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21.
Length changes of autoclaved aerated concrete due to moisture variations have been investigated by tests on a Danish brand of autoclaved aerated concrete. The investigation have shown that autoclaved aerated concrete with delivery moisture content exhibits swelling when initially conditioned at relative humidities above 43%, whereas initial conditioning below 43% relative humidity leads to shrinkage. After the initial conditioning has been performed, length changes are shown to be almost proportional to the variation in relative humidity. The investigation has shown that the present Danish Standard in this area is misleading, and the principle of a new NORDTEST method, NT Build 444(1996), is presented, Furthermore this test method is compared with the European Standard EN 680,Determination of the drying shrinkage of autoclaved aerated concrete, and a draft for another European Standard prEN 772-12:1992,Determination of length change during moisture movements in autoclaved aerated concrete masonry units. 相似文献
22.
Prevalence and diversity of Campylobacter jejuni in pig herds on farms with and without cattle or poultry 总被引:2,自引:0,他引:2
Boes J Nersting L Nielsen EM Kranker S Enøe C Wachmann HC Baggesen DL 《Journal of food protection》2005,68(4):722-727
The prevalence and diversity of Campylobacter jejuni was investigated in pig herds on farms with and without cattle or poultry production. A bacteriological screening of pig cecal samples from 247 finisher herds was carried out at the slaughter-house. Subsequently, a follow-up study was conducted in 24 herds (either with or without prior C. jejuni isolation from pigs) in which fecal samples were collected from pigs and, if present, cattle and poultry. Samples were analyzed for presence of Campylobacter, and subsequent analysis included species identification, serotyping, and, for selected strains, pulsed-field gel electrophoresis typing. In the slaughterhouse screening, C. jejuni was isolated from pigs in 21 (8.5%) herds, but no significant difference in prevalence was found between herd types (pigs, pigs and cattle, pigs and poultry). At the slaughterhouse, C. jejuni and Campylobacter coli prevalence in pigs was 2.3 and 90.1%, respectively. In the follow-up study, herd prevalence of C. jejuni was 8.3%, whereas C. jejuni and C. coli were isolated from 0.8 and 92.0% of pigs, respectively. In mixed production herds, C. jejuni predominated in cattle (42.7%) and poultry (31.6%), whereas C. jejuni was only isolated from 1.3 to 2.5% of pigs in these herds. There were no significant differences in C. jejuni or C. coli prevalence in pigs, cattle, and poultry between herds with and without prior C. jejuni isolation at the slaughterhouse. Pulsed-field gel electrophoresis typing did not yield evidence of C. jejuni transmission between cattle or poultry and pigs in mixed production herds. In contrast, pulsed-field gel electrophoresis analysis showed indistinguishable serotypes of C. coli in pigs and cattle in two herds. Verification of C. jejuni-positive pig samples showed that individual pigs can excrete high levels of C. jejuni and that mixed infection with C. jejuni and C. coli was common in C. jejuni-positive pigs. The results of our study suggest that transmission of C. jejuni between pigs and cattle or poultry in mixed production herds occurs infrequently. Detection of indistinguishable C. coli isolates in two herds, however, might indicate the existence of low-level transmission between pigs and cattle in herds of mixed production. 相似文献
23.
M. Mansouryar H. Mirzaei-Alamouti M. Dehghan Banadaky H. Sauerwein M. Mielenz M.O. Nielsen 《Journal of dairy science》2018,101(9):8552-8558
We hypothesized that plasma adipokine concentrations of early-lactation dairy cows are related to body condition score (BCS) at calving and to markers of metabolic status of the cow. As part of a larger study with 117 multiparous Holstein dairy cows, which had high BCS (BCS >4.0) or normal BCS (3.25–3.5) at calving, 22 cows were randomly selected (n = 11 per group) to be enrolled in this study. Cows were divided into 2 groups based on their BCS at calving: (1) normal BCS with BCS of 3.35 ± 0.13 (mean ± SD) and (2) high BCS cows with BCS of 4.14 ± 0.17. The 22 selected animals did not have a clinically diagnosed health problem after calving. Blood samples were taken right after calving (d 1) and before morning feeding on d 8, 15, and 21 postpartum concurrently with body condition scoring for all cows. Blood samples were analyzed for plasma adiponectin, leptin, tumor necrosis factor-α, and IL-6. The mean BCS remained highest in high-BCS cows during the first 21 d in milk. Leptin concentrations decreased progressively for all cows after calving. However, differences in BCS at calving were not related to leptin concentrations. Adiponectin, IL-6, and tumor necrosis factor-α concentrations were neither influenced by days in milk nor BCS after calving. Leptin and the leptin-to-adiponectin ratio did not show any correlation at any time point during the first 21 d in milk with plasma concentrations of nonesterified fatty acids or β-hydroxybutyrate, which are considered as markers of metabolic status. Only for IL-6 at d 8 did we find a strong correlation with metabolic status indicators. In conclusion, plasma adipokine concentrations during the first 3 wk postpartum were not related to BCS in lactating Holstein cows that were clinically healthy at calving. 相似文献
24.
F Ramirez JV O'Donnell PA Marks A Bank S Musumeci G Schilirò G Pizzarelli G Russo B Luppis R Gambino 《Canadian Metallurgical Quarterly》1976,263(5577):471-475
In patients with betao thalassaemia from Ferrara, beta globin mRNA sequences are either absent or structurally abnormal while in betao thalassaemia in Catania, beta globin mRNA sequences are present. In deltabeta thalassaemia there is a deletion of beta-like globin genes, while in betao Catania DNA, no beta globin gene deletion is detectable. 相似文献
25.
26.
Report is given on a metabolic investigation with non-radioactive and 14C-labelled methiothepin(1-[10',11'-dihydro-8'-(methylthio)-dibenzo mean value of b,f thiepin-10'yl]-4-methyl-piperazine) in rat, dog, and man. After i.p. and oral administration of the drug to the rat, the metabolites of methiothepin were excreted fecally. In the same species, a considerable biliary secretion of the compounds has been demonstrated. In dog and in man, excreted metabolites have been found both in urine and feces after oral application of the drug. The biotransformation of methiothepin within the species investigated proceeds via hydroxylation, sulfoxidation, O-methylation, N-demethylation, N-oxidation and formation of conjugates. The large number of metabolites is due to the various sites of action within the molecule, that are accessible to in vivo oxidation. Of a large number of isolated positionally isomeric compounds, merely the basal structures could be clarified. Possibly the mode of biotransformation to which methiothepin is subjected in the organism, proves determinant for the way of excretion. In the rat, all metabolites are hydroxylated and reach the intestinal tract as conjugates with the bile. In dog and man, however, non-hydroxylated, sulfoxidized metabolites were likewise found, which were excreted mainly renally in both species. 相似文献
27.
1. Using the technique of density-labelling with deuterium oxide, evidence has been obtained for the de novo synthesis of glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NADPH+ 1-oxidoreductase, EC 1.1.1.49), during the culture of synchronously growing plant cells. 2. The entire increase in enzyme activity during the early cell cycles in this material can be accounted for by the appearance of an enzyme species with increased buoyand density. 3. A method is described for resolving overlapping distribution profiles after density centrifugation, which allows estimation of the amount of each species present at different times, and calculation of the loss of activity of the light species present from the start of culture. 4. Loss of activity of glucose-6-phosphate dehydrogenase in normal growing conditions in the presence of 2,4-dichlorophenoxyacetic acid is very much faster than in conditions which do not lead to cell division: in the absence of 2,4-dichlorophenoxyacetic acid, or in the presence of the inhibitor of RNA synthesis, 6-methylpurine. 相似文献
28.
DG Skinner JB Dekernion PA Brower KP Ramming YH Pilch 《Canadian Metallurgical Quarterly》1976,115(3):246-250
Herein we describe the first clinical treatment of renal cell carcinoma in humans with xenogeneic immune ribonucleic acid. Twelve patients with advanced renal cell carcinoma have been treated by appropriate operations to remove tumor bulk followed by specific passive immunotherapy. Xenogeneic specific immune ribonucleic acid was prepared from the spleen of normal sheep that had received 4 weekly injections of a homogenate of renal cell carcinoma. Results indicate that 1) xenogeneic specific immune ribonucleic acid can safely be given to humans without local or systemic toxicity, 2) there is a suggestion of clinical benefit, since only 2 patients have had progression of known metastases during treatment with immune ribonucleic acid and 3) xenogeneic immune ribonucleic acid can enhance the immune response to renal cell carcinoma, as demonstrated by in vitro lymphocytoxicity tests. 相似文献
29.
Morphological and physiological studies were made on chicken cecal isolates of the strictly anaerobic bacterial species Gemmiger formicilis. Structural features (phase-contrast and electron microscopy) of these microorganisms indicate they (i) are highly pleomorphic, (ii) possess a trilaminar cell wall like gram-negative bacteria, (iii) exhibit an unusual growth process characterized by polar swelling (resembling budding bacteria), and (iv) grow into elongated cells when exposed to a subinhibitory concentration of penicillin. The morphological data presented suggest that this species has a rod-shaped structure. These bacteria ferment a variety of sugars to produce formic, butyric, and lactic acids. There appear to be two groups of Gemmiger, one producing primarily lactate and the other producing formate as major fermentation metabolites. Growth of six strains in a basal medium, consisting of Trypticase, minerals, carbohydrate, Na2CO3 buffer, and cysteine as reducing agent, was stimulated by rumen fluid and yeast extract. Volatile fatty acids partially replaced the requirement for rumen fluid with some strains. Single deletions of vitamins (from a defined vitamin mixture) indicated that pantothenate, riboflavin, and thiamine were highly stimulatory to growth of the organism in a medium containing rumen fluid and Trypticase as source of vitamins. Other vitamin requirements were not studied. 相似文献
30.
Side effects of orally administered bismuthic salts have been known for many years. Many systems are involved, including the digestive and urinary. The authors discuss a recently discovered effect on the central nervous system, termed "bismuth encephalopathy". In the light of the medical literature reviewed, two original aspects are stressed: the clinical symptoms are stereotyped and completely reversible, and the distribution of the disease is almost epidemic, being limited in time and space. The prodromes include confusion, asthenia, slowing of mental functions and disturbance of gait. The clinical picture is dominated by four major symptoms: confusion (again), ataxia, dysarthria and, above all, myoclonic jerks. In conclusion, various pathogenetic hypotheses are considered. The purpose of this study is to enable the general practitioner to detect the development of this condition early in treatment with oral bismuthic salts. Withdrawal of the medication always results in normalization of the patient's condition. 相似文献