Application of reverse-phase h.p.l.c. for the determination of partition coefficients     

Charles V. Eadsforth 《Pest management science》1986,17(3):311-325

Reverse-phase high performance liquid chromatography (h.p.l.c.), using a C₁₈ analytical column, has been applied to the determination of partition coefficients for a range of agrochemicals and industrial chemicals. Using a correlation plot of the logarithm of the capacity factor (k) with the logarithm of the n-octanol/water partition coefficient (P_ow), partition coefficients were predicted with a 95% tolerance interval of ± log 0.80 of the literature ‘shake flask’ value for compounds of random structure over the log P_ow range 0–6. Individual regression lines were fitted for compounds of comparable size and functional grouping, which reduced any bias and thereby enabled more accurate predictions to be made. The reverse-phase h.p.l.c. method has a number of advantages over the traditional ‘shake-flask’ method. Quantitative methods are not required or do not have to be developed and only the determination of the retention time is necessary. Quick and precise determinations of retention times are facilitated by h.p.l.c. and further improvement can be obtained by automation of solvent mixing, solute injection and data processing. H.p.l.c. was used to generate partition coefficient data for highly hydrophobic materials and, because of its resolving power, data for mixtures and solvent fractions. Dual detection, using u.v. and r.i. in series, was necessary for some compounds, particularly unknown mixtures and impure compounds. Calculations of log P_ow based on the fragment-addition method using the structural data file, MACCS, was of considerable value in confirming experimentally derived values. In certain cases, calculated log P_ow values were considered more trustworthy than experimental values.  相似文献   

CABI/EPPO distribution maps of plant pests and plant diseases and their important role in plant quarantine     

N. M. Pasiecznik  I. M. Smith  G. W. Watson  A. A. Brunt  B. Ritchie  L. M. F. Charles 《EPPO Bulletin》2005,35(1):1-7

Never before has the need for accurate distribution data for plant pests been so important. CAB International (CABI) and EPPO are international organizations with a long history and strong involvement in collating and disseminating information on the global distribution of plant pests. Distribution Maps of Plant Pests and Distribution Maps of Plant Diseases, first published in 1951 and 1942, respectively, are respected, referenced sources of such data, expertly compiled and validated and used by plant health organizations around the world. They have been joint CABI/EPPO publications since 1997, and provide an essential complement to expanding knowledge on plant pest distribution. The Distribution Maps continue to be the most authoritative sources of information on the presence and extent of specific plant pests, sourced from the 4.5 million records in CAB Abstracts as a basis and numerous other sources. They also feed directly into CABI's Crop Protection Compendium (CPC) and EPPO's Plant Quarantine Data Retrieval System (PQR) databases. Their history, compilation and value are discussed.  相似文献   

Pheochromocytoma in an aged female African elephant (Loxodonta africana).     

Christopher J Bonar  Albert H Lewandowski  Baha Arafah  Charles C Capen 《Journal of zoo and wildlife medicine》2005,36(4):719-723

A 43 yr-old female African elephant (Loxodonta africana) collapsed acutely and died. Necropsy revealed an enlarged right adrenal medulla. Histologic appearance was typical of pheochromocytoma. Special stains and electron microscopy demonstrated chromaffin granules, suggesting that the tumor was derived from catecholamine secreting cells of the adrenal medulla, and may have been functionally secretory. Serum levels of both norepinephrine and epinephrine were elevated at time of death, supporting the functional nature of the tumor. Histologic findings of arteriolar sclerosis and smooth muscle hyperplasia suggested that the animal may have suffered from chronic systemic hypertension. Pheochromocytoma should be considered as a differential diagnosis in cases of suspected hypertension and acute death in elephants.  相似文献   

中国北方番茄主要病毒种类普查及TMV、CMV株系鉴定   总被引：3，自引：0，他引：3  

冯兰香  田如燕  杨翠荣  杨又迪 《植物保护学报》1996,23(1):51-55

1990—1994年,对中国北方15省(市)番茄4种主要病毒种类进行了普查,在3761份样本中,烟草花叶病毒(TMV)和黄瓜花叶病毒(CMV)的检出率分别为34.5％—65.7％和11.6％—62.6％,马铃薯X病毒(PVX)和马铃薯Y病毒(PVY)的检出率一般为10％—20％。与此同时,也对番茄上的TMV和CMV进行了与抗病毒育种紧密相关的株系分化研究,在333个TMV分离物中鉴定出0、1、2和1.2株系,以0和1株系为主,在绝大多数省(市)中分别占分离物的50％和30％以上;在232个CMV分离物中鉴定出轻花叶、重花叶、坏死和黄化株系,以轻花叶和重花叶株系为主,在绝大多数省(市)中分别占分离物的30％和50％以上,这一研究结果为番茄病毒病的综合防治和抗病毒育种提供了科学依据。  相似文献   

Mechanisms conferring resistance of Western flower thrips to bendiocarb     

Guangyu Zhao  Wei Liu  Charles O. Knowles 《Pest management science》1995,44(3):293-297

Mechanisms associated with bendiocarb resistance were examined in two strains of western flower thrips, Frankliniella occidentalis (Pergande), that differed in their susceptibility to this carbamate by 13.6-fold. No appreciable differences between the two strains in [¹⁴C] bendiocarb penetration and excretion were detected; however, bendiocarb was metabolised substantially faster by the resistant KCM thrips than by the more susceptible UMC thrips. No appreciable difference between the two strains was found in the sensitivity of acetylcholinesterase activity to inhibition by bendiocarb. It was concluded that bendiocarb resistance in KCM western flower thrips was due to enhanced metabolism that probably was mainly oxidative in nature.  相似文献   

The dietary toxicity of flocoumafen to hens: Elimination and accumulation following repeated oral administration     

Charles V. Eadsforth  Alan Gray  Keith R. Huckle  Christopher Inglesfield 《Pest management science》1993,38(1):17-25

In a dietary toxicity study, laying hens received a diet containing the rodenticide flocoumafen at concentrations of 1.5, 5, 10 and 50 mg kg^?1 for five consecutive days. The LC₅₀ at termination following a 28-day observation period was 16.4 mg kg^?1. Livers of birds which received doses of flocoumafen between 5 and 50 mg kg^?1 had concentrations of flocoumafen (1.5 nmol g^?1) that were independent of dose. The data indicate the presence in hen liver of a saturable high-affinity flocoumafen binding site with similar characteristics and capacity to that of the quail and rat. Residues of flocoumafen in samples of breast and leg muscle were low in all exposure groups. Higher, dose-related residues were found in samples of abdominal fat and skin-associated fat and there was a clear demonstration of the transfer of dose-related residues into eggs. In a separate study in which hens were dosed with [¹⁴C]flocoumafen for five consecutive days at a daily rate of 1 and 4 mg kg^?1 body weight, the majority (68 %) of the daily radioactive dose was eliminated over the following 24 hours via excreta. Residues in liver at death or when killed accounted for < 1 % of the cumulative administered radioactivity. Residues in eggs were located primarily in the yolk with maximum concentrations 1.0 mg kg^?1 or 0.18% of the low dose; 2.1 mg kg^?1 or 0.06% of the high dose as [¹⁴C]flocoumafen equivalents were observed at 10 days after start of dosing. Some 40 % of the total activity in the yolk was unchanged flocoumafen.  相似文献   

SURGICAL TREATMENT OF DISEASES OF THE PLEURA, MEDIASTINUM AND THORACIC CAGE     

Charles D. Knecht V.M.D.  M.S. 《Veterinary surgery : VS》1973,2(2):19-23

The pleura, mediastinum and thoracic cage are rarely the center of attention for disease in the dog and the cat. Most often these structures are viewed as the wrappings for vital structures; their presence appears most often to interfere with visualization and palpation and impede surgical repair.  相似文献   

PRIME LAMB PRODUCTION     

W. J. Pryor  D. D. Charles 《Australian veterinary journal》1968,44(5):206-206

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THE ROLE OF THE VETERINARIAN IN THE MEAT INDUSTRY     

D. D. Charles  B.V.Sc. 《Australian veterinary journal》1968,44(5):223-226

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Poultry environment in the U. K. A review of progress     

D R Charles 《World's poultry science journal》1970,26(1):422-434

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