+ concentration increased. These results suggest that(1) a high Ce3+ concentration(20-80 mg/L) inhibits development and photosynthesis of sweetpotato and induces oxidative damage followed by lipid peroxidation in the root,(2) a caspase-l-like protease is induced by cytosolic Ca~(2+) and ROS overproduction to cause programmed cell death in the root, and(3) a high concentration of Ce3+ could trigger a hypothetical cell death pathway, wherein Ce3+induces ROS production followed by cytosolic Ca~(2+) elevation, which activates caspase-l-like activity,which in turn leads to programmed cell death in the root of sweetpotato.     

Laboratory evaluation of molluscicidal activity of extracts from Cotula cinerea (L) and Quercus lusitania var. infectoria galls (Oliv.)

In this work, we have studied the molluscicidal activity of different extracts obtained from Cotula cinerea and Quercus lusitania var. infectoria galls. The hydroalcoholic extract of Cotula cinerea, acetonic extract and gallotanin of Quercus infectoria galls have presented high activity against Bulinus truncatus. The hydroalcoholic extract of Cotula cinerea was fractionated by chromatography on silica gel column. We have isolated two very active fractions at concentrations respectively of 52.5 and 27.5 ppm.     

Antioxidant and free radical scavenging effects in extracts of the medicinal herb Achyrocline satureioides (Lam.) DC. ("marcela")

Achyrocline satureioides (Lam.) DC. (Compositae) is a medicinal herb used in Argentina, Uruguay, Brazil and Paraguay for its choleretic, antispasmodic and hepatoprotective properties. The presence of the flavonoid quercetin and its derivatives, and of different phenolic acids such as caffeic, chlorogenic and isochlorogenic acids in the aerial parts of this plant has led us to study the antioxidant activity of its extracts using different bioassays. The inhibition of luminol-enhanced chemiluminescence by the aqueous and methanolic extracts was used to show that their total reactive antioxidant potential index (TRAP; in microM Trolox equivalents) was 91.0 +/- 15.4 and 128.1 +/- 20.1 microM, respectively, while the total antioxidant reactivity index (TAR) was calculated to be 1537 +/- 148 and 1910 +/- 171 microM. Only the methanolic extract was capable of reducing iron (II)-dependent DNA damage. Lipid peroxidation was assessed by two different methods. The aqueous extract reduced hydroperoxide-initiated chemiluminescence in rat liver homogenates at all concentrations in a dose-dependent manner, with a calculated IC50 = 225 micrograms/ml, while the methanolic extract was only effective at higher concentrations (100 and 1000 micrograms/ml). Both aqueous and methanolic extracts were capable of reducing the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenates, with an IC50 > 1000 micrograms/ml. The results obtained suggest that the extracts of A. satureioides possess significant free radical scavenging and antioxidant activity in vitro, a fact that should encourage future in vivo studies.     

A novel cyclic process using CaSO4/CaS pellets for converting sulfur dioxide to elemental sulfur without generating secondary pollutants: Part II. Hydrogen reduction of calcium-sulfate pellets to calcium sulfide

The reduction of calcium sulfate to produce calcium sulfide is a part of the cyclic process for converting sulfur dioxide to elemental sulfur that is described in Part I. The kinetics of the hydrogen reduction of nickel-catalyzed calcium-sulfate pellets were investigated using a thermogravimetric analysis (TGA) technique at reaction temperatures between 1023 and 1088 K and hydrogen partial pressures between 12.9 and 86.1 kPa. The reactivity of nickel-catalyzed calcium-sulfate pellets was demonstrated by the conversion of 70 pct fresh nickel-catalyzed calcium sulfate to calcium sulfide in 20 minutes at 1073 K under a hydrogen partial pressure of 86.1 kPa. Furthermore, the reactivity remained relatively intact after ten cycles of reactions and regenerations. This observed characteristic of the pellets is important because the solids must be reusable for repeated cycles to avoid generating secondary pollutants. The nucleation and growth rate expression was found to be useful in describing the kinetics of the reaction, which had an activation energy of about 167 kJ/mol (∼40 kcal/mol) in all reaction cycles except for the first regenerated samples that were lower at 146 kJ/mol (35 kcal/mol). The reaction order with respect to hydrogen partial pressure was 0.22 in all cycles with the exception of the first regenerated sample for which it was 0.37.     

豹斑毒鹅膏菌毒素粗品对黄粉虫的毒性研究

[目的]探讨豹斑毒鹅膏菌毒素粗品对黄粉虫的毒性.[方法]测定了5种大型真菌子实体及毒素粗品对黄粉虫的毒杀活性,并对筛选出的豹斑毒鹅膏菌进行了致死效应研究.[结果]随着豹斑毒鹅膏菌毒素粗品浓度的增大,防治效果越来越明显.当豹斑毒鹅膏菌毒素粗品浓度为17.5 mg/ml时,黄粉虫死亡率为93.3%,效果显著.[结论]豹斑毒鹅膏菌毒素粗品对黄粉虫有较显著的毒杀作用.     

Analysis of the expression of two thiolprotease genes from daylily (Hemerocallis spp.) during flower senescence

Rats treated with two injections of adriamycin (week 0 and week 12) developed glomerusclerosis and severe tubulointerstitial lesions as described in the literature. In addition, a number of glomerular alterations were present. These included capillary loop dilation, insudation of eosinophilic material, necrosis, duplication of the glomerular basement membrane, severe mesangiolysis with disruption of the mesangial matrix and segmental double-contours. The renal arterioles and interlobular arteries showed endothelial cell swelling. The subendothelial space was infiltrated by fibrinoid material and there was intensive fibrinoid necrosis of the wall of both arteries and arterioles extending into the glomerular tuft. These alterations were very similar to those observed in the hemolytic uremic syndrome. This observation suggests that the two injections of adriamycin, with a long interval in between them, might induce renal lesions similar to those observed in the hemolytic uremic syndrome.     

Behavioral compatibility and reproductive outcomes in two distant populations of captive brown-headed cowbirds (Molothrus ater).

Increased understanding of geographic variation in courtship behavior in animal species can provide insight into the ways behavior may influence evolutionary change. Here, the relationship of geographic variation in courtship behavior to reproductive outcomes was tested in two distant and behaviorally distinct populations of brown-headed cowbirds, Molothrus ater, by comparing rates of copulation and egg production. Females from an Indiana (IN) population and a South Dakota (SD) population were housed in aviaries with males from either their own population (INsame and SDsame) or the other population (INmix and SDmix). Over the breeding season, INsame females exhibited higher rates of copulation and egg production compared with INmix females, but no differences were detected between SDsame and SDmix females. The data suggest that behavioral differences between IN and SD cowbirds are the likely cause of lower egg production in the INmix females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biosystematic study of two populations of teleosts (Sardina pilchardus) and their copepod parasites (Peroderma cylindricum) from the Tunisian coast

The inability to achieve or maintain an erection of sufficient rigidity to perform sexual intercourse is a problem that affects between 10% and 20% of men at some time during their lives. Historically, the evaluation of impotence has been limited to history and psychological assessment. Nocturnal penile tumescence (NPT) monitoring is a procedure that can be used in the evaluation of impotence. Performed with appropriate measurement techniques and knowledge of the recording conditions and combined with a complete and accurate sexual history, NPT monitoring is the most effective noninvasive method of determining whether the underlying cause is organic or psychogenic.     

Physiological age of 2 populations of Anopheles (N.) albimanus Wied., 1821 (Diptera: Culicidae) and its importance in malaria transmission

The physiological age of Anopheles albimanus in two villages of Havana Province was studied. In general, we detected a similar pattern of behavior in the species, with a higher number of females being born during the dry season, which represents a higher risk of malaria transmission in this season.     

The importance of theory: Response to Brenner (2000).

L. Brenner's (see record 2000-02818-011) critique of I. Erev, T. S. Wallsten and D. V. Budescu (see record 1994-36026-001) focuses on their (a) use of a model to explain the paradox of the same data appearing to suggest over- and underconfidence, depending on how they are analyzed; (b) definitions of true judgment and error; and (c) specific use of judgments transformed to log-odds and a model formulated in those terms. The authors of the present article strongly disagree with the first point and discuss the importance of using models to interpret data. With regard to the second, the authors admit that the constructs of true judgment and error are poorly named but dispute L. Brenner's specific criticisms. Concerning the third, the authors had not claimed that the log-odds metric has any special status in judgment research and thus agree with L. Brenner's basic point. (PsycINFO Database Record (c) 2010 APA, all rights reserved)