Soil metabolism of the herbicide napropamide in cereals, maize, sugar beet and vegetable field replacement crops

The metabolism of the herbicide napropamide has been studied in the field in the soil of replacement crops (cereals, corn, sugar beet, potato and several vegetables). Napropamide was soil applied in the autumn and the soil left fallow during the winter. Crops were sown in April of the following year and simulated the replacement crops that are grown in the event of failure of the first autumn-sown crop. Trials were made twice, i.e. during the 1987-1988 and 1988-1989 crop seasons. The soil metabolism of napropamide was also studied in a rose nursery. Napropamide was transformed by microbiological processes in the soil into the corresponding monoethylamide and acid. These compounds did not generally accumulate in the soil, and their individual concentrations did not exceed that of residual napropamide during the observed growing seasons. The kinetics, metabolic pathways and agricultural implications of the herbicide are briefly discussed.     

Comparative metabolism of R(-)-fenoprofen in rats and sheep

The chiral inversion of 2-arylpropionic acids occurs in many species. It is a unique reaction specific to this group of drugs. In this study R-(-)-fenoprofen (R-(-)-FPF) was used as a model compound to investigate metabolic chiral inversion in sheep in vivo and in vitro and to compare the data with the results obtained in rats. Metabolic inversion in sheep was 80%. The apparent mean values of Km and V _max of thioester formation were: 392 μm and 2.08 nmol/min/mg in sheep and 500 μm and 22 nmol/min/mg in rats. For hydroxylation, the apparent mean values were V_max: 0.02 nmol/min/mg in rats and 0.01 nmol/min/mg in sheep. There was no correlation between in vitro thioesterification and in vivo chiral inversion in sheep as compared to rats. In sheep most of the thioester formed underwent inversion (80%) while in rats, where in vitro thioesterification was greater, in vivo inversion was less (42%). In consequence, in rats other metabolic pathways for R(-)-FPF-CoA, such as incorporation into triacylglycerols and conjugation with amino acids, may be quantitatively more important     

COMPARISON OF SONOGRAPHIC FEATURES OF BENIGN AND NEOPLASTIC DEEP LYMPH NODES IN DOGS

The differentiation of benign vs. neoplastic lymph nodes impacts patient management. Specific sonographic features are typically considered when assessing lymph nodes in dogs. However, the usefulness of these criteria in distinguishing benign vs. malignant lymph nodes remains largely unknown, especially for deep lymph nodes. Our aim was to compare sonographic features in benign and neoplastic deep lymph nodes with the hope of identifying predictive criteria. Thirty‐one deep lymph nodes (16 mesenteric, 10 medial iliac, three hepatic, one sternal, and one cranial mediastinal) in 31 dogs were examined prospectively with B‐mode and Color flow Doppler. Lymph nodes were aspirated using ultrasound‐guidance and final diagnosis were established based on cytologic and/or histopathologic interpretation. Prevalence of each sonographic feature and combinations of two features was calculated for each group and compared using a χ²‐test or Student's t‐test for unequal variances. Ten lymph nodes were benign (hyperplastic and/or inflammatory) and 21 were neoplastic. All were hypoechoic, except for one neoplastic lymph node. Maximal short‐axis diameter (P=0.0006) and long‐axis diameter (P=0.01), and SA/LA ratio (P=0.008) were increased significantly for neoplastic (2.8, 5.5 cm, and 0.50, respectively) vs. benign (1.2, 3.8 cm, and 0.34, respectively) lymph nodes. The prevalence of other features was similar between groups. Doppler evaluation was possible in 77% of lymph nodes, but there was no significant difference between groups. When any two ultrasound features were combined, the only difference between benign and neoplastic lymph nodes was for the combination of contour regularity and appearance of the perinodal fat (P=0.03).     

Chirality of the sulphoxide metabolites of fenbendazole and albendazole in sheep

Two prochiral sulphide drugs, fenbendazole (FBZ) and albendazole (ABZ) were administered orally to sheep. Blood samples were analysed for parent drug and S-oxidation metabolites and the chirality of the sulphoxide metabolites was determined. The plasma concentrations of the enantiomers of the sulphoxides were never a racemate. On the contrary, the ratios were greater than 1 as soon as the sulphoxide compounds could be detected in plasma. They subsequently increased linearly throughout the time course of the kinetics, reaching the level 86:14 after FBZ and 95:5 after ABZ treatment. The major enantiomer represented 74% and 86% of the total AUC of SO.FBZ and SO.ABZ, respectively.     

木材声学-声波分等检测技术及工业应用

介绍了在应力波-超声波技术基础上发展起来的木材声学-超声波分等检测技术。通过测量超声波的传播速度以及一定时域内的传播能量，建立关系模型，对木材的抗弯弹性模量（MOE）和抗弯强度（σb）进行评估。该技术可在木结构建筑设计、木结构建筑现场调查、森林质量控制和管理等领域广泛应用。     

A correlation of toxicity of albendazole and oxfendazole with their free metabolites and bound residues

The possible correlations between embryotoxicity, plasma kinetics of toxic metabolites and covalent binding of metabolites to foetal tissues were studied using two drugs, albendazole and oxfendazole. In the rat, the metabolic inhibitor, SKF-525A, induced changes in embryotoxicity which were well correlated with plasma levels of identified embryotoxic metabolites, but not with the levels of foetal tissue bound drug metabolites.     

Linking changes in the soil microbial community to C and N dynamics during crop residue decomposition

Crop residues are among the main inputs that allow the organic carbon (C) and nutrients to be maintained in agricultural soil. It is an important management strategy that can improve soil fertility and enhance agricultural productivity. This work aims to evaluate the extent of the changes that may occur in the soil heterotrophic microbial communities involved in organic matter decomposition and C and nitrogen (N) mineralization after the addition of crop residues. Soil microcosm experiments were performed at 28°C for 90 days with the addition of three crop residues with contrasting biochemical qualities: pea (Pisum sativum L.), rapeseed (Brassica napus L.), and wheat (Triticum aestivum L.). Enzyme activities, C and N mineralization, and bacterial and fungal biomasses were monitored, along with the bacterial and fungal community composition, by the high-throughput sequencing of 16S rRNA and ITS genes. The addition of crop residues caused decreases in β-glucosidase and arylamidase activities and simultaneous enhancement of the C mineralization and net N immobilization, which were linked to changes in the soil microbial communities. The addition of crop residues decreased the bacterial and fungal biomasses 90 days after treatment and there were shifts in bacterial and fungal diversity at the phyla, order, and genera levels. Some specific orders and genera were dependent on crop residue type. For example, Chloroflexales, Inquilinus, Rubricoccus, Clitocybe, and Verticillium were identified in soils with pea residues; whereas Thermoanaerobacterales, Thermacetogenum, and Hypoxylon were enriched in soils with rapeseed residues, and Halanaerobiales, Rubrobacter, and Volutella were only present in soils with wheat residues. The findings of this study suggest that soil C and N dynamics in the presence of the crop residues were driven by the selection of specific bacterial and fungal decomposers linked to the biochemical qualities of the crop residues. If crop residue decomposition processes showed specific bacterial and fungal operational taxonomic unit (OTU) signatures, this study also suggests a strong functional redundancy that exists among soil microbial communities.     

The estimation of wind exposure for windthrow hazard rating: comparison between Strongblow, MC2, Topex and a wind tunnel study

This paper compares five different methods of wind exposureassessment in an attempt to identify a method that could servein windthrow hazard assessment. The candidate methods that wereselected are: a wind tunnel simulation, two numerical modelsbased on air flow behaviour (MC2 and Strongblow) and two empiricalmethods (Topex and Topex-to-distance). Best correlations withthe wind tunnel results were observed with Strongblow and Topex-to-distance.For MC2, significant correlations were obtained at high windspeedsbut not at lower windspeeds. Ranking of windiness by topographicposition was identical for the wind tunnel, Strongblow and Topex-to-distance.Wind direction estimation by MC2 showed little sensitivity totopography, especially at higher windspeeds. This fact can beattributed both to the version of MC2 used and the conditionsin which the simulations were performed. The estimation of windspeedby direction obtained with Strongblow also appeared not to bevery reliable. The satisfactory performance of Topex-to-distanceand the ease with which this method can be calculated wouldmake it appropriate for inclusion in a windthrow hazard ratingsystem.