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1.
The 24-h median lethal concentrations of pentachlorophenol to Chironomus plumousus, Tubifex sinicus and Galba pervia were 0.302, 0.977 and 0.293 mg/L, respectively. Bioconcentration factors of C. plumousus, T. sinicus and G. pervia to pentachlorophenol were 108, 367 and 85 at 0.02 mg/L pentachlorophenol, respectively. As pentachlorophenol concentration increased, the G. pervia egg hatching rates became lower, and the total hatched time became longer. Pentachlorophenol teratogenesis was demonstrated by observing the deformation of C. plumousus larvae mentum.  相似文献   

2.
Chirality in pesticides has become a challenge because of enantiomers’ different toxicities to non-target organisms. Acute and chronic toxicities of Rac-metalaxyl and R-metalaxyl to Daphnia magna were determined and compared. The 48-h LC50 for Rac- and R-metalaxyl to Daphnia magna were 51.5 and 41.9 mg/L. In a 14-day chronic test, the lowest-observed-effective concentration (LOEC) and no-observed-effective concentration (NOEC) of Rac-metalaxyl were 2 and 1 mg/L, respectively, whereas those of R-metalaxyl were 1 and 0.1 mg/L. Body length, days-to-first-brood and number of broods per female were significantly (p < 0.05) affected by R-metalaxyl at >1.0 mg/L, but affected by Rac-metalaxyl at ≥2.0 mg/L.  相似文献   

3.
Objectives The objective of this study is to optimize the evaluation of the exposure to N,N-dimethylformamide (DMF) in synthetic leather factories by diffusive samplers. The DMF exposure was monitored in synthetic leather factories by two sampler types: active and diffusive. Methods Air measurements were carried out using two different personal air samplers, a diffusive and an active one. The diffusive sampling method, TK200 with charcoal filters, was examined in comparison with pumping through NIOSH silica gel tubes workplace air as with the currently available “gold standard”. The evaluation was carried out, in two different years but in the same season, for all the duration of the shift, i.e. 8 h on workers employed in five different factories in the district of Florence and Prato (Italy). Results The statistical and graphical analysis of data show a good correlation between active and passive samplers (r = 0.96, P < 0.001, n = 91), a good linear regression (DMFdiffusive = 0.95 DMFactive + 0.15, R 2 = 0.92), a not statistically significant difference between data (tested by paired t test and non-parametric Wilcoxon test). Moreover, all these results are confirmed for data lower and higher than TLV-TWA, in particular we found a significant Pearson correlation (r = 0.92, P < 0.001, n = 83; r = 0.92, P < 0.05, n = 8, respectively) and a significant linear regression (DMFdiffusive = 0.88 DMFactive + 0.73, R 2 = 0.86; DMFdiffusive = 0.90 DMFactive + 3.76, R 2 = 0.85). Besides, the analysis of graphical representations confirmed the previous evidences. Finally, we can not find a significant difference between different types of job. Conclusions Due to the good agreement between the two groups of data, the TK200 samplers can be considered as a simpler approach than the pump for screening worker exposures to DMF.  相似文献   

4.
Most chemical carcinogens are metabolized and activated in vivo by phase I enzymes including the microsomal cytochromes P450 and epoxide hydroxylases. The carcinogens and their metabolites are detoxified by phase II enzymes that in clude various transferases such as glutathion-S-transferases (GST). Increasing numbers of studies have demonstrated the association of the polymorphisms inGSTM1 (a member of GST) andCYP1A1 genes with the susceptibility to lung cancer. Subsequently, the polymorphisms appear to be important biomarkers that provide information for assessment of exposure and total burden of environmental carcinogens. Therefore, the investigation of the polymorphisms in these genes will provide information not only for the prediction of individual cancer risk but also for the prevention of cancer. In this review, we will summarize the polymorphisms in theGSTM1 andCYP1A1 genes and their relation to lung cancer susceptibility.  相似文献   

5.
Studies were carried out to determine the toxicity of some selected pesticides on fresh water fish in a tropical environment. The uptake of the pesticides lindane, pentachlorophenol (PCP), and propoxur, which are frequently used on farms, and in industries as well as by loggers and timber men on wood were studied in concrete ponds at the University of Cape Coast, in Ghana. The fish used for the study were Oreochromis niloticus, Clarias gariepinus, and Chrysicthys nigrodigitatus. They were obtained from cultured ponds in the Cape Coast and Mankessim districts in the Central Region and Weija Dam, in the Greater Accra region of Ghana. Single high lethal concentration (SD) or acute treatment and cumulative/chronic (or multiple minor) lethal concentration (CD) treatment were employed in administering the pesticides to the fish via water. Gas chromatograph electron capture detector analysis was done on the dead fish to see the extent of ingestion. The LC50 values obtained for lindane on the three fish samples were as follows: Chrysicthys – 0.38 mg L−1; Oreochromis – 0.42 mg L−1, and Clarias – 1.2 mg L−1. Mortalities occurred in fish within 3–5 days of application. For the PCP on Chrysicthys, Oreochromis, and Clarias species the LC50 values were 0.42, 0.32 and 0.64 mg L−1, respectively, for over a 2- to 3-day period. For a three-time influx period of propoxur the LC50 for Chrysicthys, Oreochromis, and Clarias, were 22.0, 30.40, and 45.04 (all in mg L−1), respectively. The results obtained indicated that the pesticides had adverse effects on the general growth and reproduction of fish as shown by gonadosomatic indices.  相似文献   

6.
Objectives To investigate the relationship between N,N-dimethylformamide (DMF) exposure and excretion of urinary N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) and N-methylformamide (NMF) in workers at synthetic leather manufacturing factories in Korea, for the first time.Methods One-hundred forty-four male workers at nine synthetic leather manufacturing factories were surveyed. Exposure to DMF was evaluated through breathing zone air sampling followed by analysis via a gas chromatograph equipped with a flame ionization detector (GC-FID). The levels of NMF and AMCC were determined by a GC with a flame thermionic detector (GC-FTD). Urine samples were collected at the end of the workshift.Results and Conclusions Geometric mean of workplace air DMF and urinary NMF was 8.8 ppm and 47.5 mg/l, respectively, and the level of DMF and NMF was significantly correlated. The biological exposure limit for NMF (15 mg/ml) was exceeded in 89.5% of urine samples, and 37.9% of air samples exceeded the environmental DMF exposure limit (10 ppm), indicating a serious health risk to the employees of the synthetic leather industry in Korea. Exposure to 10 ppm DMF in the workplace air corresponded to a urinary NMF concentration of 53.4 mg/l. Alcohol intake the day before urine was sampled influenced NMF excretion into urine (40.5 mg/l NMF for the no-alcohol group and 94.6 mg/l for the group consuming more than 63.0 g alcohol/day). We could not find a significant relationship between air DMF and urinary AMCC concentration. Exposure to 10 ppm DMF corresponded to an AMCC concentration of 8.0 mg/l in the urine samples collected on the same day as the air was sampled.  相似文献   

7.
Removal of phosphorus and nitrogen from eutrophicated water was carried out by in situ bioremediation. With the addition of Acinetobacter calcoaceticus, 65.0% ± 4.0% of total phosphorus (TP), 37.0% ± 4.0% of total nitrogen (TN), 75.0% ± 7.0% nitrite (NO2 –N), and 87.0% ± 4.0% of ammonia (NH4 +–N) were removed. Furthermore, chlorophyll a removal in the inoculated treatments reached 83.7% ± 1.5%, and algae in the water was basically controlled.  相似文献   

8.
The integrated toxicities of 4-tert-octylphenol (t-OP) on Siganus oramin were investigated by dietary administration at doses of 5, 25 and 125 mg/kg body weight over 28 days. Significant increase was observed in the activity of hepatic glutathione S-transferase at 125 mg/kg on both day 14 and 28 in males, and at all doses on day 28 in females, and in hepatosomatic index at 25 mg/kg on day 14 in both sexes. Plasma levels of testosterone and cortisol decreased significantly at all doses on day 28. Histopathologic changes in liver, spleen, intestine and testis deteriorated with increasing doses and duration. The results suggest that S. oramin is sensitive to t-OP, and the above endpoints may be potential biomarkers for evaluating toxicities of environmental pollutants such as t-OP.  相似文献   

9.
We investigated the effects of three different pesticides (carbendazim, dimethoate, and glyphosate) and their mixture on the growth and reproduction of the earthworm species, Eisenia fetida. The study was conducted following the suggestion of the International Workshop on Earthworm Ecotoxicology. The results showed that the pesticide treatment had a marked negative impact on the growth and reproduction of earthworms. Carbendazim and dimethoate were found to cause greater harm to the selected earthworm species than glyphosate.  相似文献   

10.
We examined the selective inhibitory potential of rice hull extract on the toxic cyanobacterium Microcystis aeruginosa, in comparison with inhibitory effects on two green algae (Ankistrodesmus convolutus and Scenedesmus quadricauda) and a zooplankton (Daphnia magna) species. The inhibitory effect of rice hull extract, measured by algal growth or zooplankton survival using four different concentrations of extract (1, 10, 100 and 1000 μg L−1), was highest on Microcystis strains (average: 98%, range: 95%–99%), followed by D. magna (average: 22%, range: 10%–47%), A. convolutus (average: 20%, range: 16%–24%), and S. quadricauda (average: 8%, range: 0%–15%). Rice hull extract had only a small effect on the growth of the green algae and Daphnia, particularly in the range 1–100 μg L−1, and the inhibitory effect was somewhat diminished even at the 1,000 μg L−1 level, at the end of the experimental period, especially for Daphnia. Our study indicates that rice hull extract has a strong specific algicide potential when used to combat M. aeruginosa.  相似文献   

11.
North Atlantic culture lacks a commonly shared view on dying well that helps the dying, their social environment and caregivers to determine their place and role, interpret death and deal with the process of ethical deliberation. What is lacking nowadays, however, has been part of Western culture in medieval times and was known as the ars moriendi (art of dying well) tradition. In this paper an updated version of this tradition is presented that meets the demands of present day secularized and multiform society. Five themes are central to the new art of dying: autonomy and the self, pain control and medical intervention, attachment and relations, life balance and guilt, death and afterlife. The importance of retrieving the ancient ars moriendi outreaches the boundaries of palliative medicine, since it deals with issues that play a central role in every context of medical intervention and treatment.  相似文献   

12.
Polyethoxylated tallowamine (POEA) is a non-ionic surfactant used in many herbicide formulations to increase the ability of active ingredients to penetrate leaf cuticles. However, it has also been shown to disrupt respiratory membranes in aquatic organisms. In this study, Daphnia magna was used to examine the lethal and sub-lethal toxicity of three POEA formulations consisting of 5:1, 10:1, and 15:1 average oxide:tallowamine. The formulation consisting of 10:1 was the most acutely toxic with a 48-h LC50 value of 97.0 μg/L and 15:1 was least toxic at 849.4 μg/L. All formulations inhibited growth at concentrations between 100 and 500 μg/L.  相似文献   

13.
Three phenolic compounds were evaluated for their toxicity to the freshwater species Pimephales promelas (fathead minnow) and Ceriodaphnia dubia. Acute toxicity tests using nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), and nonylphenol diethoxylate (NP2EO) were conducted using the single chemicals and as binary and tertiary mixtures. These compounds frequently coexist in surface waters as the result of discharges from wastewater treatment plants that are inefficient at removing nonylphenolic compounds. The mean lethal concentrations (LC50s) for NP, NP1EO, and NP2EO to the fathead minnow were 136, 218, and 323 μg/L, respectively. The LC50s of NP, NP1EO, and NP2EO to C. dubia were 92.4, 328, and 716 μg/L, respectively. The degree of toxic interactions was evaluated by converting mixture LC50 estimates to toxic units (TUs). When exposed to fathead minnows, the binary mixtures of NP plus NP1EO and NP plus NP2EO produced 0.87 and 0.70 TUs, respectively. The tertiary mixture for the same species produced a TU of 0.86. When exposed to C. dubia, the binary mixtures of NP plus NP1EO and NP plus NP2EO produced 0.48 and 1.12 TUs, respectively, whereas the tertiary mixture gave a TU of 0.90. This research suggests that the compounds are additive or synergistic when present in mixtures.  相似文献   

14.
Background/Aim of the study  This study evaluates the effects of the blue green alga spirulina as the sole dietary source of protein on muscle protein in weaning rats. Methods  Young (30 days) Wistar rats were fed, during 60 days, with 17% protein spirulina (S) and compared to rats fed 17% protein casein (C). We evaluated the muscle total protein and DNA contents and the in vitro protein synthesis and degradation rates as well the myosin protein expression. Results  The groups presented similar body weight (C = 427.3 ± 8.6; S = 434.6 ± 7.7 g) and length (C = 25.4 ± 0.2; S = 25.6 ± 0.2 cm). Soleus muscle total protein (C = 2.9 ± 0.1; S = 2.7 ± 0.1 mg/100 mg) and DNA (C = 0.084 ± 0.005; S = 0.074 ± 0.005 mg/100 mg) contents were also similar in both groups. Protein degradation (C = 427.5 ± 40.6; S = 476.7 ± 50.5 pmol/mg−1 h−1) did not differ between the groups but protein synthesis (C = 17.5 ± 1.0; S = 25.2 ± 1.9 pmol/mg−1 h−1) and myosin content (western blot analyses) were higher (P < 0.05, t test) in spirulina group. Conclusions  Although the spirulina proved adequate protein quality to maintain body growth, the muscle protein synthesis rates were increased by the ingestion of the experimental diet in young rats.  相似文献   

15.
A copper-resistant bacteria CCNWSX2332 was isolated from root nodules of Lespedeza cuneata growing in a gold mining tailing region in northwest of China. The specific growth rate of the strain was 0.62 μh−1 in the presence of 2.0 mM Cu2+ in TY liquid media, and the maximum copper accumulation of whole cell reached 147.03 μM Cu2+ per gram (dry weight) after 4 h incubation. A partial sequence of the copper resistance gene copA was amplified from the strain, and the phylogenetic analysis based on 16S rDNA sequence showed that CCNWSX2332 belonged to Agrobacterium, and it had 100% similarity with Agrobacterium tumefaciens type strain IAM13129T.  相似文献   

16.
The purpose of this article was to establish a simple residue analysis method for S-metolachlor in maize and to study its dissipation and residue in maize field eco-system. The results showed that S-metolachlor declined rapidly in maize seedling and soil after application. The half-lives of S-metolachlor in maize seedlings in Beijing and Changchun were 6.68 and 4.85 days, respectively, and in soil were 12.81 and 14.81 days, respectively. The terminal residues of S-metolachlor in soil samples were very low (around 0.005-0.045 mg/kg), and the residues in maize seeds were not detectable. The use of S-metolachlor according to the recommended dosages in maize could be considered safe.  相似文献   

17.
Inter-individual variability in drug response is well known. Genetic polymorphism in genes encoding drug-metabolizing enzymes results in variation in drug metabolism and in turn drug response. The cytochrome P450 enzymes (CYP) play a central role in the metabolism of many therapeutic agents. CYP2C19 gene polymorphism is widely studied in Caucasians, African, and Oriental populations; however, far less is known about other ethnic groups such as Indians. Indian population is an inter-mixture of the Aryan, Dravidian, Kolarain, and the Mongoloid races. CYP2C19 gene polymorphism is reported in North Indian and South Indian populations yet not much is known about Maharashtrian population of Australoid-Europoid origin residing in Western India. This is the first report on CYP2C19 allele and genotype frequencies in Maharashtrian population. In this study, genotypes of major allelic variants of CYP2C19 gene in 139 unrelated healthy Maharashtrian subjects was determined and their frequencies were compared with previously studied Indian and other populations. Meta-analysis revealed that the study population is distinct from Caucasians, Africans and some of the Asian populations and significant heterogeneity exists among Indian subpopulations.  相似文献   

18.
Chlamydia pneumoniae has been linked with increased risk of cardiovascular disease, but data on stroke are sparse. We examined whether seropositivity to Chlamydia pneumoniae was associated with the risk of ischemic stroke in a nested case–control study. Data on Chlamydia pneumoniae serology, lifestyle factors, and medical history were obtained at baseline. Verified cases (n = 254) were compared with gender- and age-matched controls (n = 254). Positive IgA ( 1:16) or IgG ( 1:64) titers were associated with an increased risk of acute ischemic stroke, i.e. adjusted odds ratios (ORs) were 1.54 (95% confidence interval, CI: 0.96–2.47) and 1.28 (95% CI: 0.83–1.95). The adjusted OR was 1.77 (95% CI: 1.04–3.00) when both titers were elevated. The highest point estimates were seen for ischemic stroke due to large-artery atherosclerosis, adjusted OR: 6.32 (95% CI: 0.76–52.61) (IgG ( 1:64)). No clear associations were found for other types of ischemic stroke. The strength of the association varied depending on gender and the chosen cut-off values for the antibody titers. These results partly support the hypothesis that serologic evidence of Chlamydia pneumoniae infection may be associated with an increased risk of ischemic stroke. However, the risk may differ according to gender, subtype of ischemic stroke, and cut-off value of antibody titers.  相似文献   

19.
The term pedophilia denotes the erotic preference for prepubescent children. The term hebephilia has been proposed to denote the erotic preference for pubescent children (roughly, ages 11 or 12–14), but it has not become widely used. The present study sought to validate the concept of hebephilia by examining the agreement between self-reported sexual interests and objectively recorded penile responses in the laboratory. The participants were 881 men who were referred for clinical assessment because of paraphilic, criminal, or otherwise problematic sexual behavior. Within-group comparisons showed that men who verbally reported maximum sexual attraction to pubescent children had greater penile responses to depictions of pubescent children than to depictions of younger or older persons. Between-groups comparisons showed that penile responding distinguished such men from those who reported maximum attraction to prepubescent children and from those who reported maximum attraction to fully grown persons. These results indicated that hebephilia exists as a discriminable erotic age-preference. The authors recommend various ways in which the DSM might be altered to accommodate the present findings. One possibility would be to replace the diagnosis of Pedophilia with Pedohebephilia and allow the clinician to specify one of three subtypes: Sexually Attracted to Children Younger than 11 (Pedophilic Type), Sexually Attracted to Children Age 11–14 (Hebephilic Type), or Sexually Attracted to Both (Pedohebephilic Type). We further recommend that the DSM-V encourage users to record the typical age of children who most attract the patient sexually as well as the gender of children who most attract the patient sexually.  相似文献   

20.
Objectives: A cross-sectional survey was performed to evaluate the association between H. pylori and adult height. Methods: H. pylori infection was assessed using a 13C-urea breath test and height measured by a research nurse using a stadiometer in participants between the ages of 40–49 years. Results: Height was measured in 2932/3682 participants that attended and were evaluable. H. pylori infected women were 1.4 cm shorter than uninfected women (95% confidence interval, CI=0.7–2.1 cm) and this statistically significant difference persisted after adjusting for age, ethnicity, childhood and present socio-economic status (H. pylori positives 0.79 cm shorter; 95%CI: 0.05–1.52 cm). H. pylori positive men were 0.7 cm shorter than uninfected men but this did not reach statistical significance (95% CI: −0.1–1.5 cm). Conclusion: Although H. pylori infection is associated with reduced adult height in women, this maybe due to residual confounding.This revised version was published online in July 2005 with corrections to the author group.  相似文献   

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