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41.
Antiserum был подготовлен противингибитор вируса haemagglutination (IVH)одна из эмбриона chorioallantoic мембр анныепутем иммун изации морских св инокЭто анти-инги битора в сыворотке заблокирован ингибирование IVH из chorioallantoicмембран в haemagglutination испытанияно ника кого влияния на ре цепторы эритроци товСыворотке кро] ви не влияет рост chorioallantoic мембраны клет ок инет нейтрализ овать воздействи е на вирус гриппа Она снизилась спо собность chorioallantoic мембр ан для adsorb вируса гри ппа, а также степен ь размножения вир усав такого рода тканиАвторы хоте ли бы поблагодари ть г-н Г. Ruttkay-Ne -палубе и для проведения эле ктрофореза меру ния. 相似文献
42.
Nefiracetam is a novel pyrrolidone derivative which attenuates scopolamine-induced learning and post-training consolidation
deficits. Given that apomorphine inhibits passive avoidance retention when given during training or in a defined 10–12h post-training
period, we evaluated the ability of nefiracetam to attenuate amnesia induced by dopaminergic agonism. A step-down passive
avoidance paradigm was employed and nefiracetam (3 mg/kg) and apomorphine (0.5 mg/kg) were given alone or in combination during
training and at the 10–12h post-training period of consolidation. Co-administration of nefiracetam and apomorphine during
training or 10h thereafter produced no significant anti-amnesic effect. However, administration of nefiracetam during training
completely reversed the amnesia induced by apomorphine at the 10h post-training time and the converse was also true. These
effects were not mediated by a dopaminergic mechanism as nefiracetam, at millimolar concentrations, failed to displace either
[3H]SCH 23390 or [3H]spiperone binding from D1 or D2 dopamine receptor subtypes, respectively. It is suggested that nefiracetam augments molecular processes in the early stages
of events which ultimately lead to consolidation of memory. 相似文献
43.
A research project on the population biology of ancient Etruscans has recently started. The aim of this multidisciplinary
research is the anthropological definition of Etruscan populations, about which little is known. The study of the skeletal
remains is expected to lead to the identification of characteristics typical of this group, which will be used to establish
affinities and differences with other contemporary Italic populations, as well as with previous and subsequent groups. An
outline of the project is presented here, together with an indication of the problems concerning the availability of material.
A summary of previous research on Etruscans is also given. In the final section, preliminary results are presented on one
aspect of the research presently under way, namely the odontometric study of different groups of Etruscan populations. These
results suggest a homogeneity within the groups described under the common label “Etruscans”. 相似文献
44.
D. de Beer V. O’Flaharty J. Thaveesri P. Lens W. Verstraete D. de Beer 《Applied microbiology and biotechnology》1996,46(2):197-201
Extracellular polysaccharides (EPS) were quantified in dense granules and loose flocs by chemical analysis of the uronic
acid content. Their distribution within the aggregates was determined by microscopic staining. Granules contained a higher
amount of EPS (1–1.6 mg/g volatile suspended solids, VSS) than flocs (0.3 mg/g VSS). In granules approximately 50% of the
total amount of EPS was present in a 40-μm-thick zone on the surface. The remainder was dispersed in the rest of the aggregate.
In flocs the highest concentration was present in the centre and the EPS layer on the surface was not found. Tests showed
that flocculent sludge was very sensitive to flotation, while the studied granules did not float. The lower susceptibility
to flotation of granules as compared to flocs was attributed to the presence of the hydrophilic EPS coating that prevents
attachment of gas bubbles.
Received: 21 November 1995/Received last revision: 15 April 1996/Accepted: 22 April 1996 相似文献
45.
Artificial nest predation and habitat fragmentation: different trends in bird and mammal predators 总被引:1,自引:0,他引:1
Predation on artificial nests was studied in Belgian deciduous forest fragments between 1 and 200 ha Predation rates were compared to fragment size, distance from the forest edge, time period (three replicates), and nest type (ground and tree) Logistic regression analysis showed that overall nest predation did not vary with distance from the edge, forest size, and time period Birds represented over 70% of all predator attacks but their importance decreased in larger areas and away from the forest edge where mammals were responsible for much of the nest predation It is concluded that the effect of habitat fragmentation depends on the composition of the local predator community 相似文献
46.
Sarah M. Nour John R. Lawrence Hong Zhu George D. W. Swerhone Martha Welsh Tom W. Welacky Edward Topp 《Applied microbiology》2003,69(1):607-615
The soybean cyst nematode (SCN), Heterodera glycines, causes economically significant damage to soybeans (Glycine max) in many parts of the world. The cysts of this nematode can remain quiescent in soils for many years as a reservoir of infection for future crops. To investigate bacterial communities associated with SCN cysts, cysts were obtained from eight SCN-infested farms in southern Ontario, Canada, and analyzed by culture-dependent and -independent means. Confocal laser scanning microscopy observations of cyst contents revealed a microbial flora located on the cyst exterior, within a polymer plug region and within the cyst. Microscopic counts using 5-(4,6-dichlorotriazine-2-yl)aminofluorescein staining and in situ hybridization (EUB 338) indicated that the cysts contained (2.6 ± 0.5) × 105 bacteria (mean ± standard deviation) with various cellular morphologies. Filamentous fungi were also observed. Live-dead staining indicated that the majority of cyst bacteria were viable. The probe Nile red also bound to the interior polymer, indicating that it is lipid rich in nature. Bacterial community profiles determined by denaturing gradient gel electrophoresis analysis were simple in composition. Bands shared by all eight samples included the actinobacterium genera Actinomadura and Streptomyces. A collection of 290 bacteria were obtained by plating macerated surface-sterilized cysts onto nutrient broth yeast extract agar or on actinomycete medium. These were clustered into groups of siblings by repetitive extragenic palindromic PCR fingerprinting, and representative isolates were tentatively identified on the basis of 16S rRNA gene sequence. Thirty phylotypes were detected, with the collection dominated by Lysobacter and Variovorax spp. This study has revealed the cysts of this important plant pathogen to be rich in a variety of bacteria, some of which could presumably play a role in the ecology of SCN or have potential as biocontrol agents. 相似文献
47.
P. Rizzu E. A. Lindsay C. Taylor H. O’Donnell A. Levy P. Scambler A. Baldini 《Mammalian genome》1996,7(9):639-643
We have identified and cloned a gene, ES2, encoding a putative 476 amino acid protein with a predicted M
r
of 52,568. The gene is localized within the DiGeorge/Velocardiofacial syndrome locus on 22q11.2 and is deleted in all the
patients in which a deletion within 22q11 could be demonstrated, with the exception of one patient. ES2 is expressed in all
the tissues studied. Sequence comparison showed identity with five ESTs and at the amino acid level the sequence was highly
similar to, and collinear with, a hypothetical C. elegans protein of unknown function. Mutation analysis was performed in 16 patients without deletion, but no mutation has been found.
The cDNA sequence is conserved in mouse and is localized on MMU16B1-B3, known to contain a syntenic group in common with HSA
22q11.2.
Received: 25 March 1996 / Accepted: 15 May 1996 相似文献
48.
49.
50.
Oligonucleotide primer-directed mutagenesis is a useful molecular biological tool, which is invalubable for the study of the structure/function relationships in proteins and for the creation of mutant proteins possessing modified or novel biological activities. Mutagenesis studies in which a site-saturation approach is employed require a high-efficiency mutagenesis procedure, which will generate a population of mutated molecules containing an even distribution of all possible amino acid changes, or a subset thereof. This article describes such a mutagenesis technique and discusses the adaptations that are necessary to perform sitesaturation mutagenesis. 相似文献