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1.
By means of standardized procedures, the metabolism of [ring-2,6-14C]-parathion was investigated in carrot (Daucus carota L.), purple foxglove (Digitalis purpurea L.), soybean (Glycine max Merrill cv. ?Mandarin’?, and Glycine max Merrill cv. ?Harosoy 63’? cultivated on B5 and Miller media, respectively), thorn apple (Datura stramonium L.), and wheat (Triticum aestivum L.) cell suspension cultures. In the wheat and soybean (Mandarin) cells only 2.9 and 8.9%, respectively, of the applied parthion remained unmetabolized after 48 h of incubation, while 51.2, 57.9, 60.3, and 62.4% of the unchanged parent were detected in the D. purpurea, D. Stramonium, carrot and soybean (Harosoy) cultures, respectively. In all suspensions, paraoxon and 4-nitrophenol were found as phase I metabolites, thus demonstrating that plant tissues can catalyse oxidative desulfuration and dearylation of parathion. 4-Nitrophenol was also glycosylated with glucose and possibly galactose. Further, as yet unidentified, metabolites indicated that bio-transformations had also occurred at the aromatic moiety. Large amounts of non-extractable residues were detected in the wheat suspension (38.3%), while the other cultures showed a lower incorporation of 14C into insoluble cell material (0.9-9.4%). For a prospective ecotoxicological evaluation of the metabolic fate of pesticides and xenobiotics in plants in general, the differential metabolic capacity of plant cell cultures and plants should be taken into account.  相似文献   
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The oxidizing capacity of the global atmosphere is largely determined by hydroxyl (OH) radicals and is diagnosed by analyzing methyl chloroform (CH(3)CCl(3)) measurements. Previously, large year-to-year changes in global mean OH concentrations have been inferred from such measurements, suggesting that the atmospheric oxidizing capacity is sensitive to perturbations by widespread air pollution and natural influences. We show how the interannual variability in OH has been more precisely estimated from CH(3)CCl(3) measurements since 1998, when atmospheric gradients of CH(3)CCl(3) had diminished as a result of the Montreal Protocol. We infer a small interannual OH variability as a result, indicating that global OH is generally well buffered against perturbations. This small variability is consistent with measurements of methane and other trace gases oxidized primarily by OH, as well as global photochemical model calculations.  相似文献   
4.
Tracheal cytotoxin (TCT), a naturally occurring fragment of Gram-negative peptidoglycan, is a potent elicitor of innate immune responses in Drosophila. It induces the heterodimerization of its recognition receptors, the peptidoglycan recognition proteins (PGRPs) LCa and LCx, which activates the immune deficiency pathway. The crystal structure at 2.1 angstrom resolution of TCT in complex with the ectodomains of PGRP-LCa and PGRP-LCx shows that TCT is bound to and presented by the LCx ectodomain for recognition by the LCa ectodomain; the latter lacks a canonical peptidoglycan-docking groove conserved in other PGRPs. The interface, revealed in atomic detail, between TCT and the receptor complex highlights the importance of the anhydro-containing disaccharide in bridging the two ectodomains together and the critical role of diaminopimelic acid as the specificity determinant for PGRP interaction.  相似文献   
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Dothistroma needle blight (DNB) has been observed in Slovakia during the last two decades. Up until 2017, Dothistroma septosporum has only been detected and molecularly confirmed to cause DNB in Slovakia. Here, we report the detection of Dothistroma pini at six localities around Slovakia, representing different plantation types. Four pine species (Pinus sylvestris, P. nigra, P. mugo and P. jeffreyi) were confirmed as hosts of D. pini in Slovakia, of which only P. mugo has been previously reported as host in Slovakia. Three gene regions (ITS, EF1 –α, and ß-tubulin) of each of the 13 isolates were sequenced and assigned as D. pini. Based on ITS sequences, the studied isolates represent the haplotypes Dp_HAP.1, Dp_HAP.2. Both mating types were detected but at different localities. Our results suggest that in addition to D. septosporum, D. pini may contribute to DNB also in Slovakia.  相似文献   
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Hepatitis E virus is a major causative agent of acute hepatitis worldwide. Despite its zoonotic potential, there is limited information about the natural chain of hepevirus infection in wildlife, and the potential reservoir species. In this study, we performed a HEV survey by heminested RT‐PCR on rodent samples from an urban environment (in the city of Pécs, Hungary) and investigated the prevalence of the virus among these native rodent species (Apodemus agrarius, Apodemus flavicollis, Apodemus sylvaticus, Microtus arvalis and Myodes glareolus). HEV was detected exclusively in Common voles (M. arvalis), in 10.2% of screened voles, and 3.2% of all investigated samples from all species. Based on the phylogenetic analysis, our strain showed the closest homology with European Orthohepevirus C strains detected previously in faecal samples of birds of prey and Red fox, supporting the possibility of the dietary origin of these strains. In addition, our samples showed close phylogenetic relation with a South American strain detected in Necromys lasiurus (Cricetidae), but separated clearly from other Muridae‐associated strains, suggesting the presence of a Cricetidae‐specific genotype in Europe and South‐America. Based on these results, we hypothesize the reservoir role of M. arvalis rodents for the European Cricetidae‐specific Orthohepevirus C genotype.  相似文献   
8.
The jejunal and medial iliac lymph nodes of 53 clinically normal dogs between the age of 4 and 6 weeks were examined ultrasonographically. At least two jejunal and both left and right medial iliac lymph nodes were seen in all dogs. One hundred forty‐five jejunal, 53 right medial iliac and 53 left medial iliac lymph nodes in six litters of dogs, for a total of 251 lymph nodes, were measured for cross sectional maximum diameters. Mean jejunal lymph node length was 16.4 mm (range 6.4–34.9 mm) and mean width was 6.0 mm (range 2.3–15.7 mm). The mean medial iliac lymph node length was 13.6 mm (range 7.2–27.8 mm) and mean width was 4.4 mm (range 1.9–8.2 mm). Significant differences of lymph node size, noted between and within breeds, may not be of clinical significance. The mean size of the combined left and right medial iliac nodes was within previously published ranges for normal adult dogs. Lymph nodes were described in four litters of dogs (162 lymph nodes). Lymph nodes were either uniformly hypoechoic (108/163, 66%) or centrally hyperechoic with a hypoechoic rim (55/163, 34%). Although most (60%) lymph nodes were oval, a variety of shapes were seen, including vermiform and complex branching shapes. We concluded that in 4‐ to 6‐week‐old dogs, medial iliac lymph nodes are similar in size to adult dogs and jejunal lymph nodes are multiple, routinely seen, are larger than in adults and often have unconventional shapes.  相似文献   
9.
The aim of the study was to analyze the factors creating consumer attributes of roasted beef steaks of various animals. Eight cuts from 30 carcasses (characterized by various types of animal, conformation and fat class, rib fat thickness, ossification score) were selected. Samples were prepared using the roasting method and consumers rated the tenderness, juiciness, flavor, overall acceptability (rated in a 100‐point scale), and satisfaction (rated from 2 to 5) for analyzed samples. No influence of type of animal, fat class, conformation class or ossification score on the results of consumer analysis was observed. For all analyzed factors, the influence of cut on consumer analysis was observed (the highest values of all consumer attributes were observed for tenderloin ‐ for juiciness significantly higher than for other cuts, for tenderness, flavor and MQ4 comparable only with rump (RMP231), while for overall acceptability and satisfaction – with both rump cuts). For rib fat thickness consumer attributes of roasted beef meat were not linear, but the influence was observed – the highest values of consumer attributes were observed for 13 mm rib fat thickness.  相似文献   
10.

Purpose

The study aimed at comparing organic matter decomposition in two semi-natural agrobiocenozes, namely fallows and meadows, with similar plant biomass but differing in plant community composition and diversity and in succession stage.

Materials and methods

The decomposition rate of a standard material (cellulose) was measured in soils from six fallows and six meadows spanning a few kilometres apart. The mathematical model was fitted to the data.

Results and discussion

The model showed a significantly longer lag-time in cellulose decomposition in the meadows. Despite the delayed start of decomposition in the meadows, the estimated decomposition rates were similar in both ecosystem types, once the decay started.

Conclusions

The faster start of decomposition in fallows seems to be promoted by higher contents of nitrates and phosphates in the fallow soils. The fallows, as younger ecosystems, may have faster C turnover than older grasslands due to remains of fertilisers on these ex-arable fields.
  相似文献   
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