An octahedral coordination complex of iron(VI)     

Berry JF  Bill E  Bothe E  George SD  Mienert B  Neese F  Wieghardt K 《Science (New York, N.Y.)》2006,312(5782):1937-1941

The hexavalent state, considered to be the highest oxidation level accessible for iron, has previously been found only in the tetrahedral ferrate dianion, FeO4(2-). We report the photochemical synthesis of another Fe(VI) compound, an octahedrally coordinated dication bearing a terminal nitrido ligand. M?ssbauer and x-ray absorption spectra, supported by density functional theory, are consistent with the octahedral structure having an FeN triple bond of 1.57 angstroms and a singlet d2(xy) ground electronic configuration. The compound is stable at 77 kelvin and yields a high-spin Fe(III) species upon warming.  相似文献   

Discrimination of alleles and copy numbers at the <Emphasis Type="Italic">Q</Emphasis> locus in hexaploid wheat using quantitative pyrosequencing     

Sebastian Förster  Erika Schumann  W. Eberhard Weber  Klaus Pillen 《Euphytica》2012,186(1):207-218

Speltoid spikes are characterized by pyramidal spike morphology featuring an elongated rachis and tenacious glumes. Speltoids are considered undesirable spike aberrants in wheat breeding leading to increased heterogeneity within a cultivar candidate. As a consequence, the presence of speltoids may result in rejection of a cultivar candidate during official field trials or denial of cultivar certification during seed multiplication. A reliable method is, thus, required to assess the occurrence of speltoids, early on in a wheat breeding program. The domestication gene Q located on the long arm of wheat chromosome 5A is known to suppress the speltoid phenotype in wheat. Here, a quantitative pyrosequencing assay was developed to distinguish between normal wheat plants, which possess two copies of the Q allele, and aberrants, which are either aneuploids lacking the correct number of chromosome 5A copies or plants which carry the primitive q allele. An accurate and reproducible determination of the Q gene copy number was achieved for different wheat genotypes based on homoeologous sequence quantification with two primer combinations at the Q locus. Single plants with one to four copies of the Q allele could be detected by quantitative pyrosequencing which corresponded to the occurrence of speltoid (1 Q allele), normal (2 Q alleles), and compact (more than 2 Q alleles) spikes. Q and q specific alleles could be differentiated at SNP position 2299 of the Q gene. This SNP is assumed to be related to the emergence of free-threshing wheat forms. To our knowledge this is the first report for detection of aneuploids and differentiation of Q alleles in bread wheat using pyrosequencing technology. In future, quantitative pyrosequencing assay can be applied in wheat breeding programs to carry out marker-assisted selection against the presence of speltoid spike aberrants.  相似文献   

EFFECTS OF OBSERVER ON THE DIAGNOSTIC ACCURACY OF LOW‐FIELD MRI FOR DETECTING CANINE MENISCAL TEARS     

Peter Böttcher  Eberhard Ludewig 《Veterinary radiology & ultrasound》2012,53(6):628-635

Low‐field MRI (lfMRI) has become increasingly accepted as a method for diagnosing canine meniscal tears in clinical practice. However, observer effects on diagnostic accuracy have not been previously reported. In this study, 50 consecutive stifle joints with clinical and radiologic evidence of cranial cruciate ligament insufficiency were investigated by lfMRI and arthroscopy. Fifteen observers who had varying levels of experience and who were unaware of arthroscopic findings independently reviewed lfMRI studies and recorded whether lateral and medial meniscal tears were present. Diagnostic accuracy (sensitivity, specificity, positive (PPV) and negative predictive value (NPV)) was determined for each observer and median values were calculated for all observers, using arthroscopy as the reference standard. Interrater agreement was determined based on intraclass correlation coefficient (ICC) analysis. Observer level of experience was compared with diagnostic sensitivity and specificity using correlation analysis. Based on pooled data for all observers, median sensitivity, specificity, PPV, and NPV for lfMRI diagnosis of lateral meniscal tears were 0.00, 0.94, 0.05, and 0.94, respectively. Median sensitivity, specificity, PPV, and NPV for medial meniscal tears were 0.74, 0.89, 0.83, and 0.79, respectively. Interrater agreement for all menisci was fair (0.51). Menisci were less consistently scored as having no tears (ICC = 0.13) than those scored as having tears (ICC = 0.50). No significant correlations between observer experience and diagnostic sensitivity/specificity were identified. Findings indicated that the accuracy of lfMRI for diagnosing canine meniscal tears was poor to fair and observer‐dependent. Future studies are needed to develop standardized and widely accepted lfMRI criteria for diagnosing meniscal tears.  相似文献   

Canine onchocercosis in Greece: report of further 20 cases and molecular characterization of the parasite and its Wolbachia endosymbiont     

Komnenou A  Egyed Z  Sréter T  Eberhard ML 《Veterinary parasitology》2003,118(1-2):151-155

Recently, sporadic cases of subconjunctival Onchocerca infection have been reported in dogs in Greece and Hungary. Herein we report further cases from Greece and the results of the molecular analysis of Onchocerca sp. removed from Greek dogs and its Wolbachia endosymbionts. Twenty dogs of various breeds, 1-11 years of age with subconjunctival onchocercosis (4 cases each in right or left eye, 12 cases in both eyes) were presented having similar manifestations. Periorbital swelling, exophthalmos, lacrimation, discharge, photophobia, conjunctival congestion, corneal edema, protrusion of the nictitating membrane, and subconjunctival granuloma or cyst formation were the most important clinical signs. After surgical excision of the periocular masses containing the worms, all animals recovered fully from onchocercosis. Based on the similarities of the clinical picture of the Greek and Hungarian cases, the similar morphology of the Greek and Hungarian isolates, and the identical sequences of the cytochrome oxidase gene of the filarial parasites and that of the 16S ribosomal RNA gene from their Wolbachia endosymbionts, the Onchocerca sp. isolated from dogs in Greece and Hungary appears to belong to the same species.  相似文献   

Adult Dirofilaria repens in a subcutaneous granuloma on the chest of a dog     

W. P. Bredal    B. Gjerde    M. L. Eberhard  †  M. Aleksandersen  D. K. Wilhelmsen  ‡ L. S. Mansfield  § 《The Journal of small animal practice》1998,39(12):595-604

A 10-year-old, 9 kg, intact male crossbred dog was treated for nasal mites with milbemycin oxime using a dose of 1 mg/kg bodyweight orally, three times at 10-day intervals. One month after the initiation of this treatment a subcutaneous nodule developed on the sternum of the dog. The nodule was removed and found to contain a single, 82 mm long, thread-like nematode. Several exotic parasites were suspected as possibilities because the dog had been imported to Norway from South Africa. Microfilariae were not detected in the blood and heartworm antigen tests were negative. The worm was identified morphologically as an adult, female Dirofilaria repens. This is the first report of D repens from Norway. The case is of interest because of the differential diagnostic problem it posed and because infestation was recognised following treatment of another parasitic condition with a broad-spectrum, antiparasitic drug. In addition, the case provides a reminder of the necessity to be aware of geographical differences in disease occurrence which can produce unexpected disease in non-endemic areas as a consequence of increased international travel with pets.  相似文献   

SIMSEPT – ein neues Prognosemodell zum Auftreten von Septoria tritici und Septoria nodorum     

Dietmar Roßberg  Eberhard Kluge  Erich Jörg 《Gesunde Pflanzen》2003,55(1):8-12

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OPERATIVE MANAGEMENT: PROTECTION OF RENAL FUNCTION     

Eberhard Rosin D.V.M.  † 《Veterinary surgery : VS》1974,3(1):48-50

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Ocular Onchocerca infections in two dogs in western United States     

Mark L. Eberhard  Ynes Ortega  Sharon Dial  Chris A. Schiller  Alson W. Sears  Ellis Greiner 《Veterinary parasitology》2000,90(4)

Two dogs, one from California and one from Arizona, were found to have aberrant infections caused by filarial nematodes of the genus Onchocerca. In both cases, the parasites are localized in or near the eye. In one case the worm was located in the cornea and was surgically removed. In the second case, a very marked granulomatous reaction was induced in the retrobulbar space, mimicking an abscess. This eye was enucleated. The worms in both instances were female, and were gravid, i.e. contained microfilariae in utero, indicating that a male worm(s) had been present and mating had occurred. The exact identity of the species of Onchocerca responsible cannot be determined, although the features observed are most like Onchocerca lienalis of cattle. These cases represent the fourth and fifth such cases reported from the US, and are especially interesting because of the unusual location of the worms, the small number of recognized cases, and the similarity to a recent zoonotic human infection.  相似文献   

Luftkapazität,nutzbare Feldkapazität und Feldkapazität von Substrat-Horizontgruppen - eine statistische Auswertung von Labordatenbanken     

Winfried Riek  Gerd Wessolek  Manfred Renger  Eberhard Vetterlein 《植物养料与土壤学杂志》1995,158(5):485-491

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Eine Methode zur Bestimmung austauschbarer Kationen in Waldböden     

Peter Trüby  Eberhard Aldinger 《植物养料与土壤学杂志》1989,152(3):301-306

A Method for the Determination of Exchangeable Cations in Forest Soils A simple extraction method with NH₄Cl was developed for determining exchangeable cations in forest soils. The influence of selected parameters (reaction time, concentration of NH₄Cl, filter medium etc.) affecting the amount of extractable cations was tested and a standardisation was done. The cation exchange was completed in less than 4 h. For a quantitative extraction of K, Mg, Ca, and Mn a concentration of 0.05 M NH₄Cl was sufficient. The extractable amount of these cations was always clearly defined. However, extracted Al and Fe increased with the NH₄Cl-concentration. Depending on the soil samples, the exchange is not quantitative even when using a saturated solution. The extractable H⁺ is nearly independent of the NH₄Cl-concentration. Probably considerable amounts are dissociated from organic acids. The optimized method is feasible and can be used for K, Mg, Ca, and Mn as an alternative to percolation methods.  相似文献