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1.
The present investigation demonstrates the hepatoprotective potential of 50% ethanolic water extract of whole plant of Fumaria indica and its three fractions viz., hexane, chloroform and butanol against d-galactosamine induced hepatotoxicity in rats. The hepatoprotection was assessed in terms reduction in histological damage, changes in serum enzymes (SGOT, SGPT, ALP) and metabolites bilirubin, reduced glutathione (GSH) and lipid peroxidation (MDA content). Among fractions more than 90% protection was found with butanol fraction in which alkaloid protopine was quantified as highest i.e. about 0.2 mg/g by HPTLC. The isolated protopine in doses of 10–20 mg p.o. also proved equally effective hepatoprotectants as standard drug silymarine (single dose 25 mg p.o.). In general all treatments excluding hexane fraction proved hepatoprotective at par with silymarine (p0.01).  相似文献   

2.
The biomass of Corynebacterium glutamicum was treated with poly(amic acid) to improve the biosorption of Basic Blue 3 (BB3) from aqueous solution. The grafting of poly(amic acid) onto the biomass surface increased the density of the carboxyl groups. The UV-spectrum revealed that strong acidic (pH  2) and basic conditions (pH  11) resulted in the precipitation of BB3. Therefore, pH edge experiments were conducted only within the range 3–10; these results indicated that electrostatic attraction between carboxyl groups of C. glutamicum and BB3 dye cations was favored under alkaline conditions. From the Langmuir model, poly(amic acid)-modified biomass gave a maximum uptake of 173.6 mg/g at pH 9, compared to 52.8 mg/g by the raw biomass. The biosorption kinetics was found to be fast; with equilibrium attained within 10 min. The increase in the ionic strength strongly affected the uptake of BB3 for both forms of C. glutamicum.  相似文献   

3.
In France, whinchat Saxicola rubetra populations now rarely breed at altitudes below 1,000 m except in flooded alluvial plains. Whinchat reproductive success, the timing of haymaking and meadow bird density were assessed in 2003 in six areas selected in three different flooded plains, in five areas from two massifs at altitudes ranging from 990 to 1,250 m, and in 2004 in six areas of three flooded plains, in seven areas from three massifs at altitudes ranging from 1,200 to 2,000 m. The percentage of whinchat territories in which juveniles were observed was negatively correlated with mown areas at the time when 80% of hatched broods (observation of prey carryings by adults) would theoretically be fledged. Additionally, assessed hatching success was negatively correlated with early haymaking in 2003 and with meadow passerine territory density in 2004. In upland meadows, whinchat populations exhibited either low reproductive success and low density (1,200 m) or high reproductive success and high density (1,200 m). In lowland flooded meadow however, high density could match low reproductive success and whinchat population then acts as a sink population. We conclude that adequate agri-environmental policy should not focus only on lowland meadows, even if the highest meadow bird diversity is often found there.  相似文献   

4.
A study of temporal and spatial distribution of zooplankton frequently requires identification to species level. In such studies, samples are usually fixed, but according to different authors rotifer genera such as Synchaeta (Ehrenberg, 1832) can only be identified in live samples. A procedure for the identification of preserved specimens of Synchaeta is presented, permitting ecological studies without the examination of live material. Trophus morphology, investigated by light and scanning electron microscopy, was related to morphological characteristics of preserved specimens. In this way, body length was used to group formalin-preserved specimens into Synchaeta gr. tremula-oblonga sensu Ruttner-Kolisko (1974) (170 μm) or Synchaeta gr. stylata-pectinata sensu Ruttner-Kolisko (1974) (190 μm). Furthermore, body length, colour and shape were used to identify Synchaeta grandis (Zacharias, 1893), Synchaeta pectinata (Ehrenberg, 1832), Synchaeta kitina (Rousselet, 1902) and Synchaeta lakowitziana (Lucks, 1930). It was, however, impossible to distinguish Synchaeta tremula (Müller, 1786) from Synchaeta oblonga (Ehrenberg, 1832) by their trophi because of contradictions in the diagnostic keys and monographs regarding trophus morphology.  相似文献   

5.
In this study, the frontal plane moment arms of tibialis anterior (TA) and the lateral and medial heads of gastrocnemius (LG and MG) were determined using ultrasonography of ten healthy subjects. Analysis of variance was performed to investigate the effects of frontal plane angle, muscle activity, and plantarflexion angle on inversion–eversion moment arm for each muscle. The moment arms of each muscle were found to vary with frontal plane angle (all p<0.001). TA and LG exhibited eversion moment arms when the foot was everted, but MG was found to have a slight inversion moment arm in this position. As the ankle rotated from 0° to 20° inversion, the inversion moment arm of each increased, indicating that the three muscles became increasingly effective inverters. In neutral position, the inverter moment arm of MG was greater than that of LG (p=0.001). Muscle activity had a significant effect on both LG and MG moment arm at all frontal plane positions (all p0.005). These results demonstrate the manner in which frontal plane moment arms of gastrocnemius and TA differ across the frontal plane range of motion in healthy subjects. This method for assessing muscle action in vivo used in this study may prove useful for subject-specific planning of surgical treatments for frontal plane foot and ankle deformities.  相似文献   

6.
A series of azaterphenyl diamidines has been synthesized and evaluated for in vitro antiprotozoal activity against both Trypanosoma brucei rhodesiense (T. b. r.) and Plasmodium falciparum (P. f.) and in vivo efficacy in the STIB900 acute mouse model for T. b. r. Six of the 13 compounds showed IC50 values less than 7 nM against T. b. r. Twelve of those exhibited IC50 values less than 6 nM against P. f. and six of those showed IC50 values 0.6 nM, which are more than 25-fold as potent as furamidine. Moreover, two of them showed more than 40-fold selectivity for P. f. versus T. b. r. Three compounds 15b, 19d and 19e exhibited in vivo efficacy against T. b. r. much superior to furamidine, and equivalent to or better than azafuramidine. The antiparasitic activity of these diamidines depends on the ring nitrogen atom(s) location relative to the amidine groups and generally correlates with DNA binding affinity.  相似文献   

7.
NO is crucial for endothelial function and vascular health. Plasma nitrite (NO2) is the main oxidation product of NO and has been shown to reflect changes in eNOS activity. We hypothesized that plasma NO2 response to physical exercise stress along with physiological endothelial function would be reduced with increasing severity of vascular disease. Subject groups were: (a) risk factors but no vascular disease (RF); (b) Type 2 diabetes with no vascular disease (DM); (c) diagnosed peripheral arterial disease (PAD); and (d) DM + PAD. Venous blood was drawn at rest and 10 min following maximal exercise. Plasma samples were analyzed by reductive chemiluminescence. Brachial diameters were imaged prior to, during and following 5 min of forearm occlusion (BAFMD). There were no differences in resting plasma NO2 or BA diameters between groups. The PAD groups had lower age adjusted BAFMD responses (p  0.05). Within group analysis revealed an increase in NO2 in the RF group (+39.3%), no change in the DM (−15.51%), and a decrease in the PAD (−44.20%) and PAD + DM (−39.95%). This was maintained after adjusting for age and VO2peak (p  0.05). ΔNO2 and BAFMD were the strongest independent predictors of VO2peak in multivariate linear regression. These findings suggest ΔNO2 discriminates severity of cardiovascular disease risk, is related to endothelial function and predicts exercise capacity.  相似文献   

8.
Canna indica L. is an upright perennial rhizomatous herb, and Schoenoplectus validus (Vahl) A. Löve and D. Löve is a tall, perennial, herbaceous sedge. The nutrient uptake kinetics of C. indica and S. validus were investigated using the modified depletion method after plants were grown for 4 weeks in simulated secondary-treated wastewater. The maximum uptake rate (Imax) and Michaelis–Menten constant (Km) were estimated by iterative curve fitting. The Imax for NH4N (623 μmol g−1 dry root weight h−1) was significantly higher than that for NO3N (338 μmol g−1 dry root weight h−1) in S. validus. In contrast, no difference was observed in C. indica. The Imax values for NO3N and NH4N were higher in S. validus than in C. indica. A significantly lower Km was detected for NO3N uptake in C. indica (385 μmol L−1) compared to that in S. validus (1908 μmol L−1). The Imax for PO4P did not differ between the plant species. The Km for PO4P was significantly higher in C. indica (157 μmol L−1) than in S. validus (60 μmol L−1). In conclusion, we found that S. validus preferred NH4N over NO3N, had greater capacity for N uptake and higher affinity for PO4P, but C. indica had greater affinity for NO3N. Nutrient uptake capacity is likely related to habitat preference, and is influenced by the structure of roots and rhizomes.  相似文献   

9.
Wang Y  Liu Y  Han R  Yang J  Zhu Z  Zhang Y  Yao Z  Gao W  Shen Z 《Cytokine》2008,41(3):240-243
Aim: The aim of this study was to analyze the expression levels of plasma soluble Fas (sFas) and soluble Fas ligand (sFasL) in patients with orthotopic liver transplantation (OLT) procedures routinely performed without venovenous bypass. Methods: The sFas and sFasL were analyzed in the blood of 20 consecutive patients who underwent transplantation. Blood samples were drawn from the radial artery at serial time points before, during, and after surgery. Plasma levels of sFas and sFasL were detected by Enzyme Linked-Immuno-Sorbent Assay. Plasma aspartate transaminase (AST) and alanine transaminase (ALT) were assayed by routine clinical chemistry testing. Results: Marked elevation of plasma AST and ALT were detected at the reperfusion and postoperation time points (P < 0.001), with a peak on the first postoperative day. The mean plasma concentration of sFas and sFasL remained unchanged from preoperative to anhepatic phase (T1 to T3) (P  0.268). The sFas and sFasL concentrations were significantly higher at 15 and 60 min after reperfusion compared to the preoperative value (P  0.048). Postoperatively, sFas and sFasL concentration were decreased to preoperative levels on the first postoperative day (P  0.127). Conclusion: The sFas and sFasL seem to be involved in reperfusion injury during OLT. The understanding of Fas may provide new insights into the mechanisms of ischemia/reperfusion injury during OLT.  相似文献   

10.
Microbial reduction of soluble uranyl [U (VI)] to insoluble uraninite by sulfate reducing bacteria (SRB) is a promising remediation strategy for uranium-contaminated groundwater. Effects of environmental factors, including pH and coexisting ions, on U (VI) bioreduction processes (UBP) remain unknown. Anaerobic batch experiments were performed to evaluate impact on UBP. Kinetic investigations with varied pH demonstrated that U (VI) was reduced mostly within 48 h. The bioprecipitation yields depended strongly on pH, increasing from 12.9% to 99.4% at pH 2.0 and 6.0, respectively. Sulfate concentration 4000 mg l−1 did not affect UBP; however, sulfate concentration 5000 mg l−1 significantly slowed UBP. Biogenic H2S produced during sulfate reduction was not directly involved in UBP. At 20 mg l−1 Zn or 10 mg l−1 Cu, no UBP inhibition was observed and uraninite was detected in metal sulfide precipitate. However, 25 mg l−1 Zn or 15 mg l−1 Cu stopped UBP completely. Cu toxicity mechanism probably differed from Zn. The ability to reduce U (VI) was lost permanently with exposure to 15 mg l−1 Cu, but not for Zn 25 mg l−1. No uraninite could be detected before nitrate removal, suggesting nitrate strongly inhibited UBP, which may possibly be related to denitrification intermediates controlling the solution redox potential.  相似文献   

11.
Coffee leafminer, Leucoptera coffeella, is a pest in many New World coffee growing areas. Previous studies suggested that its population dynamics were strongly affected by natural enemies, particularly of larvae, and physical environmental conditions. Our study documented through field surveys and life table analyses (i) the natural enemy complex associated with coffee leafminer and (ii) the impacts of natural enemies on the population dynamics of coffee leafminer, on coffee (Coffea arabica) at two elevations and two rainfall levels in the Soconusco region of Chiapas, Mexico. Twenty-two larval parasitoid species (including 14 morphospecies) were collected. Egg and pupal parasitoids were not recovered. Life table analyses showed that parasitism contributed 10% of real mortality, and parasitism rates were 8–10-fold higher at the low (<550 m) versus high (>950 m) elevation; parasitism rates were similar under low (<100 mm) and high (>400 mm) rainfall. Seventeen predator species (including five morphospecies) were collected, of which most were ants (Formicidae, 14 species) that contributed >58% of real mortality. Life table analyses showed that predation rates were higher at high versus low elevation and under high versus low rainfall. Independently of elevation and rainfall, egg predation (likely by ants) was the most important source of indispensable mortality (range = 0.13–0.30), except at low elevation and high rainfall where pupal predation (=0.14) was similarly important. Also, predation was the main source of coffee leafminer larval and pupal mortality during a 13-month period in a low elevation coffee farm and was highest during the rainy season (>400 mm rainfall/month), when coffee leafminer prevalence was highest. Overall, predation of eggs and pupae (the latter particularly at low elevation), mostly by ants, were the most important sources of coffee leafminer mortality. Because ants were the main source of coffee leafminer egg and pupal mortality, their importance and potential role in coffee pest management strategies were discussed.  相似文献   

12.
We studied the seasonal variation on aerobic metabolism and the response of oxidative stress parameters in the digestive glands of the subpolar limpet Nacella (P.) magellanica. Sampling was carried out from July (winter) 2002 to July 2003 in Beagle Channel, Tierra del Fuego, Argentina. Whole animal respiration rates increased in early spring as the animals spawned and remained elevated throughout summer and fall (winter: 0.09 ± 0.02 μmol O2 h− 1 g− 1; summer: 0.31 ± 0.06 μmol O2 h− 1 g− 1). Oxidative stress was assessed at the hydrophilic level as the ascorbyl radical content / ascorbate content ratio (A / AH). The A / AH ratio showed minimum values in winter (3.7 ± 0.2 10− 5 AU) and increased in summer (18 ± 5 10− 5 AU). A similar pattern was observed for lipid radical content (122 ± 29 pmol mg− 1 fresh mass [FW] in winter and 314 ± 45 pmol mg− 1 FW in summer), iron content (0.99 ± 0.07 and 2.7 ± 0.6 nmol mg− 1 FW in winter and summer, respectively) and catalase activity (2.9 ± 0.2 and 7 ± 1 U mg− 1 FW in winter and summer, respectively). Since nitrogen derived radicals are thought to be critically involved in oxidative metabolism in cells, nitric oxide content was measured and a significant difference in the content of the Fe–MGD–NO adduct in digestive glands from winter and summer animals was observed. Together, the data indicate that both oxygen and nitrogen radical generation rates in N. (P.) magellanica are strongly dependent on season.  相似文献   

13.
The effect of reduced application rate, soil temperature at shallow depth (2.5 cm), and soil type on the efficacy of Steinernema carpocapsae against the navel orangeworm, Amyelois transitella, was evaluated in six field trials employing 1 m2 plots conducted from November 2003 through December 2004 in Madera and Kern Counties, California. Nematodes were applied at a concentration of 100,000 infective juveniles (IJs)/m2 (109/ha) in a volume of 187 ml water/m2 (1870 L/ha) with a post-application irrigation in all trials. Mortality ranged from 7.9 to 64.9% in successful trials and percent reduction in live larvae per plot was as high as 74.6%. Percent reduction and mortality were highly correlated (r2 = 0.78) and larval reduction typically was 10–11% greater than mortality for any treatment. In one trial, although nematode treatment significantly increased mortality compared to the controls, the treatment was deemed unsatisfactory because mortality was <15%. Soil temperature in this trial rose to 39 °C within 5 h after application. Nematodes failed in two other trials when soil temperature fell below freezing (minimum temperatures −3.0, −5.5 °C, respectively) several times in a 5-day period. We conclude that a commercially feasible application volume of 1870 L water/ha followed by post-application irrigation at this same rate was effective, and that soil maximum temperature at or below 32 °C during the first 24 h after application is necessary for treatment success.  相似文献   

14.
Superoxide dismutase (SOD) catalyzes the conversion of the superoxide radical (O2) into oxygen and hydrogen peroxide. Deschampsia antarctica is a plant that grows in Antarctica and survives to extreme low temperature and high UV radiation, thus it is an ideal model to study novel antioxidants. A cDNA Cu/Zn-SOD gene from D. antarctica was cloned into a pET vector and expressed in Escherichia coli BL21-SI. 112 mg/L of recombinant Cu/Zn-SOD was attained in batch cultures in bioreactor. Using Ni-affinity gel chromatography, the recombinant Cu/Zn-SOD was recovered with a purity of 90% and a specific enzyme activity of 749 at 25 °C. However, zymogram test showed that the enzyme has more activity at 4 °C. This D. antarctica SOD could be used to reduce the oxidation of refrigerated and frozen foods.  相似文献   

15.
Fallen timber is an important component of many aquatic and terrestrial ecosystems around much of the world. Its distribution and abundance has been extensively altered, especially over the past 200 years. While correlative evidence suggests that many species require fallen timber for them to occupy locations, there are few precisely controlled field experiments that show conclusively how species respond to variation in loads. We manipulated wood loads (ranging from 0 to 80 Mg ha−1) and monitored the response over 6 years of a species of marsupial, the yellow-footed antechinus Antechinus flavipes. The antechinus appeared to prefer locations having fallen-timber loads 20 Mg ha−1. Antechinuses avoided bare areas (i.e. 0 Mg ha−1) and areas having finer forms of woody material. Changes in densities of the antechinus in excess of those occurring in the control plots were clear after 2 years following manipulation of loads, and were even more pronounced after almost 6 years. Therefore, we are confident that higher loads are favoured by the antechinuses. There was no evidence of breeding success by females in sites with 20 Mg ha−1, and that the highest, consistent breeding activity was achieved at sites with the greatest fallen-timber loads (80 Mg ha−1). Our results, which experimentally were designed to address responses to fallen-timber loads, were complicated by perturbations caused by managed flooding episodes of the experimental area. Flooding appears to lead to population booms of the antechinus, most probably related to irruptions of prey species such as carabid beetles and wolf spiders, which are large-bodied and are prey for the antechinus. Nevertheless, we show that there are differences in densities in different wood-load treatments even against a background of boom-and-bust dynamics associated with flooding.  相似文献   

16.
A batch sorption technique was used to study the biosorption of Pb2+, Cd2+ and Zn2+ ions onto the vastly abundant water hyacinth weed, Eichhornia crassipes biomass in binary and ternary systems at a temperature of 30 °C and pH 4.84. Mutual interference effects were probed using equilibrium adsorption capacity ratios, , where the prime indicates the presence of one or two other metal ions. The combined action of the metals was found to be antagonistic, and the metal sorption followed the order Pb2+  Cd2+  Zn2+. The behaviour of competitive biosorption for Pb–Cd and Pb–Zn combinations were successfully described by the Langmuir Competitive Model (CLM), whilst the model showed poor fitting to the Cd–Zn data. In conclusion, Pb2+ ions could still be effectively removed from aqueous solution in the presence of both Cd2+ and Zn2+ ions, but removal of the Cd2+ and Zn2+ ions would be suppressed in the presence of Pb2+.  相似文献   

17.
Neutral trehalase from Neurospora crassa was expressed in Escherichia coli as a polypeptide of 84 kDa in agreement with the theoretical size calculated from the corresponding cDNA. The recombinant neutral trehalase, purified by affinity chromatography exhibited a specific activity of 80–150 mU/mg protein. Optima of pH and temperature were 7.0 and 30 °C, respectively. The enzyme was absolutely specific for trehalose, and was quite sensitive to incubation at 40 °C. The recombinant enzyme was totally dependent on calcium, and was inhibited by ATP, copper, silver, aluminium and cobalt. KM was 42 mM, and Vmax was 30.6 nmol of glucose/min. The recombinant protein was phosphorylated by cAMP-dependent protein kinase, but not significantly activated. Immunoblotting with polyclonal antiserum prepared against the recombinant protein showed that neutral trehalase protein levels increased during exponential phase of N. crassa growth and dropped at the stationary phase. This is the first report of a neutral trehalase produced in E. coli with similar biochemical properties described for fungi native neutral trehalases, including calcium-dependence.  相似文献   

18.
The haemolymph lipoprotein of the scorpion, Pandinus imperator was isolated and characterised. Contrary to the lipoproteins of insects and the discoidal HDL-lipoproteins of a crayfish and polychaete, the Pandinus lipoprotein consists of three instead of two apoproteins (apoPiLp I = 230 kDa, apoPiLp II = 130 kDa and apoPiLp III = 120 kDa). The apolipoproteins are arranged in varying stoichiometries as judged by cross-linking experiments. In lipoprotein samples from individual animals, the two smaller subunits occurred in a 1:1 stoichiometry, while the relative amount of the 230 kDa peptide varied. The lipoprotein is a slightly heart-shaped HDL with a diameter of 15 nm. It is present in two densities of 1100 and 1190 kg/m3, of which the latter is by far more abundant. The native molecular mass was estimated to be 500 kDa. The lipid content was determined as 33.5% and consists of 70% neutral lipids and 30% phospholipids. Strikingly, 42.5% of the phospholipids is phosphatidylserine while phosphatidylcholine and phosphatidylethanolamine account for 55.1% and 2.3%, respectively. Carbohydrate analysis suggests the presence of only high-mannose-type N-glycans. N-glycan profiling shows glycans corresponding to a size of 8.0–11.5 hexose units.  相似文献   

19.
The granulovirus infecting the potato tuber moth (PoGV) is an important biocontrol agent, especially for managing the pest in rustic potato storerooms. For efficient propagation and use of baculoviruses in pest control strategies, information on the effects of temperature on virus multiplication and activity is crucial. The interaction between PoGV infection and incubation temperature on P. operculella was studied in laboratory bioassays by determining the survival, yield of virus-infected larvae, and the kinetics of virus in vivo increase. Bioassays for LC50 determination by using the egg-dip method were repeated over a period of six years in controlled incubation chambers at six constant temperatures ranging from 16 to 28 °C. Additionally, at temperatures of 17 and 24 °C the kinetics of virus development and increase in larva were assessed in destructive time-series experiments. Three different virus concentrations were used for inoculation. Control mortality was significantly temperature-dependent and was well described by a second-order polynomial function, with lowest mortality at 25 °C (20%) and highest at 16 °C (>60%). LC50 values and slopes of probit-mortality curves were not significantly different between temperatures. Numbers of virus-infected larvae increased exponentially with increasing log-concentration of virus inoculum; an effect of temperature was not evident. Virus granules per larva correlated highly with larval age and larval weight. Multiple regression revealed minor direct effects of temperature on virus numbers; however, with decreasing temperature, larval weight and hence virus numbers increased. As a result, temperature is an important factor to be considered in virus-production facilities. Rearing temperature in virus-production facilities should be maintained at temperatures around 24 °C.  相似文献   

20.
A correlation between foraminiferal community dynamics and environmental conditions may provide a basis for establishing paleoclimatic proxies. We studied planktic foraminiferal shell fluxes and assemblages in samples collected in three time-series sediment trap deployments in the western equatorial Pacific under La Niña conditions from January to November 1999. Eleven species contributed about 90% of the total flux in all traps. Two sites (MT1, MT3) in the Western Pacific Warm Pool region (WPWP) were characterized by common occurrences of the species Globigerinoides ruber, Globigerinoides sacculifer, Globigerinoides tenellus, and Neogloboquadrina dutertrei. Site MT5 farther to the east in the equatorial upwelling region had common occurrences of Globigerina bulloides, Globigerinita glutinata, and Pulleniatina obliquiloculata. Very high abundances of G. bulloides and G. glutinata at MT5 indicate that equatorial upwelling (EU) occurred during the 1999 La Niña. The two western sites have similar assemblage compositions, but MT1 ( 135°E) has the highest fluxes (up to  3800 tests m− 2 day− 1), whereas MT3 ( 145° E) has fluxes below  2200 tests m− 2 day− 1. Relatively high fluxes (up to  3000 tests m− 2 day− 1) occur at site MT5 ( 176° E), where upwelling occurred.The differences in faunal composition in the WPWP and EU might be attributable to differences in the way in which nutrients are supplied to the phytoplankton: large amounts of suspended material are supplied to the WPWP by advection of waters passing through the coastal region of an archipelago, whereas upwelling of nutrient-rich waters enhances primary production in the EU. At the westernmost site in the WPWP, a peak in the G. bulloides flux coincided with southward flow of the New Guinea Coastal Current (NGCC) in late February, but the highest G. ruber flux coincided with northward flow of this current in late May. Thus, the differences in species dominance at this location may be caused by monsoon-driven variability in the flow direction of the NGGC.  相似文献   

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