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61.
Adhesion of sperm to a glass surface can be manifested by the low percentage of motile spermatozoa and lower speed. This crucial factor could disprove the sperm quality prediction from computer-assisted sperm analysis (CASA) results. In our study, this was particularly observed when solution L was used. However, protein supplementation was effective in the reduction in sperm adhesion. We found that albumin increased the sperm motility at concentrations of 0.25 % in solution L and 0.5 % in solution P. Casein was effective in both solutions at 0.25 % concentration. However, in solution L, the motility was lower than that measured in solutions P and L with the supplementation of BSA at 0.25 and 0.5 %. BSA supplementation was especially beneficial in terms of higher speed values regardless of an activation solution. Casein used with solution P allows us to obtain similar results as in the samples activated with BSA supplementation. Casein supplementation to solution L did not increase CASA results to the level observed in the samples activated with BSA added to the solution L. Our data suggest that the selection of an activation solution is one of the most crucial steps in the experiments requiring CASA data. Depending on the composition, different protein supplements should be used to reduce adhesion of sperm to a glass surface. We recommend the use of BSA at the 0.5–1 % concentration because at this level we obtained the highest CASA parameters in both activation media.  相似文献   
62.
The present study examined the influence of extract obtained from the interior of cells of yeast, Saccharomyces cerevisiae (NuPro®), on the growth, proximate composition, nonspecific cellular and humoral defense mechanisms, and protection against furunculosis in pikeperch (Sander lucioperca). It was noted that eight weeks of supplementation with 40 g of NuPro® kg?1 feed (containing approximately 0.22 % exogenic nucleotides) enhanced pikeperch innate immunity. Increased serum lysozyme activity and total Ig levels (P < 0.05) were noted in the NuPro®-fed group, which indicated the activation of nonspecific humoral defense mechanisms. Brewer’s yeast extract also stimulated nonspecific cellular defense mechanisms as indicated by the increased metabolic activity of blood phagocytes and pronephric macrophages, and in the increased intracellular killing activity of phagocytes and proliferative responses of T and B lymphocytes (P < 0.05). Additionally, reduced mortality (15 %) after the in vivo challenge with pathogenic Aeromonas salmonicida suggested that NuPro® activated nonspecific protection against furunculosis in pikeperch. The experimental feed did not have a significant impact on the growth or proximate composition of the fish (P > 0.05).  相似文献   
63.
Economic pressures and labor shortage are forcing forest owners to minimize silvicultural costs and manage their forests more intensively to enhance wood production and profitability. The need to improve the cost-efficiency of tree planting is spurring its mechanization. The cost-competitiveness and time consumption of mechanized tree planting in Finland were compared to manual planting (MP) in spot mounds formed with a mounding blade and with a continuously advancing spot mounder. The results suggest that mechanized planting must increase its current productivity by 25% and 100% in order to compete with spot mounding or continuously advancing mounder followed by MP, respectively. However, in the hands of skilled operators in optimal conditions, machines can be cost-effective. On average, mechanized planting required 20% less time than MP and excavator-based spot mounding, whereas MP and continuously advancing spot mounder required 30% less time. Effective use of modern machines requires a careful evaluation of the worksite and skilled operators applying optimal operational models.  相似文献   
64.
65.
Population fluctuations of the European tarnished plant bug (Lygus rugulipennis Popp.) on nursery-grown Scots pine, Pinus sylvestris L. were monitored with sweep net samples over five growing seasons. The effects of cypermethrin, lindane and oxydemetonmethyl insecticide sprayings on the occurrence of Lygus adults and nymphs and prevalence of bud disorders of pine seedlings were studied. The number of Lygus bugs was highest in 1984, the first year of the study, and thereafter the annual levels of the bug declined, reaching a low in 1988. On 2- and 3-year-old Scots pine seedlings the numbers of overwintered L. rugulipennis adults and nymphs correlated positively with the occurrence of abnormal buds. Cypermethrin sprayings significantly reduced the numbers of Lygus nymphs in 1985 and 1987. In 1986 significantly fewer damaged seedlings and L. rugulipennis adults were found in pine transplants treated with cypermethrin.  相似文献   
66.
Effect of cholecalciferol-enriched hen feed on egg quality   总被引:1,自引:0,他引:1  
Eggs are one of the most important sources of vitamin D in the human diet, and their vitamin D content can be further increased by adding more vitamin D to hen feed. To investigate this issue more closely, we performed two feeding experiments. In both, zero egg samples were collected while the hens were fed regular feeds with a vitamin D content of 1720 or 4280 IU/kg. In experiment 1, egg samples were collected 2, 4, 7, 9, 11, 13, 16, 23, and 30 days after beginning the high-cholecalciferol (11 200 IU/kg) feeding period. In experiment 2, samples were collected 2, 4, 6, 8, 13, 28, 56, 84, 112, 140, and 168 days after beginning the high-cholecalciferol (12 000 IU/kg) diet. The egg samples were then assayed for their cholecalciferol content, and some samples, also for the presence of 25-hydroxycholecalciferol by an HPLC method. Further, the vitamin D-fortified eggs were compared with the controls by a sensory evaluation, by conducting fatty acid and functional analyses (emulsion capacity, gel forming capacity, foaming properties) and by measuring eggshell strength. Because vitamin D can be toxic in high doses, we also performed histopathological tests on the hens at the end of experiment 2. The top cholecalciferol contents in egg yolk (ca. 30 microg/100 g) were reached 8-13 days from starting the high-cholecalciferol diet. After 112 days feeding the cholecalciferol content gradually decreased to ca. 22 microg/100 g. When added to eggs as described above, vitamin D did not affect their sensory or functional properties or their fatty acid composition. Moreover, the cholecalciferol levels used in this study appeared not to affect eggshell strength or to be harmful for hens.  相似文献   
67.
The aim of this study was to examine the effect of common diterpenes (colophony, abietic acid) and triterpene (beta-sitosterol) on carbon (C) and nitrogen (N) transformations in soil under birch (Betula pendula L.). Samples were taken from the organic layer at two study sites, Kivalo (N-poor soil) and Kerimäki (N-rich soil), and incubated with the above-mentioned terpenes in laboratory conditions. Carbon dioxide evolution (C mineralization), net N mineralization, nitrification, and N and C in microbial biomass were measured. All these terpenes increased C mineralization, but decreased net N mineralization. The potential to decrease net N mineralization depended on amount of terpenes, with a stronger effect at a higher amount. Net nitrification in Kerimäki soil (N-rich soil) decreased but was not completely inhibited by terpenes. Effect of terpenes on soil microbial biomass C and N was not so clear, but they tended to increase both. Our study suggests that higher terpenes can act as a carbon source for soil microbial communities.  相似文献   
68.
Bacterial (meningococcal) meningitis is a devastating infectious disease with outbreaks occurring annually during the dry season in locations within the ??Meningitis Belt??, a region in sub-Saharan Africa stretching from Ethiopia to Senegal. Meningococcal meningitis occurs from December to May in the Sahel with large epidemics every 5?C10?years and attack rates of up to 1000 infections per 100,000 people. High temperatures coupled with low humidity may favor the conversion of carriage to disease as the meningococcal bacteria in the nose and throat are better able to cross the mucosal membranes into the blood stream. Similarly, respiratory diseases such as influenza and pneumonia might weaken the immune defenses and add to the mucosa damage. Although the transmission dynamics are poorly understood, outbreaks regularly end with the onset of the rainy season and may begin anew with the following dry season. In this paper, we employ a generalized additive modeling approach to assess the association between number of reported meningitis cases and a set of weather variables (relative humidity, rain, wind, sunshine, maximum and minimum temperature). The association is adjusted for air quality (dust, carbon monoxide), as well as varying degrees of unobserved time-varying confounding processes that co-vary with both the disease incidence and weather. We present the analysis of monthly reported meningitis counts in Navrongo, Ghana, from 1998?C2008.  相似文献   
69.
This study reports the evaluation of chemical composition of a Black Vistula and White Vistula streams’ waters taking into consideration both geological conditions of the stream’s catchment area and different water’ level related to seasonal variations in particular catchment ecosystem (high stage: beginning of the vegetation period; medium stage: vegetation period; low stage: final time of vegetation period). The complex data matrix (744 observations), obtained by the determination of major inorganic analytes (Cl?, NO3 ?, SO4 2?, NH4 +, Na+, K+, Ca2+, Mg2+) in water samples by ion chromatography was treated by linear discriminant analysis and non-parametrical testing. In case of both streams obtained results indicate presence of two discriminant functions (DFs). The data variance explained by DFs is as follows: Black Vistula stream—first DF: 93.5%, second DF: 6.5%; White Vistula stream—first DF: 66.3%, second DF: 33.7%. In case of Black Vistula stream first DF allows distinction of medium, high and low waterstage related samples while second DF between high/low and medium water stage related samples. In case of White Vistula stream first DF allowed to distinguish between medium/high and low water stage related samples while second DF between medium and high water level samples. In case of both streams, the most informative DFs were related to geological conditions of investigated catchments (contents of Cl?, Na+, K+, Mg2+, Ca2+, SO4 2?), while the second to nutrient biocycle (mainly NH4 + and NO3 ?) related to slope’s exposition and inclination.  相似文献   
70.
The influence of procyanidin extract from Japanese quince fruit on the activities of matrix metalloproteinases MMP-2 and MMP-9 secreted to culture medium by human peripheral blood mononuclear cells (PBMC) and by human leukemia HL-60 cells was investigated by gelatin zymography. The extract proved to be an effective inhibitor of the enzymes activities (for MMP-2 and MMP-9 secreted by PBMC IC50 = 16-19 microg extract/mL and 22-25 microg extract/mL, respectively). To identify the most effective components of the extract it was fractionated by means of column chromatography on TSKgel Toyopearl HW-40 (S) bed. The obtained fractions were analyzed by TLC, HPLC, and MALDI-TOF MS. Their antioxidant activity was measured as cation radicals ABTS(.+) scavenging efficiency. The fractions VIII-XIV containing oligomers from trimer to hexamer (and probably higher oligomers) appeared to be the most effective inhibitors of MMP-2 and MMP-9 activity (IC50 value close to 4.6 microg total polyphenols/mL). To the best of our knowledge, it is the first report on gelatinase-inhibitory activity of Japanese quince fruit polyphenol extract. We conclude that polyphenols from Japanese quince can be used in cancer chemoprevention, although further studies are needed to elucidate the mechanisms underlying their biological activities.  相似文献   
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