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1.
Strains of [Actinobacillus] rossii, [Pasteurella] mairii and [Pasteurella] aerogenes can be isolated from abortion in swine. The RTX toxin Pax has previously been found only in those [P.] aerogenes strains isolated from abortion. Nothing is known about RTX toxins in field isolates of the other two species. To gain insight into the distribution of selected RTX toxin genes and their association with abortion, PCR screening for the pax, apxII and apxIII operons on 21 [A.] rossii and seven [P.] mairii isolates was done. Since species can be phenotypically misidentified, the study was backed up by a phylogenetic analysis of all strains based on 16S rRNA, rpoB and infB genes. The pax gene was detected in all [P.] mairii but not in [A.] rossii strains. No apx genes were found in [P.] mairii but different gene combinations for apx were detected in [A.] rossii strains. Most of these strains were positive for apxIII, either alone or in combination with apxII. Whereas pax was found to be associated to strains from abortion no such indication could be found with apx in [A.] rossii strains. Phylogenetically [A.] rossii strains formed a heterogeneous cluster separated from Actinobacillus sensu stricto. [P.] mairii strains clustered with [P.] aerogenes but forming a separate branch. The fact that [P.] aerogenes, [P.] mairii and [A.] rossii can phylogenetically clearly be identified and might contain distinct RTX toxin genes allows their proper diagnosis and will further help to investigate their role as pathogens.  相似文献   
2.
Journal of Soils and Sediments - The objective of this study was to evaluate the mutual relations between the soil organic matter (SOM) fractions: fulvic acids (FA), humic acids (HA), humins (HN),...  相似文献   
3.
The sites of oestrogen action can be shown by the localisation of their receptors in the target tissues. The aim of the present study was to show the localisation of oestrogen receptors in porcine embryos and fetuses obtained on days 18, 22, 32, 40, 50, 60, 71 and 90 post coitum (p.c.). The visualisation of proteins was conducted in embryos and various fetal organs such as gonads, uterus, lung, kidney, intestine and adrenal gland. Both ERs were observed in the blastocysts on day 18 p.c. In the male, ERbeta was detected in the testis and epididymis, whereas ERalpha was present in the efferent ductules. In the female, ERbeta was detected in the ovarian stromal cells investing the oocyte nests, while ERalpha protein was detected in the surface epithelium. In the uterus, ERs were present in the stromal cells, while ERbeta was present in the luminal epithelium. In the non-reproductive fetal porcine tissues ERbeta was localised in the lungs, kidneys, adrenal glands and in the umbilical cords. Both ERs were observed in the intestine. It is possible that ERbeta may play important roles in the development of the adrenal gland, testis, kidney and lungs, while both ERs are involved in the development of the ovary, uterus, epididymis and intestine of the porcine fetus.  相似文献   
4.
A field trial was conducted in 1994 to determine the foliar deposit of tebufenozide (RH5992), applied aerially, and its efficacy against spruce budworm, Choristoneura fumiferana (Clem.). A commercial 240 g litre-1 formulation of the insecticide (Mimic 240LV) was mixed with water, dyed with a tracer dye (Rhodamine WT) and sprayed with a light fixed-wing aircraft. Six application strategies were tested. Five used 70 g AI ha-1 in a spray volume of 1 or 2 litre-1 ha-1 with single or double applications; the sixth was an unsprayed control. Results show that the spectra of the spray applications were, with one exception, fairly uniform. Volume and number median diameters ranged from 100 to 130 μm and 27 to 72 μm, respectively. Mean number of drops cm-2 on Kromekote cards were <2·0 for strategies where either 1 or 2 litre ha-1 were sprayed. Nevertheless no one strategy produced droplet densities that were significantly different (P<0·05) from the other strategies. Tebufenozide recovered from foliage averaged 2·5 to 5·9 μg g foliage-1 when 1 litre ha-1 was sprayed and 5·8 to 6·8 μg g foliage-1 after 2 litre ha-1 were sprayed. When a single application was the strategy used, the mean number of droplets cm-2 and μg tebufenozide g foliage-1 ranged from 1·2 to 1·4 and 2·5 to 5·9, respectively. With double applications, the same response parameters ranged from 0·3 to 1·9 and 2·5 to 6·8, respectively. Budworm population reductions (%) and the number of larvae that survived tebufenozide treatments were significantly different (P<0·05) from the controls. After strategies that used 1 litre spray ha-1, mean percentage population reductions ranged from 61·4 to 93·6 whereas populations were reduced by 85·6 to 98·3% when 2 litre ha-1 were sprayed. After double applications the mean percentage population reductions ranged from 93·6 to 98·3, but single application strategies resulted in mean reductions of 61 to 86%. Mean population reductions in the controls were 61%. The mean number of larvae per branch that survived spray strategies of 1 litre ha-1 ranged from 1·3 to 7·4, and from 0·4 to 1·3 when 2 litre ha-1 was the spray volume. In the controls an average of 10·2 larvae survived. With one exception, mean percentage defoliation in the treated areas was also significantly less (P<0·05) than that in the control. Mean defoliation in trees sprayed at 1 litre spray ha-1 ranged from 40 to 62·8% whereas those treated at 2 litre ha-1 had mean defoliation levels from 31·5 to 62·8%. In contrast, average defoliation in the controls was 92·1%. When a single application was the spray strategy, mean defoliation ranged from 31·5 to 62·8%. These data imply that a double application of tebufenozide at 70 g in 2 litre ha-1 was the most efficacious strategy. However, analyses of the data also show that the primary influence on deposits and defoliation was interactions between number of applications and spray. Nevertheless the two independent variables acted without significant interactions when influencing percentage reductions of spruce budworm populations. © 1998 SCI  相似文献   
5.
Mycoplasma mycoides subsp. capri and Mycoplasma mycoides subsp. mycoides LC can be combined into one taxon on the basis of several contributions on both DNA sequence and protein analyses reported in the literature. Moreover, for the differentiation and identification of mycoplasmas of the "mycoides cluster", we investigated the rpoB gene, encoding the beta-subunit of the RNA polymerase. A segment of 527 bp of the rpoB gene was amplified from 31 strains of ruminant mycoplasmas by PCR. The nucleotide sequences were determined and aligned, and accurate genetic relationships were calculated. Cluster analysis of rpoB DNA allowed species differentiation within the "mycoides cluster" and confirmed that M. mycoides subsp. capri and M. mycoides subsp. mycoides LC cannot be distinguished from each other. "Mycoplasma mycoides subsp. capri" is proposed as a common name for both subspecies.  相似文献   
6.
We analyzed the DNA content of hepatocyte and erythrocyte nuclei of the spined loach Cobitis taenia (diploid) and its allopolyploid forms. Twenty triploid females and one tetraploid were used. At least 20,000 hepatocyte and erythrocyte nuclei were acquired and analyzed by flow cytometry. C. taenia erythrocyte nuclei contain 3.15 ± 0.21 pg of DNA and the hepatocyte nuclei 4.45 ± 0.46 pg of DNA. Triploid Cobitis have 5.08 ± 0.41 pg of DNA in erythrocyte nuclei and 6.11 ± 0.40 pg of DNA in hepatocyte nuclei, whereas the tetraploid erythrocyte and hepatocyte nuclei contained 6.60 and 7.40 pg of DNA, respectively. In general, the DNA contents correlate positively with the ploidy level of the fish investigated. The DNA content variation in the hepatocyte and erythrocyte nuclei may be due to differences in extent of chromatin condensation, which is more pronounced in the erythrocyte than hepatocyte nuclei, or to the several orders of ploidy that occur in the parenchymal liver cells.  相似文献   
7.
测定了利木赞×娟姗牛杂交一代3头公牛所有回交后代的背最长肌和半腱肌的剪切力、pH值及煮 制损失3个表型性状,与已构建的遗传连锁图谱和基因型值相结合,利用QTL Express软件的“Half-Sib QTL Analysis Servlet”进行QTL分析。共发现6个可能的QTL位点,其中背最长肌剪切力性状3个QTL(BTA2 45 cM,BTA29 54 cM)、半腱肌剪切力1个QTL(BTA2 12 cM)、半腱肌pH值1个QTL(BTA24 0 cM)、背最长肌 煮制损失1个QTL(BTA142 cM)。  相似文献   
8.
During the intensive flood in May–June 2010, the floodplains in Little Poland Vistula Gap, used mostly for agriculture, were waterlogged for a period of over 1 month. The aim of the study was to assess the effect of the flood on the level of contamination of the soils in this region. The analysis included basic physicochemical soil properties, contents of ten metals, and concentrations of 16 polycyclic aromatic hydrocarbons (PAHs). The studies cover two territories on opposite sites of the river Vistula (Wilkow and Janowiec) differing in their areas (70 and 4.6 km2) and time of water logging (30 and 10 days). Forty soil samples were collected from both areas immediately after the flood event from the upper (0–30 cm) soil layer together with four samples from the 30–60-cm depth layer. This was supplemented by eight samples from the flood-deposited sediment layer (thickness, 2 cm). The concentrations of identified metals (As, Ba, Cr, Sn, Zn, Cd, Co, Cu, Ni, Pb) at all the sampling points were below the Polish legal limits for the upper layer of soils for agriculture use. The same regarded the median contents of nine PAHs compounds specified in the Polish regulations. In both areas, the median contents of Σ16 PAHs (0.21–0.35 mg kg−1), Zn (10.3–10.6 mg kg−1), Pb (9.2–10.7 mg kg−1), and Cd (0.03 mg kg−1) were much below the mean concentrations of those contaminants in arable soils on the national and European levels. The results show that this severe flooding episode in “clean” agricultural area had no immediate negative impact on the soils as regards the basic physicochemical properties (organic matter content, acidity, nitrogen content) and did not result in excessive soil contamination.  相似文献   
9.
A multilocus sequence typing (MLST) scheme was established and evaluated for Mycoplasma hyopneumoniae, the etiologic agent of enzootic pneumonia in swine with the aim of defining strains. Putative target genes were selected by genome sequence comparisons. Out of 12 housekeeping genes chosen and experimentally validated, the 7 genes efp, metG, pgiB, recA, adk, rpoB, and tpiA were finally used to establish the MLST scheme. Their usefulness was assessed individually and in combination using a set of well-defined field samples and strains of M. hyopneumoniae. A reduction to the three targets showing highest variation (adk, rpoB, and tpiA) was possible resulting in the same number of sequence types as using the seven targets. The established MLST approach was compared with the recently described typing method using the serine-rich repeat motif-encoding region of the p146 gene. There was coherence between the two methods, but MLST resulted in a slightly higher resolution. Farms recognized to be affected by enzootic pneumonia were always associated with a single M. hyopneumoniae clone, which in most cases differed from farm to farm. However, farms in close geographic or operational contact showed identical clones as defined by MLST typing. Population analysis showed that recombination in M. hyopneumoniae occurs and that strains are very diverse with only limited clonality observed. Elaborate classical MLST schemes using multiple targets for M. hyopneumoniae might therefore be of limited value. In contrast, MLST typing of M. hyopneumoniae using the three genes adk, rpoB, and tpiA seems to be sufficient for epidemiological investigations by direct amplification of target genes from lysate of clinical material without prior cultivation.  相似文献   
10.
Francisella tularensis, a small Gram-negative facultative intracellular bacterium, is the causative agent of tularaemia, a severe zoonotic disease transmitted to humans mostly by vectors such as ticks, flies and mosquitoes. The disease is endemic in many parts of the northern hemisphere. Among animals, the most affected species belong to rodents and lagomorphs, in particular hares. However, in the recent years, many cases of tularaemia among small monkeys in zoos were reported. We have developed a real-time PCR that allows to quantify F. tularensis in tissue samples. Using this method, we identified the spleen and the kidney as the most heavily infected organ containing up to 400 F. tularensis bacteria per simian host cell in two common squirrel monkeys (Saimiri sciureus) from a zoo that died of tularaemia. In other organs such as the brain, F. tularensis was detected at much lower titres. The strain that caused the infection was identified as F. tularensis subsp. holarctica biovar I, which is susceptible to erythromycin. The high number of F. tularensis present in soft organs such as spleen, liver and kidney represents a high risk for persons handling such carcasses and explains the transmission of the disease to a pathologist during post-mortem analysis. Herein, we show that real-time PCR allows a reliable and rapid diagnosis of F. tularensis directly from tissue samples of infected animals, which is crucial in order to attempt accurate prophylactic measures, especially in cases where humans or other animals have been exposed to this highly contagious pathogen.  相似文献   
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