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421.
Molecular characterization of seedborne pathogens is an important issue when discerning their origin and tracking the spread of a disease. In the Canary Islands (Spain), Clavibacter michiganensis subsp. michiganensis (Cmm) was first detected in 2002, causing severe losses in many tomato-growing areas. Fifty four strains of this bacterium isolated from 2002 to 2007 and 19 strains from different countries were characterized for genetic diversity. RAPD-PCR, BOX-PCR and AFLP provided differentiation among Cmm strains whereas no differences were observed with ERIC-PCR, REP-PCR and 16S-23S ITS PCR-RFLP. RAPD-PCR and BOX-PCR revealed high homogeneity among the Canary Island strains (>80 and >75% of similarity, respectively) which could not be grouped based on tomato cultivar, location or year of isolation. By contrast, strains of Cmm from other countries displayed high diversity, providing several clusters, most of which were composed of a single strain. Similarly, AFLP analysis of 29 selected strains of Cmm gave the same profile for the Canarian ones (>90% of similarity) whereas high polymorphism was obtained with strains from different countries. Moreover, two strains, one from the USA and another from Spain, were related to the Canarian strains, according to RAPD-PCR (>60% of similarity), BOX-PCR (>75%) and AFLP analysis (>90%), suggesting a common origin. The circumstances under which the Cmm outbreaks occurred in the Canary Islands and the high homogeneity observed among the Canarian strains would suggest that the bacterium was introduced into the region from only one origin.  相似文献   
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423.

Objective

To evaluate the onset and duration of hematological changes and the use of Doppler ultrasound (spleen) in dogs sedated with acepromazine or xylazine.

Study design

Clinical study.

Animals

A total of 24 mixed breed dogs aged 1–4 years and weighing 15–25 kg.

Methods

Dogs were randomly distributed into two groups: acepromazine group (AG) which were administered acepromazine (0.05 mg kg?1) intramuscularly and xylazine group (XG) administered xylazine (0.5 mg kg?1) intramuscularly. Sonographic evaluations (morphologic and hemodynamic splenic vascularization) and hematologic tests were performed before drug administration (baseline) and 5, 15, 30, 60, 120, 240, 360, 480 and 720 minutes after drug administration.

Results

A significant reduction occurred in erythrogram variables in AG at 15–720 minutes corresponding with a significant enlargement of the spleen. In XG, a significant reduction was observed in the erythrogram variables at 30–60 minutes without a significant enlargement of the spleen. Hilar diameter did not change over time in either group. Flow alterations were found only in the splenic artery in AG, with a decreased final diastolic velocity observed at 60–120 minutes.

Conclusions

Administration of acepromazine resulted in decreased red blood cell count, hemoglobin, packed cell volume and an increased diameter of the spleen. Xylazine administration resulted in similar hematologic changes but of smaller magnitude and duration and without splenic changes. The absence of significant changes in the Doppler flow parameters of the splenic artery and vein and the hilar diameter suggests that the splenomegaly that was observed in AG was not due to splenic vasodilation. No splenic sequestration occurred after xylazine administration.

Clinical relevance

The results indicate that acepromazine decreases the erythrocyte concentrations by splenic erythrocyte sequestration and concomitant splenomegaly. Xylazine can cause slight hematologic changes, but without splenic changes.  相似文献   
424.
Spontaneous colonization of mine tailing dams by plants is a potential tool for phytostabilization of such reservoirs. However, the physical and chemical properties of each mine tailings deposit determine the success of natural plant establishment. The plant Baccharis linearis is the main native nanophanerophyte species (evergreen sclerophyllous shrub) that naturally colonizes abandoned copper tailings dams in arid to semiarid north-central Chile. This study compare growth of B. linearis against the physical and chemical properties of a Technosol derived from copper mine tailings. Five sites inside the deposit were selected based on B. linearis vegetation density (VD), at two soil sampling depths under the canopy of adult individuals. Physical and chemical properties of tailings samples and nutrient concentrations in tailings and plants were each determined. Some morphological features of the plants (roots and aerial parts) were also quantified. There were significant differences in soil available water capacity (AW) and relative density (Rd) at different VD. Sites with low AW and high Rd had lower nutrient concentrations and higher Zn content in tailings, decreased infection by arbuscular mycorrhizal fungi, and increased fine root abundance and root hair length in individual plants. In contrast, higher AW, which was positively correlated with fine particles and organic matter content, had a positive effect on vegetation coverage, increased N and P contents in tailings, and increased N contents in leaf tissues, even when available N and P levels in tailings were low. Multiple constraints, such as low AW, N, P, and B contents and high Zn concentrations in the tailings restricted vegetation coverage, but no phenotypic differences were observed between individuals. Thus, in order to promote dense coverage by B. linearis, water retention in these tailings must be improved by increasing colloidal particles (organic and/or inorganic) contents, which have a positive effect on colonization by this species.  相似文献   
425.
An individual-tree growth model was developed with data from 54 permanent plots of Scots pine (Pinus sylvestris L.) located in Galicia (northwestern Spain). The study involved two model fitting approaches, one considering constant growth and mortality rates in the period between two consecutive inventories, and another considering variable growth and mortality rates in the same period. The individual-tree growth model was based on annual basal area growth, height growth and survival probability. The model included variables from groups pertaining to tree size, competition and age. Weighted regression was used as a tool for dealing with missing height observations in model fitting. Evaluation of the model via simulation of growth and mortality in the period between inventories showed that the variable growth rate approach provided slightly better results than the constant growth rate approach. The final model was consistent with expected diameter growth, height growth, dominant height growth, stand basal area growth and reduction in number of stems per hectare.  相似文献   
426.
To possibly reduce postoperative adhesions that occur after ocular myoplasties, we investigated the topical effects of 0.04% mitomycin C on the repaired areas of the medial rectus muscle using an equine renal capsule preserved in 98% glycerin for reinforcement of the sutures. Twenty-four rabbits, divided into two groups of 12 animals each [untreated (control) and treated group (MMC)], were submitted to surgical rupture of the medial rectus muscle of one eye and repair of the defect 24 h later with sutures and an equine renal capsule. Post-operative prophylactic treatment of the two groups consisted of the administration of eye drops containing neomycin, polymyxin B and dexamethasone at regular 6-h intervals for eight consecutive days and daily rinsing with physiological saline. MMC animals received additional treatment with topical 0.04% mitomycin C every 6 h for 14 consecutive days. Slit lamp biomicroscopy showed greater irritation of the ocular surface in MMC animals during the first days post operatively. Adhesions were observed at 15 and 30 days of assessment in the two groups, but were more extensive in control animals at 60 days. Histopathology revealed inflammatory exudation in both groups, which was greater in MMC animals. Mitomycin C (0.04%) instilled at 6-h intervals for 14 consecutive days reduced the occurrence of fibrosis in the myoplastic areas. However, the equine renal capsule was found to be of little benefit for the reinforcement of myoplasties.  相似文献   
427.
428.
ABSTRACT

Information regarding carbon concentration and wood density are lacking in Chilimo dry Afromontane forest.

The aim of this study was to estimate carbon concentration and wood density for Allophyllus abyssinicus, Olea europaea, Olinia rochetiana, Rhus glutinosa, and Scolopia theifolia. A total of 105, 30–50 mm thick wood discs were collected and oven dried at 102°C and 67°C to constant weight, chopped and finally grinded into 0.2 mm with a grinding mill. Carbon concentration was analyzed using the ash method, while wood density was estimated using the water displacement method. The highest carbon concentration (57.12%) was found for O. rochetiana, however, the lowest carbon concentration (56.43%) was found for A. abyssinicus. Stem parts had higher carbon concentration (56.98%) than branch (56.74%) and leave (54.53%) parts. O. europaea exhibited the highest wood density (0.67 g cm?3) value than other species. However, the lowest wood density (0.42 g cm?3) was exhibited for A. abyssinicus. Wood density was also showed a decreasing trend along with increases in stem height and maximum wood density (0.62 g cm?3) was found under stump position, while, the minimum wood density (0.4 g cm?3) was found under tree commercial height.  相似文献   
429.
The aim of this work was to determine whether a cervical dilation protocol (CDP) composed of only oxytocin can be used to perform transcervical (non-surgical) embryo transfer in sheep (NSET) without affecting the viability of the corpus luteum (CL). Likewise, we evaluated whether a cervical transposing test with a Hegar dilator (CT Hegar test), performed at oestrous time, could be used to screen ewes for NSET (greater or lower chances to transpose the cervix). For that, oestrous and ovulation synchronization was performed in 25 Santa Inês ewes to induce the dioestrous condition. Animals went through the following CDP in a crossover design: E + OX, oestradiol benzoate (100 µg intravenously [IV]) and oxytocin (100 IU IV); OX, oxytocin (100 IU IV); and SAL, saline solution (IV). Using a Hegar dilator, cervical transposing attempts were performed at oestrous (D0) and dioestrous time (D8). The viability of the CL (morphology, luteal blood flow and progesterone values) was evaluated by ultrasonography (colour Doppler and B-mode) and by serum progesterone measurement from D7 to D13. The cervical transposing rate was lower for the SAL group (64%; 16/25; p < .05) and did not differ between the E + OX (88%; 22/25, p > .05) and OX (84%; 21/25, p > .05) groups. No treatment affected the CL viability. The CT Hegar test showed a high sensitivity (85.7%–93.3%), satisfactory accuracy (72%–84%), low false-negative rate (6.7%–14.6%), but high false-positive rate (46%–66.7%). In conclusion, a CDP protocol composed exclusively of oxytocin can lead to good cervical transposing rates and does not affect the viability of the CL. In addition, a screening test (CT Hegar) performed at oestrus can identify ewes for which cervical transposing will likely not occur at NSET.  相似文献   
430.
To evaluate the effects of crude protein (CP) and lactose (LAC) for weaned piglets on performance, intestinal morphology, and expression of genes related to intestinal integrity and immune system, 144 piglets with initial weight 7.17 ± 0.97 kg were allotted in a randomized design, in a 2 × 3 factorial arrangement (20.0% and 24.0% CP and 8.0%, 12.0%, and 16.0% LAC) with eight replicates. Piglets fed 20.0% CP had greater weight gain and feed intake. Including 12.0% LAC in the 20.0% CP diet provided higher villous height in the duodenum than 8.0% LAC, and 12.0% or 16.0% LAC in the 24.0% CP diet resulted in higher villous height in the jejunum and ileum, and higher villi/crypt ratio in the ileum than 8.0% LAC. No effects of CP and LAC on interleukin‐1β and tumor necrosis factor‐α mRNA were observed. The 16.0% LAC diet provided higher gene expression of transforming‐β1 growth factor. Feeding 20.0% CP resulted in better performance than 24.0% CP. The 12.0% LAC diet promoted greater genetic expression of occludin and zonula occludens. Including 12.0% LAC in the diet may improve intestinal epithelial morphology and integrity, and these improvements are more evident when piglets are fed diets with 24.0% CP.  相似文献   
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