聚酰亚胺的改性

本文介绍了旨在克服聚酰亚胺某些性能缺陷的改性产品 ,其中包括可溶型、透明型、低热膨胀型、共缩聚型、功能型、高粘接型、加成型聚酰亚胺和聚酰亚胺 /无机纳米复合材料等品种的研究动向 ,指出目前应重点研究聚酰亚胺 /无机纳米复合材料     

Thyroid hormones in dairy calves after birth and in the first days of life. Amplitude of variation, maternal-fetal relationships and reaction patterns specific to the individual

Dairy calves and their dams from the dairy herd of the institute were used for this investigation. Calvings were watch carefully and jugular venous blood samples taken immediately after delivery from the cow and the calf and in the calf at 24 hours and at 48 hours of postnatal age as well were analyzed for T4, FT4, T3 and FT3 by luminescence enzyme immunoassay (LEIA). Higher thyroid values in calves than in their dams could be found increasing short after birth and reaching their highest level within 24 hours of postnatal life. The individual thyroid hormone values at birth and at 24 hours and at 48 hours of age are well correlated meaning the changes during the first days are specific for each calf. Strong correlation between the thyroid hormone values of the cows and those of the calves could be found. Mean values of thyroid hormones were significantly higher in female than in male calves all time but not different in the dams of these calves.     

An automated data acquisition system for modeling thecharacteristics of a soil moisture sensor

Population growth results in an increasing demand on water supply. Usually, growers determine how much water is needed to irrigate their fields on the basis of the amount of time elapsed since the last irrigation cycle. A soil moisture sensor enables the users (or an automated irrigation system) to monitor the relative soil moisture constantly at many different locations throughout the field in order to schedule irrigation cycles more precisely. An automated data acquisition system for measuring the characteristics of a soil moisture sensor under various moisture conditions is presented. Based on the measurement data, an empirical model for the soil moisture sensor is also developed. A comparison of the model and experimental data is included     

Application of nested PCR and mass spectrometry for DNA-based virus detection: HBV-DNA detected in the majority of isolated anti-HBc positive sera

DNA preparations from three different groups of serum samples were examined for HBV-DNA via a nested polymerase chain reaction assay (lower detection limit: 10 viral genomes in 100 microliters serum): Group I consisted of 11 uninfected control sera, group II consisted of sera obtained from 11 HBV infected patients and group III consisted of 21 isolated anti-HBc positive samples. The 21 samples from group III were HBV-DNA negative according to a conventional non-nested PCR assay and hybridization with a 32P-labelled probe. Using nested PCR and mass spectrometry, HBV-DNA was detected in none of group I and in all of group II samples. In 11 out of 21 (52%) of the isolated anti-HBc positive sera from group III, HBV-DNA was detected. No correlation was observed between HBV-DNA positivity and anti-HBc titers. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry provided a fast, sensitive and non-radioactive assay for the detection of PCR products without the need for gel electrophoresis or hybridization with labelled probes.