Process control and drug analysis with an on-line capillary electrophoresis system

Inorganic and organic ions in pulp and paper process waters and drug mixtures were studied. Real-time measurements and on-line simulated analyses were made. A novel on-line capillary electrophoresis instrument equipped with a fixed wavelength UV detector having a 254-nm filter was used for the analyses. Three dynamic sample and electrolyte micromodules provided on-line sampling, sample introduction and solution feedings. The system was used to monitor process samples containing thiosulphate, chloride, sulphate, oxalate, acetate and carbonate. It approved good performance in separation of ethacrynic acid, furosemide, probenecid, bumetanide and hydrochlorothiazide as well as that of normethanephrine, methanephrine and dopamine standard mixtures. The LOD and LOQ values of the ions and drugs ranged from 0.1 to 1 mg/l for LOD and from 1 to 10 mg/l for LOQ. Sensitivity of the drugs was higher due to the single wavelength available in the system. It required that the drugs were to be identified by indirect UV detection. Repeatability of the analyses was good (RSD% below 5).     

Changes in feeding level during early pregnancy affect fertility in gilts

Modified feeding combining the benefits of restricted feeding after ovulation and abundant feeding during implantation in autumn was tested. Three groups of eight gilts were housed with individual feeding stalls and fed 40 MJ per day of a commercial ration. Following insemination gilts were fed 27 MJ per day (LLL) or 54 MJ per day (HHH) for 34 days or 27 MJ per day for 10 days, 54 MJ per day for 7 days followed by 27 MJ per day until day 34 (LHL). Blood for progesterone analysis was collected daily during the week of ovulation and then twice a week until the end of the study. For LH assay, blood was collected from five gilts from each group at 15 min interval for 10 h on the day 15 of pregnancy. Gilts were weighed three times at intervals of 4 weeks. The effect of dietary treatment was significant (P<0.05) on body weight gain from days 0 to 30 of pregnancy, 1201, 287 and 438 g per day for groups HHH, LLL and LHL respectively. The pregnancy rate at day 34 was significantly higher (P<0.005) in HHH-group (100%) compared with LLL (25%) and LHL (38%) although HHH group had significantly lower (P<0.05) progesterone concentration on days 9 and 12. The basal LH level was significantly higher (P<0.01) in HHH group compared to LHL group (mean±S.D.) (0.98±0.22 and 0.60±0.08, respectively). Gilts in HHH group had a significantly higher mean LH concentration (1.18±0.24) than those in group LHL (0.7±0.07) (P<0.05), but not in group LLL (0.93±0.15) (P=0.09). There was a tendency (P=0.058) for amplitude to be higher for gilts in HHH group. The LHL feeding strategy did not provide the benefits anticipated. Instead, it was the HHH feeding strategy that provided a disfinct advantage in pregnancy rate. The mechanism mediating supportive effect of high feeding level on the maintenance of early pregnancy is yet to be determined.     

Preparation of 14C-labeled algal samples for liquid scintillation counting

Four commonly used techniques for preparation of ¹⁴C-labeled algal samples on membranes for liquid scintillation counting were compared and a simple technique for apparent net assimilation measurement from aqueous samples was introduced. All four techniques yielded similar radioactivities from the test cultures and are thus suitable for measurements of ¹⁴C algal samples. The possibly carcinogenic solvent dioxane was not necessary with PCS scintillation cocktail for dissolving radioactivity from algae on filters.     

Time-course of effects of toluene on microsomal enzymes in rat liver, kidney and lung during and after inhalation exposure

Inhalation of toluene vapour of 2000 ppm increased the activities of aniline hydroxylase, aminopyrine N-demethylase, aryl hydrocarbon hydroxylase and NADPH-cytochrome c reductase and the concentrations of cytochromes P-450 and b5 in liver microsomes of adult male rats after an exposure period of 1 day or less. Repeated treatments, 8 h daily for 1-16 days, had only a slight further effect. In lung microsomes, the activities of monooxygenases and the concentration of cytochrome P-450 decreased after 6-24 h toluene exposure, but those of cytochrome b5 and NADPH-cytochrome c reductase did not change. In kidney microsomes the changes were mostly insignificant. After discontinuation of exposure the activities of enzymes and the concentrations of cytochromes returned to the control level in 1-4 days. The results obtained resemble the time-courses for the induction of monooxygenases by other inducers. The tissue differences suggest the unequal distribution of various cytochrome P-450 forms and their individual responsiveness to induction in liver, kidneys and lungs.     

The expression and promoter specificity of the birch homologs for PISTILLATA/GLOBOSA and APETALA3/DEFICIENS

B-function genes determine the identity of petals and stamens in the flowers of model plants such as Arabidopsis and Antirrhinum . Here, we show that a putative B-function gene BpMADS2 , a birch homolog for PISTILLATA , is expressed in stamens and carpels of birch inflorescences. We also present a novel birch gene BpMADS8 , a homolog for APETALA3 / DEFICIENS , which is expressed in stamens. Promoter-GUS analysis revealed that BpMADS2 promoter is active in the receptacle of Arabidopsis flower buds while BpMADS8 promoter is highly specific in mature stamens. BpMADS2 promoter:: BARNASE construct prevented floral organ development in Arabidopsis and tobacco. In birch, inflorescences with degenerated stamens and carpels were obtained. BpMADS8::BARNASE resulted in degeneration of stamens in Arabidopsis and birch causing male sterility. In tobacco, only sepals were developed instead of normal flowers. The results show that the BpMADS2::BARNASE construct can be used to specifically disrupt floral organ development in phylogenetically distant plant species. The stamen-specific promoter of BpMADS8 is a promising tool for biotechnological applications in inducing male sterility or targeting gene expression in the late stamen development.     

Regional Eradication of Mycoplasma hyopneumoniae From Pig Herds and Documentation of Freedom of the Disease

The objectives of this study were to 1) screen all sow herds in a region for M. hyopneumoniae, 2) to effectuate an eradication programme in all those herds which were shown to be infected with M. hyopneumoniae, and 3) to follow the success of the screening and the eradication programmes. The ultimate goal was to eradicate M. hyopneumoniae from all member herds of a cooperative slaughterhouse (153 farrowing herds + 85 farrowing-to-finishing herds + 150 specialised finishing herds) before year 2000. During 1998 and 1999, a total of 5067 colostral whey and 755 serum samples (mean, 25 samples/herd) were collected from sow herds and analysed for antibodies to M. hyopneumoniae by ELISA. Antibodies were detected in 208 (3.6%) samples. Two farrowing herds (1.3%) and 20 farrowing-to-finishing herds (23.5%) were shown to be infected with M. hyopneumoniae. A programme to eradicate the infection from these herds was undertaken. During March 2000, a survey was made to prove the success of the screening and the eradication programmes. In total, 509 serum samples were collected randomly from slaughtered finishing pigs. Antibodies to M. hyopneumoniae were not detected in 506 of the samples, whereas 3 samples were considered suspicious or positive. Accordingly, 3 herds were shown to be infected. One of the herds was previously falsely classified as non-infected. Two of the herds were finishing herds practising continuous flow system (CF). Unlike finishing herds which practice all-in/all-out management routines on herd level, CF herds do not get rid of transmissible diseases spontaneously between batches, for which reason a screening was made in the rest of the CF herds (total n = 7). Consequently, 2 more infected herds were detected. In addition to the results of the survey, a decreasing prevalence of lung lesions at slaughter (from 5.2% to 0.1%) and lack of clinical breakdowns indicated that all member herds were finally free from M. hyopneumoniae in the end of year 2000.     

The role of molecular modelling and simulation in the discovery and deployment of metal-organic frameworks for gas storage and separation*

ABSTRACT

Metal-organic frameworks (MOFs) are highly tuneable, extended-network, crystalline, nanoporous materials with applications in gas storage, separations, and sensing. We review how molecular models and simulations of gas adsorption in MOFs have informed the discovery of performant MOFs for methane, hydrogen, and oxygen storage, xenon, carbon dioxide, and chemical warfare agent capture, and xylene enrichment. Particularly, we highlight how large, open databases of MOF crystal structures, post-processed to enable molecular simulations, are a platform for computational materials discovery. We discuss how to orient research efforts to routinise the computational discovery of MOFs for adsorption-based engineering applications.     

Distribution of the major histocompatibility complex antigens on different cellular components of human liver

Monoclonal mouse antibodies to the "framework" determinants of the class I and II molecules of the major histocompatibility complex (MHC) were used to demonstrate the presence of the MHC antigens in human liver. First, the localization of these antigens was demonstrated from frozen section histology with indirect FITC immunofluorescence and the cell component(s) binding the mouse antibody were identified by rabbit marker antisera and indirect TRITC immunofluorescence. Second, the antigen expression on the cell surface was analyzed by the Staphylococcus aureus rosette method from cytological cell smears. All antibodies reacted with cells in the liver sinusoids, both with the Kupffer cells and at least partially with the sinusoidal endothelial cells. The same antisera reacted also with the bile duct cells, though weaker, and with some stromal cells in close proximity of the blood vessels. The vascular endothelial cells of hepatic artery, hepatic vein, and portal vein displayed no reaction. Thus human liver differs strikingly from, e.g., human kidney, where the vascular endothelial cells contain large amounts of MHC antigens on the cell surface. This difference may be one explanation to why liver allografts are less promptly rejected than renal allografts in man.     

Conservation of vascular plants in single large and several small mires: species richness, rarity and taxonomic diversity

1. This study on vascular plant species of boreal spruce and pine mires concentrated on two geometrical principles: whether single large or several small (SLOSS) reserves contain more species and whether patch shape should be as nearly circular as possible.
2. SLOSS and patch shape have usually been tested by using species richness. Only a few studies have taken the rarity of species into account, and taxonomic diversity has never been used. In our study, all three of these factors were used.
3. Our results showed that the number of species was not related to the spruce mire size, but it increased in relation to the pine mire size. In contrast, the rarity score increased in relation to the area of spruce mires, but it was not related to the area of pine mires. Taxonomic diversity was not related to size in the case of spruce mires, but it increased with pine mires.
4. The SLOSS comparison showed that several small mires contained more vascular plant species than a large one of equal size. Several small mires also had higher rarity scores and taxonomic diversity than a single large mire. The number of species, rarity score and taxonomic diversity increased in relation to the number of small mires in a group. The same results were obtained with both spruce and pine mires.
5. Species richness, rarity score and taxonomic diversity were not related to mire shape. The results did not depend on the mire type.