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1.
Poultry litter is a mixture of excreta, feed, feathers, and bedding material. Poultry litter is useful as a fertilizer due to the presence of nitrogen, phosphorus, and potassium. Litter is commonly used for growing corn, soybeans, potatoes, tomatoes, leafy vegetables, and cover crops. The aqueous leachate of poultry litter has been shown to exhibit toxicity to a variety of indicator organisms. The objective of this research was to identify classes of toxicants in the litter aqueous leachate. The aqueous extract of poultry litter was subjected to toxicity identification tests approved by the United States Environmental Protection Agency that use Ceriodaphnia dubia as the test organism. Tests performed included pH adjustment, filtration, aeration, C18 solid-phase extraction, EDTA addition, sodium thiosulfate addition, and extraction through zeolite. Zeolite extraction, filtration at low pH, and aeration at low pH reduced overall toxicity by 68, 20, and 22%, respectively. The major sources of toxicity appear to be ammonia and anionic organic compounds. Toxicity was apparently not due to the presence of heavy metals or oxidants.  相似文献   

2.
Gallium nitrate is active against lymphoma and bladder cancer; however, little is understood about tumor resistance to this drug. Transferrin, the iron transport protein, increases gallium uptake by cells, whereas pyridoxal isonicotinoyl hydrazone (PIH), an iron chelator, transports iron into cells. Therefore, we examined whether these metal transporters would increase the cytotoxicity of gallium in gallium nitrate-resistant CCRF-CEM cells. Transferrin, in increasing concentrations, enhanced the cytotoxicity of gallium nitrate. One mg/ml transferrin decreased the 50% inhibitory concentration of gallium nitrate from 1650 to 75 micrometer in gallium-resistant cells and from 190 to 150 micrometer in gallium-sensitive cells. Transferrin also enhanced the cytotoxicity of gallium even at drug concentrations that were not growth inhibitory. The gallium chelate Ga-PIH inhibited the growth of both gallium nitrate-resistant and -sensitive cells. Fifty micrometer Ga-PIH inhibited cellular proliferation by 50%, whereas similar concentrations of PIH or gallium nitrate were not growth inhibitory. However, because higher concentrations of PIH also inhibited cell growth, the cytotoxicity of Ga-PIH was greater than PIH only at concentrations of <100 micrometer. Cross-titration experiments demonstrated that the cytotoxicity of PIH was partially reversed by gallium nitrate, whereas the cytotoxicity of gallium nitrate was enhanced by PIH. Our studies suggest that Ga-PIH warrants further evaluation as a potential antineoplastic agent. Because transferrin increases the cytotoxicity of gallium nitrate in transferrin receptor-bearing, gallium nitrate-resistant cells, future clinical trials of this drug should incorporate the development of strategies to increase plasma transferrin levels.  相似文献   

3.
This paper describes research on the electrical stunning of poultry and the problems of achieving an effective humane stun with water bath stunners. The welfare and meat quality advantages of using gas mixtures to stun and kill birds are then described. The evidence strongly suggests that chickens and turkeys can be killed very humanely using either 90% argon in air or a mixture of 30% carbon dioxide and 60% argon in air.  相似文献   

4.
Apparent digestibility of minerals by lactating cows from a multiple-component, conventional Israeli TMR (control) and from a TMR containing 10% poultry litter (DM basis) was examined. Ten cows in early lactation were divided into two groups of similar performance (39 kg of milk/d) and fed for ad libitum intake the two TMR for 28 d. Poultry litter contributed, as a percentage of total requirements, 44.4% of Ca, 41.0% of P, 32.0% of S, 22.8% of Mg, and 25.9% of K. Apparent digestibility of the macroelements was higher for cows fed the TMR supplemented with poultry litter than for those fed the control TMR. Apparent digestibility of the control TMR was 22.3% for Ca, 29.4% for Mg, 39.1% for P, and 62.2% for S; the apparent digestibility of the treatment TMR was 30.1% for Ca, 45.6% for Mg, 45.3% for P, and 65.6% for S. Poultry litter contributed the entire requirements of Zn, Mn, and Co; 56% of Cu; and 32% of Se. The apparent digestibility of the control TMR was 15.6% for Cu, 39.6% for Zn, 8.51% for Mn, 42.8% for Co, and 41.6% for Se, and the apparent digestibility of the treatment TMR was 27.9% for Cu, 54.0% for Zn, 17.8% for Mn, 37.0% for Co, and 63.9% for Se. Poultry litter is a good source of macro- and microelements for lactating cows and, at 10% of the TMR, could ensure against mineral deficiencies.  相似文献   

5.
Processed poultry litter intended for dairy cattle feed was collected on 13 dairy ranches in the San Joaquin Valley of California and analyzed for the presence of significant bacterial pathogens associated with clinical disease in cattle or foodborne disease in humans. Litter samples were collected from the surface and interior of the litter piles upon arrival on the dairies and 2 to 4 wk later. Litter samples were cultured for Salmonella, Escherichia coli, Campylobacter, and other bacteria. The temperature of the litter piles was obtained on the surface and interior at each sampling. Dry matter was determined for each sample. No Salmonella, E. coli O157, or Campylobacter was identified (n = 104). Other E. coli strains were found in 8 out of 52 samples on arrival and 4 out of 52 samples at 2 to 4 wk after arrival. Although the surface and interior temperatures of the litter pile were different (23 C vs 50 C, respectively), the mean temperatures did not significantly change with time on the ranches. Average dry matter content did not differ between samples. In conclusion, the pathogens under investigation were not detected in processed poultry litter on these California dairy ranches upon arrival at the dairy or 2 to 4 wk later.  相似文献   

6.
The Sj?bring system of personality dimensions measuring intellectual capacity, activity, impulsivity and sociability was used to study possible "salutogenic" (i.e. causes of health) effects. The study comprised 590 subjects investigated in 1947, 1957, 1972 and 1988-1989 in the Lundby project, an epidemiological study in Sweden. Psychiatric diagnoses were made in 1947, 1957 and 1972. Mental health was estimated in 1988-1989 using the concept "love well, work well, play well and expect well". The Sj?bring dimensions were clinically assessed in 1972. Both in the concurrent study in 1972 and in the prospective study in 1988-1989 "super capacity" (high intellectual function), "super validity" (high activity level) and "super solidity" (low impulsivity) were statistically associated with lower frequencies of certain psychiatric diagnoses and a higher frequency of positive mental health. These variables are proposed to increase coping capacity, and therefore increase stress resilience.  相似文献   

7.
Platelets have been suggested to play a role in the inflammatory response, including defence against bacteria. The aims of this study were to determine in vivo platelet activity during the clinical course of pulmonary tuberculosis and to investigate whether or not there is a correlation between the magnitude of platelet activation and the extent of the pulmonary disease. T-lymphocyte activity was also analysed in the patients. Platelet factor-4 (PF4) and soluble interleukin-2 receptor-alpha (sIL-2Ralpha) concentrations were used as markers of platelet and T-lymphocyte activation, respectively. Twenty-five patients with pulmonary tuberculosis were studied. Fifteen healthy subjects served as a control group. The levels of both sIL-2Ralpha (3,000+/-1,948 pg x mL(-1)) and PF4 (103.1+/-6.7 IU x mL(-1)) were significantly higher in the patients with tuberculosis than in the control group (984+/-360 pg x mL(-1) and 78.2+/-23.9 IU x mL(-1), respectively) (Mann-Whitney U-test, p<0.001 for both comparisons). The plasma PF4 levels were found to be well correlated with the extent of pulmonary lesions on chest radiography (the Spearman's bivariate correlation analysis, r=0.65, p<0.001). However, sIL-2Ralpha concentrations did not correlate with the extent of disease. In conclusion, it has been suggested that platelet and T-lymphocyte activation occurs during pulmonary tuberculosis. The good correlation between platelet activation and the extent of pulmonary tuberculosis might be ascribed to a pathophysiological role of platelets in pulmonary tuberculosis.  相似文献   

8.
The biodegradability of two surfactants, Triton X-100 and Rhamnolipid, was tested under aerobic, nitrate reducing, sulfate reducing, and anaerobic conditions in a respirometer. The results indicated that from a biodegradation standpoint, Rhamnolipid is superior to Triton X-100 since it is biodegradable under all conditions, whereas the Triton X-100 is partially biodegradable under aerobic conditions and nonbiodegradable under anaerobic, nitrate reducing, and sulfate reducing conditions.  相似文献   

9.
This work studies the ozonation of the pharmaceutical propranolol (PRO) in aqueous solution. Experimental results demonstrated that ozonation was an efficient method to remove PRO, achieving its complete abatement after 8?min of treatment (ozone dose of 0.47??mmol?L-1), starting from a PRO initial concentration of 0.38??mmol?L-1. The total organic carbon (TOC) analysis indicated that 1?h of ozonation (ozone dose of 3.54??mmol?L-1) was able to achieve only about 5% of the total organic carbon removal. The ozonation of PRO aqueous solutions has not promoted a prompt increase of the ratio of biological oxygen demand to chemical oxygen demand, thus indicating the need for higher ozone doses to initiate the biodegradability enhancement. The acute toxicity increased in the first minutes of reaction with a posterior reduction to values slightly higher than the toxicity of the PRO raw solution. Some early intermediate structures were proposed, and finally, kinetic constants for the direct attack of ozone on PRO structure were calculated. These values are in the order of magnitude of 105??L?mol-1?s-1.  相似文献   

10.
Antimicrobial activities were examined for major antibacterial agents against clinically isolated microbial strains which were isolated and identified from materials collected from inpatients with various infections in 1988, 1989 and 1990, and the following conclusions were obtained. 1. Among strains isolated each year, methicillin-resistant Staphylococcus aureus (MRSA) were found frequently. 2. CEPs-resistant Escherichia coli strains were observed among strains isolated each year. 3. Increasing tendencies in resistances of Citrobacter freundii, Enterobacter spp., Serratia marcescens to cephems and new quinolones were observed. 4. Increasing tendencies in resistances of Proteus vulgaris to ceftazidime (CAZ) and new quinolones appeared to exist. 5. Among strains isolated each year, resistances of Pseudomonas aeruginosa to CAZ and quinolones were observed in high rates, but also their resistances to imipenem appeared to increase. 6. Many of recently increasing multiple resistant bacteria seem to have different sites of drug action and/or to have non-hydrolytic modes of resistance.  相似文献   

11.
以十二胺耗氧生物降解的优化环境条件为基础,利用CO2生成量法测试水体中M-302和M-331两种新型捕收剂的生物降解性能,并分析其环境安全性。结果表明:十二胺28d的生物降解较佳环境条件为气流量8L/h,恒温水浴温度(25±1)℃,活性污泥质量浓度50 mg/L,受试物质量浓度10 mg/L;相同条件下,M-302和M-331的生物降解率分别为52.76%和32.44%,生物降解性指数(IB)分别为143.47和99.84,表明在可控条件下,M-302在短期内可人工降解,值得推广使用,而M-331的降解情况不理想,不宜大量使用。  相似文献   

12.
A steady-state laboratory-scale sequencing batch reactor process for biological phosphorus removal (BPR) was developed, and the influence of wastewater biodegradability on BPR was studied in batch tests. Biodegradability was expressed in this work as the readily biodegradable fraction of wastewater COD (rbCOD) present in the mixed liquor after the anaerobic stage of the anaerobic/oxic cycle of the BPR process. The rbCOD fraction was changed by varying the organic composition of synthetic wastewater (different carbohydrates were used: saccharose, cellobiose, starch, and cellulose) or varying the anaerobic retention time (1.25, 4, 9, and 24 h) when only one kind of low biodegradable synthetic wastewater (starch composed) was used. A clear positive trend was observed between rbCOD and anaerobic P release, but such a clear relationship was not observed with BOD5 measurements. Soluble carbohydrates allowed a BPR mechanism, but particulate carbohydrates seemed to cause nonbiological P removal. An increase in anaerobic retention time improved rbCOD concentrations up to 50%, approximately, and P removal, but excessive retention times, >9 h, should be used to reach good BPR results.  相似文献   

13.
Excessive specialization and high production requirements place high demands on the metabolism of poultry. A number of metabolic problems, such as disturbances of energy metabolism (affecting mainly hens) and mineral balance (affecting mainly laying hens), affect performance. Nearly all these problems are multifactorial in nature, but diet, and in particular the interaction between diet and phenotype, plays an important role. The problem of ascites in broiler hens is discussed in relation to external and genetic causative factors. Genetic factors can be further subdivided into structural and functional causative factors. This distinction has important consequences. For example, sudden death syndrome can be distinguished as a separate entity. Fatty liver syndrome in laying hens, and gout and urolithiasis in chicks and hens are briefly discussed. Finally, some of the most important or most common skeletal problems affecting poultry, namely, tibial dyschondroplasia, battery fatigue, rickets, and chondrodystrophy, are briefly discussed in the context of the dietary factors that underlie these disorders or which can be used as treatment.  相似文献   

14.
Conditions were devised to avoid protease activity during the preparation and the subsequent handling of nuclear particles containing hnRNA. During all the steps of preparation of rat liver particles, the presence of phenylmethyl sulfonyl fluoride (PMSF) was required for the reproducibility of the results. It probably inhibited the cellular serine proteases before the separation of the particles from the other cellular structures. Protease activity was detected in the rat liver particles. The enzyme(s) preferentially hydrolyzed a few particle polypeptides. It was not inhibited by PMSF, nor by two trypsin and chymotrypsin-like protease inhibitors, nor by iodoacetamide, but was inhibited by sodium bisulfite and para-hydroxymercury benzoate (PHMB). PHMB was preferred above bisulfite because it could be used at lower concentration. It proved useful when particles were to be incubated at 37 degrees C. A protease hydrolysing the same polypeptides as the liver enzyme was also detected in rat brain particles. However, its activity was much lower in this tissue and the presence of protease inhibitors was not absolutely required under the standard conditions of preparation and handling of brain particles.  相似文献   

15.
BACKGROUND: The normal conjunctival flora is one of the main sources of intraocular contamination during cataract surgery. The theory that the positive anterior chamber (AC) pressure during phacoemulsification (phaco), and the smaller wound utilised, might reduce the rate of contamination was studied. METHODS: The peroperative AC aspirates of 210 consecutive patients undergoing cataract surgery were assessed. In group 1, 100 patients underwent a standard extracapsular cataract extraction (ECCE). In group 2, 110 patients underwent phacoemulsification of the crystal-line lens through a scleral tunnel. AC aspirates from the Simcoe irrigation/aspiration cannula (group 1) and phaco probe (group 2) were collected and microbiological studies performed after direct and enrichment cultures. RESULTS: There were 29 (29%) positives in the ECCE group compared with 22 (20%) positive cultures from AC aspirates in the phaco group. Coagulase negative staphylococcus (CNS) was the commonest contaminant in both groups. CONCLUSION: Although there was a higher rate of AC contamination during ECCE, the difference was not statistically significant (p > 0.10, chi 2 = 2.31).  相似文献   

16.
Mineral and microbial content of water affects the performance of poultry. Because poultry production can adversely affect water quality, the Environmental Protection Agency monitors and regulates its impact. Management of nonpoint source water contamination is especially important. If properly managed, litter, a valuable secondary commodity associated with poultry production, can be used as fertilizer, food, or energy.  相似文献   

17.
The single Fenton or the Fenton process implemented in combined scheme as a posttreatment after the ferric chloride coagulation was applied for leachate collected from a real waste disposal site. Depending on the ratios of H2O2/chemical oxygen demand, H2O2/Fe2+, and pH, the Fenton oxidation or both the Fenton oxidation and the Fenton coagulation were involved in chemical oxygen demand reduction. The implementation of ferric chloride coagulation as a pretreatment stage or acidification of raw leachate did not result in the improvement of chemical oxygen demand reduction efficacy of the following Fenton process comparing with that obtained by the direct Fenton treatment of raw leachate. The direct Fenton treatment with a higher (3/1) H2O2/chemical oxygen demand ratio applied to raw leachate without pH preadjustment (H2O2/Fe2+ = 10/1), produced more oxidized organic compounds (measured as dissolved organic carbon/chemical oxygen demand ratio), more biodegradable by-products (measured as a 7-day biological oxygen demand/chemical oxygen demand ratio), and required a considerably lower dosage of NaOH for neutralization, making it preferable for the leachate treatment. Although up to a twofold reduction in the toxicity was observed after the overall Fenton process application, the treated leachate remained extremely toxic to Daphnia magna.  相似文献   

18.
Galactosyltransferase specific activities in embryonic chick retina, optic tectum, and telencephalon were found to decline during embryonic development. Incorporation of galactose from nucleotide sugar into exogenously added glycoprotein acceptor was measured in the presence of excess of glycoprotein acceptor. This ensured that the specific activity measurements were reflections of tru enzyme specific activity rather than availability of acceptor. Moreover, we have shown that the decline in specific activity is not due to degradation of the nucleotide sugar, UDP-galactose, under our in vitro assay conditions. Enzymatic specific activity declined sharply with embryonic age for all tissues tested. This decline was not affected by the presence of 5-bromodeoxyuridine during in vitro culture of embryonic chick neural retina above that caused by the culturing alone. Galactosyltransferase activity was not found to be associated with the plasma membrane fraction from homogenized tissue but rather with the microsomal fraction. Thus, the changes in galactosyltransferase specific activity detected here do not reflect changes at the cell surface.  相似文献   

19.
我国城市生活垃圾堆肥处理展望   总被引:1,自引:0,他引:1  
好氧堆肥是城市生活垃圾无害化处理的主要方法之一.本文结合我国的实际情况对垃圾堆肥工艺技术状况,存在的主要制约因素,以及如何改进垃圾堆肥的被动局面,合理确定 堆肥处理规模和生产工艺方案,提高堆肥产品质量和发展前景等方面提出了许多见解,为我国垃圾堆肥状况的改善提供参考.  相似文献   

20.
Bacterial enteritides of poultry   总被引:1,自引:0,他引:1  
We report an experimental system for abundant expression of specific peptide-class II complexes in vivo and in vitro. We have constructed a cassette which allows for the replacement of the CLIP region of invariant chain (Ii) with an antigenic peptide. In fibroblasts expressing an altered Ii protein, in which CLIP has been replaced with peptide 52-68 from the class II I-E alpha chain (pEalpha), pEalpha-I-Ab complexes are formed with high efficiency. This peptide loading occurs in the endoplasmic reticulum (ER) when the Ii:pEalpha fusion protein associates with the I-Ab alpha and beta chains. The trimeric complexes of Ii:pEalpha and I-Ab molecules are stable in SDS and can be detected by the pEalpha-I-Ab-specific mAb, YAe, indicating that pEalpha is bound in the class II groove in the context of full-length Ii. These data strongly suggest that the CLIP region of intact Ii prevents peptide loading in the ER by binding in the peptide binding groove of newly synthesized class II alphabeta dimers.  相似文献   

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