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On the basis of ESR spectra, humic substances are believed to be hydroquinone type polymer radicals with considerable cation exchange and redox capacity. All 3d-transition metal humates appear to be ionic high spin complexes. Manganese (II) ions doped in raw peats and peat humic acids are coordinated octahedrally with six oxygen-containing functional groups, e.g., carboxylate, phenolic, hydroxyl, carbonyl ligands, whereas copper (II) ions are in square planar arrangement with two carboxylate and two aliphatic nitrogen ligands. Doping with vanadyl(II) ions results in a square pyramidal arrangement with four oxygen-containing ligands. Diamagnetic manganese(VII), chromium(VI), molybdenum (VI) and vanadium(V) oxoanions in acidic solution are reduced by humic acids into paramagnetic manganese(II), chromium(III), molybdenum(V) and vanadium(IV) ions. Diamagnetic copper(I) ions, on the other hand, are oxidized by humic acids into paramagnetic copper(II) ions.In contrast to polyronic acid gels with outer-sphere structure, 3d-transition metal ions are generally bound to humic acids as inner-sphere chelate complexes. 相似文献
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A study has been made on the infrared spectra of lowland peats and purified humic, hymatomelanic and fulvic acids, as well as their acetylated derivatives and metal complexes. Extraction and purification may modify humic acids of untreated peats only to a small extent. Acetylation of fulvic and humic acids with acetic acid anhydride resulted mainly in the reaction of phenolic hydroxyl and quinone groups. Similarities of the spectra of the individual humic substances point to similar structures, differing only in the number of functional groups and the degree of aggregation. Metals are bound by humic substances mainly in metalcarboxylate bonds. The degree to which these bonds are ionic or covalent can be determined by the antisymmetric carboxylate stretching frequencies. 相似文献
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Hornok S Edelhofer R Joachim A Farkas R Berta K Répási A Lakatos B 《Acta veterinaria Hungarica》2008,56(1):81-88
Blood samples were collected from 330 cats in Hungary in order to evaluate their seroconversion to Toxoplasma gondii and Neospora caninum using the indirect fluorescent antibody test (IFAT). The overall prevalence of toxoplasmosis was 47.6%, the prevalence being 22.4% among urban, 50% among suburban and 61.3% among rural animals. Significantly more cats had high IFAT titres (1:640 to 1:5120) in the countryside. Female cats were more frequently infected with T. gondii than males (53.3% vs. 39.3%), and seropositivity increased with the age of animals. The prevalence (0.6%) and titre (1:40) of antibodies to N. caninum was low. Sixty-two cats were also screened for seroconversion to feline infectious peritonitis (FIP) virus. Higher titres to T. gondii were more frequently detected among FIP-positive cats, but this difference was non-significant due to the small number of cats with concurrent infection. 相似文献
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Demeter Z Lakatos B Palade EA Kozma T Forgách P Rusvai M 《Veterinary microbiology》2007,122(3-4):258-269
To achieve proper diagnosis of dogs based on acute clinical symptoms and poorly preserved field samples taken from animals that died due to canine distemper (CD), a new differential diagnostic test has been developed based on polymerase chain reaction (PCR). In this study, more than 150 samples collected from dogs showing respiratory, gastrointestinal and neurological signs suggesting canine distemper virus (CDV) infection were examined. The samples consisted of urine, blood and nasal swabs collected from clinically ill patients, sent to our laboratory by clinicians from various veterinary clinics throughout Hungary. Various organs collected during the necropsy of dogs with pathological changes that suggested CDV infection were also included. Three distinct PCRs were designed. For diagnostic purposes, a primer pair specific to a 409 bases-long segment within the conservative part of the large polymerase region (L) of the CDV genome was designed. Using this test, out of the 150 analyzed samples, 46 (30.66%) proved to be positive for CDV, indicating that CDV still represents a high risk to the canine population in Hungary. For the phylogenetical analysis, a primer pair that completely encompasses the hemagglutinin (H) gene of the CDV genome was designed. The amplicons of this region were sequenced in both directions using the appropriate primers. Our results indicate that several different CDV genotypes are currently present in Hungary. Nine of the analyzed Hungarian strains turned out to belong to the so-called Arctic group of CDVs, and were most closely related to non-European strains from North America, China and Greenland, as well as to the phocine distemper virus 2 (PDV-2) isolated from Baikal seals (Phoca sibirica). One of the Hungarian strains showed high similarity to other European isolates from Denmark, Germany, Italy and Turkey, as well as to other isolates from geographically more distant regions, such as the USA. Three Hungarian strains seem to join a new cluster that is formed by only a couple of strains, one isolated from a mink in Denmark, and another from a dog in North America. Using a third set of primers, a restriction fragment length polymorphism (RFLP) assay has also been designed for the fast and reliable differentiation of the wild-type CDVs from the vaccine strains. 相似文献
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Nasal and frontal sinus mucosa of the adult dog contain numerous olfactory sensory neurons and ensheathing glia 总被引：4，自引：0，他引：4
Skinner AP Pachnicke S Lakatos A Franklin RJ Jeffery ND 《Research in veterinary science》2005,78(1):9-15
Olfactory glial cells have been the focus of much recent research interest because of their possible future use as cellular transplants in repair of spinal cord injury. Although olfactory glial cells can be collected from the olfactory bulb for in vitro culture, alternative sites would be preferable for safer surgical access. This study was designed to investigate the distribution of olfactory sensory neurons and olfactory glial cells within the canine peripheral olfactory system. Using immunohistochemistry and electron microscopy on perfused tissue we demonstrate that olfactory sensory neurons are found in both the caudal nasal and the frontal sinus epithelia. Olfactory ensheathing glia were found in the mucosa at both these sites implying that surgical access for harvesting cells for transplantation would be straightforward. 相似文献
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Ilona Szabó Ferenc Lakatos György Sipos 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(1):159-168
Invasive Phytophthora species are responsible for severe tree diseases in many forest ecosystems in Europe. In Hungary, the symptoms were first noted when P. alni infection led to a serious decline and mortality of alder stands in the late 1990s. Between 2001 and 2009, over 300 soilborne Phytophthora isolates were collected from declining broadleaf forests in Hungary, and 10 Phytophthora species identified based on morphological traits and the molecular characteristics of the internally transcribed spacer (ITS) regions of the nuclear ribosomal DNA. The most diverse species spectrum, found in diseased alder stands, included P. gonapodyides, P. gregata, P. inundata, P. lacustris, P. megasperma, P. plurivora, one informally designated taxon: P. taxon hungarica, and one unnamed species P. sp.1. P. cactorum and P. plurivora isolates were prevalent in the soil of a declining eastern black walnut forest, and three species, P. gonapodyides, P. multivora and P. plurivora were recovered from a declining oak stand. More than one ITS-based genotype was identified for four species, including six genotypes for P. gonapodyides, and two each for P. cactorum, P. plurivora and P. inundata. The high genetic diversity of the P. gonapodyides isolates may indicate that the species is indigenous to the region. In contrast, the frequently recovered, widely distributed P. lacustris with a single ITS genotype may represent a recent colonizer. The P. multivora isolates are, to date, the first reported from a European native forest. 相似文献
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Imre J. Holb Barbara Balla Ferenc Abonyi Mónika Fazekas Péter Lakatos József M. Gáll 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(3):469-483
Temporal development of brown rot (Monilinia fructigena) on fruits was analysed in two organic apple orchards on three apple cultivars in Eastern Hungary from 2002 to 2006. The
three-parameter logistic function gave the best fit to brown rot over four non-linear growth functions in all cultivars, years
and orchards. Depending on location, year and cultivar, disease increased continuously from 6 to 8 weeks before harvest up
to harvest, reaching 19–37% of disease incidence. Disease variables of Y
f
, the final disease incidence; β, relative rate of disease progress; AUDPC
S
, standardized area under disease progress curve; T
1.5
, the time when disease incidence reaches 1.5% (day), and M, the inflection point were derived from the three-parameter logistic function. The disease variables of Y
f
, β, and AUDPC
S
were used in a computer simulation for predicting temporal brown rot development, and the disease variables of T
1.5
, M, and Y
f
were used to determine threshold values for epidemic intensity. Afterwards these were used to construct a fundamental model
for developing a brown rot forecasting and management strategy (BRFMS). The fundamental model contained four parts: i) data
insertion and analyses by computer simulation of pathogen submodels, ii) calculation of yield loss threshold levels based
on disease incidence, iii) determination of epidemic intensity levels and iv) a decision module with suggestions for disease
management practices for each epidemic intensity level. The fundamental model was supplemented with the prediction of occurrence
of the first fruit rot symptoms and with the insect injury prediction related to brown rot development in order to complete
a BRFMS for organic apple orchards. In a 3-year field evaluation from 2006 to 2008, season-long application of BRFMS treatments
reduced the number of sprays against brown rot by 22–33% compared with the treatments of general spray schedules against brown
rot. 相似文献