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61.
Marine sponges are an extremely rich and important source of natural products. Mariculture is one solution to the so-called "supply problem" that often hampers further studies and development of novel compounds from sponges. We report the extended culture (767 days) at sea in depths of 10 and 20 m of three sponge species: Negombata magnifica, Amphimedon chloros and Theonella swinhoei that produce latrunculin-B, halitoxin and swinholide-A, respectively. Since sponge-associated microorganisms may be the true producers of many of the natural products found in sponges and also be linked to the health of the sponges, we examined the stability of the bacterial communities in cultured versus wild sponges. Growth rate of the sponges (ranging from 308 to 61 and -19 (%)(year(-1)) in N. magnifica, A. chloros and T. swinhoei, respectively) differed significantly between species but not between the two depths at which the species were cultivated. Survivorship varied from 96% to 57%. During culture all species maintained the content of the desired natural product. Denaturing gradient gel electrophoresis analysis of the sponge-associated bacterial consortia revealed that differences existed between cultured and wild sponges in T. swinhoei and A. chloros but the communities remained quite stable in N. magnifica. The cultivation technique for production of natural products was found to be most appropriate for N. magnifica, while for T. swinhoei and A. chloros it was less successful, because of poorer growth and survival rates and shifts in their bacterial consortia.  相似文献   
62.
The Us3 gene is conserved among alphaherpesviruses and codes for a protein kinase, a multifunctional protein involved in many phases of virus infection, like nuclear egress, modulation of apoptosis and modification of the cellular cytoskeleton. Bovine herpesvirus (BHV-1), a member of the Alphaherpesvirinae, contains an open reading frame homologous to Us3 of other herpesviruses, which has been identified as a serine/threonine kinase (Takashima, Y., Tamura, H., Xuan, X., Otsuka, H., 1999. Identification of the Us3 gene product of BHV-1 as a protein kinase and characterization of BHV-1 mutants of the Us3 gene. Virus Res. 59, 23–34). To study the activity of BHV-1 Us3, we have cloned its sequence under control of the human cytomegalovirus (HCMV) promoter/enhancer and introduced it into a recombinant baculovirus (Bac Us3). Confocal microscopy analysis showed profound cytoskeletal modifications in various BHV-1-permissive and non-permissive cells transduced with BacUs3. We observed that Us3 expression changed cellular shape and induced formation of long microtubule-containing cell projections, a phenomenon which had also been observed in cells expressing pseudorabies virus Us3. The intracellular localization of Us3 was mostly nuclear but when the protein accumulated it could be detected in the cytoplasm, cell membranes and projections. Mutated forms of BHV-1 Us3 with point mutations near or within the kinase catalytic domain did not affect cell morphology indicating that kinase activity of BHV-1 Us3 is required for its cytoskeleton remodelling function.  相似文献   
63.
The aim of this study was to verify the usefulness of the measurement of chosen cardiovascular activity parameters for examination of sex pheromones effects in male dogs. We evaluated the influence of the bitches' sexual pheromones (BSP) on heart rate (HR) with the use of a Holter monitor, and chosen parameters of blood flow in vessels of penis, testes and kidney, with color-coded and pulsed Doppler ultrasonography. We found that the BSP increased HR in all examined males even without showing any other signs of arousal. There were no changes in the RI (resistant index) and PI (pulsative index) in any trials during the pheromone presentation. The increase in blood flow intensity was noted in penile vessels but not in the testes and kidney. We concluded that measurement of flow intensity in the penis as well as the changes in heart rate as the male's reaction to the BSP can be useful in research concerning sex pheromones in dogs.  相似文献   
64.
Within-field variability in wheat grain yield and its quality always exists in production fields and depends, among other factors, mainly on various soil properties related to nutrients and water availability. The aim of the research was to examine the relationships between selected soil properties such as texture; pH; content of the available phosphorus (P), potassium (K), magnesium (Mg), and organic carbon; and winter wheat grain yield and quality under rainfed conditions. Six crop fields with winter wheat (Triticum aestivum, L.) in three sites located in different regions of Poland were examined during two seasons. The grain yield was mainly determined by the soil texture, and the majority of the chemical soil properties did not have a significant effect on grain yield. The grain quality traits were determined by the examined soil properties to a smaller degree than grain yield. The relationships were not consistent across sites and years.  相似文献   
65.
The paper assess the variability of fat content and fatty acids profiles in seeds of a white lupin (Lupinus albus L.) domestic collection. The initial material comprised 371 accessions originated from 30 countries of Europe, Asia, Africa, North- and South America and Australia. According to data given by accession donors the material is divided into four classes of origin: wild lines, landraces, lines created by man and cultivars. Variability of fat content and fatty acids composition were estimated in seeds of each accession. The average fat content for analyzed collection is 9.81%. The broadest range of fat content was noticed for landraces and cultivars as compared to narrowest represented by lines created by man. Fat content ranged from 6.9% (induced mutant Wt 95497) to 14.1% (Polish cultivar Wt 95420 and the landrace Wt 95212 from Jordan). From a dietetic point of view, oil quality is more important than oil quantity in lupin seeds. On average the fatty acid (FA) in examined accessions ranked in following order of abundance: oleic acid (C18:1) > linoleic acid (C18:2) > linolenic acid (C18:3) > palmitic acid (C16:0) > eicosenoic acid (C20:1) > stearic acid (C18:0) ≈ erucic acid (C22:1). In respect to unsaturated fatty acid (UFA), monounsaturated oleic acid in each of estimated classes of accessions was predominant and most abundant (55.7%) in broad range of minimum–maximum values from 41.2 to 66.2%. The second examined monounsaturated fatty acid was erucic acid (1.74%) found in seeds of almost all studied accessions. An exception were four accessions defined similarly to rapeseeds as “zero erucic” forms. In seeds of few accessions a content of erucic acid exceeded 3%. Among polyunsaturated fatty acids linoleic FA (ω?6) dominated followed by linolenic FA (ω?3). Both FA were in the range 13.7–33.2% and 5.6–12.8% with mean values on the level 19.6 and 10.1%, respectively. As a consequence, the examined white lupin seeds showed a very favourable ω?3/ω?6 FA ratio (0.51), ranging from 0.21 to 0.87, much higher than that of most vegetable oils. Fat content was positively correlated with stearic and oleic fatty acids and negatively with palmitic, linoleic, linolenic and erucic acid.  相似文献   
66.
The main objectives of our study were to evaluate soil contamination on a zinc-lead spoil heap in the Upper Silesian Industrial Region in southern Poland using pollution indices, and to investigate the relation between soil properties and the natural succession of vegetation. Organic carbon and nitrogen, pH, soil texture, base cations, and heavy metal content were analyzed in soil samples at depths of 0–15 cm below the organic horizon over a regular grid of 14 sampling plots. The contents of Zn, Pb, and Cd exceeded by several times the acceptable thresholds. Measurements of soil enzyme activity were used to evaluate the progress of vegetation development in relation to soil chemical properties. The results indicate that heavy metals had a significant impact on soil enzyme activity and the development of vegetation cover. High contents of Pb and Cd reduced enzyme activity, while this activity increased with increasing amounts of soil organic matter. Further, the accumulative capacities of heavy metals in needles of Scots pine (Pinus sylvestris L.) and aboveground biomass of bladder campion (Silene vulgaris (Moench) Garcke) were examined. A high accumulation of Zn, Pb, and Cd in the aboveground tissues of S. vulgaris indicated an unusual tolerance of this species to heavy metals and the possibility of using this species in phytoremediation of post-industrial sites.  相似文献   
67.
Surgical skills are learned through deliberate practice, and veterinary educators are increasingly turning to models for teaching and assessing surgical skills. This review article sought to compile and review the literature specific to veterinary surgical skills models, and to discuss the themes of fidelity, educational outcomes, and validity evidence. Several literature searches using broad terms such as “veterinary surgery model,” “veterinary surgical model,” and “veterinary surgical simulator” were performed using PubMed, CAB abstracts, and Google scholar. All articles describing a model created and utilized for veterinary surgical training were included. Other review articles were used as a source for additional models. Commercially available models were found using review articles, internet browser searches, and communication with veterinary clinical skills educators. There has been an explosion of growth in the variety of small animal surgical task trainers published in the last several decades. These models teach orthopedic surgery, ligation and suturing, open celiotomy and abdominal surgery, sterilization surgeries, and minimally invasive surgeries. Some models were published with accompanying rubrics for learner assessment; these rubrics have been noted where present. Research in veterinary surgical models is expanding and becoming an area of focus for academic institutions. However, there is room for growth in the collection of validity evidence and in development of models for teaching large animal surgery, training surgical residents, and providing continuing education to practitioners. This review can assist with evaluation of current surgical models and trends, and provide a platform for additional studies and development of best practices.  相似文献   
68.
Using historical growth series data of Scots pine (Pinus sylvestris L.) in Central Europe we examine all the dynamic site equations previously used for modeling the height growth of this species as well as a new dynamic site equation that has not been used previously in the context of this forestry data. The tested models included two groups of anamorphic and polymorphic dynamic site equations (three-dimensional site–height–age models, such as Y = f(t,t0,y0)). One group of the models is based on the algebraic difference approach (ADA) implementation of different, preexisting base equations (two-dimensional equations, such as Y = f(t)). The other group of models is based on newer generalized algebraic difference approach (GADA) formulations of new site–height–age relationships that may use older models only as a part of their structure. The models were selected because they were relevant to Scots pine height growth modeling in other studies. We compared all the models with each other in terms of the sum of square deviations associated with fitting them simultaneously to all sites represented by the Scots pine data. All the fits were based on base-age invariant stochastic regressions, in which the global model parameters that are common to all growth series are estimated simultaneously with the site-specific effects that are different for each of the site productivity series. Cieszewski's model [Cieszewski, C.J., 2005. A new flexible GADA based dynamic site equation with polymorphism and variable asymptotes. PMRC Technical Report 2005-2] best described the data.  相似文献   
69.
Mast seeding causes strong fluctuations in populations of forest animals. Thus, this phenomenon can be used as a natural experiment to examine how variation in host abundance affects parasite loads. We investigated fleas infesting yellow-necked mice in beech forest after 2 mast and 2 non-mast years. We tested 2 mutually exclusive scenarios: (1) as predicted by classical models of density-dependent transmission, an increase in host density will cause an increase in ectoparasite abundance (defined as the number of parasites per host), versus (2) an increase in host density will cause a decline in flea abundance (“dilution,” which is thought to occur when parasite population growth is slower than that of the host). In addition, we assessed whether masting alters the relationship between host traits (sex and body mass) and flea abundance. We found a hump-shaped relationship between host and flea abundance. Thus, the most basic predictions are too simple to describe ectoparasite dynamics in this system. In addition, masting modified seasonal dynamics of flea abundance, but did not affect the relationship between host traits and flea abundance (individuals with the highest body mass hosted the most fleas; after controlling for body mass, parasite abundance did not vary between sexes). Our results demonstrate that pulses of tree reproduction can indirectly, through changes in host densities, drive patterns of ectoparasite infestation.  相似文献   
70.

Background

Chronic mitral valve disease is frequently seen in the Dachshund. Dachshunds (n=207) made up 11.73% of the dogs admitted to the Cardiology Service at the Small Animal Clinic, Warsaw University of Life Sciences, Poland (first visits only).

Results

Of these, 35 dogs had no clinically detectable heart disease while 172 had chronic valve disease with the mitral valve affected most often (130 dogs), both mitral and tricuspid valves infrequently (39 dogs) and rarely the tricuspid valve (3 dogs). Males were affected more frequently than females and the average age of dogs with chronic valve disease was 11.9 years for females and 11.3 years for males. A majority of the diseased Dachshunds were classified as ISACHC 2 (79), followed by ISACHC 1 (60). Most frequent clinical signs noted by owners included coughing, exercise intolerance, dyspnea and tachypnea. Heart murmurs were generally louder with increased disease severity; however there were 20 dogs in the ISACHC 1 group with no audible heart murmurs. The most frequent electrocardiographic abnormalities included an increased P wave and QRS complex duration, increased R wave amplitude and tachycardia. With increased disease severity, echocardiography revealed an increase in heart size. A higher ISACHC class was related to increased heart size (based on echocardiography) and increased percentage of patients exhibiting enlargement of both left atrium and left ventricle (based on radiography).

Conclusions

The Dachshund is often affected by chronic mitral valvular disease with a late onset of associated clinical signs and few cardiac complications.  相似文献   
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