全文获取类型
收费全文 | 142篇 |
免费 | 10篇 |
专业分类
林业 | 10篇 |
农学 | 2篇 |
基础科学 | 2篇 |
23篇 | |
综合类 | 24篇 |
农作物 | 3篇 |
水产渔业 | 10篇 |
畜牧兽医 | 69篇 |
园艺 | 1篇 |
植物保护 | 8篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 4篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 14篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 16篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有152条查询结果,搜索用时 15 毫秒
41.
Richter RA Freeman DE Wallig M Whittem T Baker GJ 《American journal of veterinary research》2002,63(7):934-941
OBJECTIVES: To study the functional and structural responses of the right dorsal colon (RDC) of ponies to phenylbutazone (PBZ) in vitro at a concentration that could be achieved in vivo. ANIMALS: 8 adult ponies. PROCEDURE: Short circuit current and conductance were measured in mucosa from the RDC. Tissues incubated with and without HCO3- were exposed to PBZ, bumetanide, or indomethacin. Bidirectional Cl- fluxes were determined. After a baseline flux period, prostaglandin E2 (PGE2) was added to the serosal surfaces and a second flux period followed. Light and transmission electron microscopy were performed. RESULTS: Baseline short circuit current was diminished significantly by PBZ and indomethacin, and increased significantly after addictions of PGE2. After PGE2 was added, Cl- secretion increased significantly in tissues in HCO3- -free solutions and solutions with anti-inflammatory drugs, compared with corresponding baseline measurements and with control tissues exposed to PGE2. Bumetanide did not affect baseline short circuit current and Cl- fluxes. The predominant histologic change was apoptosis of surface epithelial cells treated with PBZ and to a lesser extent in those treated with indomethacin. CONCLUSIONS AND CLINICAL RELEVANCE: Prostaglandin-induced Cl- secretion appeared to involve a transporter that might also secrete HCO3-. Both PBZ and indomethacin altered ion transport in RDC and caused apoptosis; PBZ can damage mucosa through a mechanism that could be important in vivo. The clinically harmful effect of PBZ on equine RDC in vivo could be mediated through its effects on Cl- and HCO3- secretion. 相似文献
42.
Effects of diet formulations containing proteins from different sources on intestinal colonization by Campylobacter jejuni in broiler chickens 下载免费PDF全文
Roy S. Udayamputhoor Harry Hariharan Ted A. Van Lunen P. Jeffrey Lewis Susan Heaney Lawrence Price David Woodward 《Canadian journal of veterinary research》2003,67(3):204-212
The objective of this study was to compare the effects of 3 diet formulations containing different protein sources (animal, plant, and a combination of animal and plant) on the colonization of Campylobacter jejuni in the gastrointestinal tract of broiler chickens. A freshly isolated strain of C. jejuni (biotype IV, serotype HS O:21, O:29, HL untypable) from a broiler chicken was used to infect 3-day-old chicks that had been free of C. jejuni; 0.5 mL of an inoculum containing 108 colony-forming units was administered orally. Shedding of the organism was studied, and C. jejuni in the ceca, jejuni, and crop were enumerated by quantitative culture. The isolates recovered from the birds during the study period of 35 d were characterized and confirmed as C. jejuni by the use of standard methods and underwent biotyping, serotyping, antimicrobial susceptibility testing by disk diffusion and the E-test, and flagellin gene typing. A cyclical pattern of shedding of C. jejuni was observed in all the birds. Colonization was highest in the ceca. The ceca of birds receiving plant-protein-based feed had significantly less colonization then the ceca of birds receiving the other types of feed, whereas the differences in colonization of the jejuni and crops were not significant. Characterization by biotyping, serotyping, and flagellin gene typing showed that 95% of the recovered isolates were identical to the strain used for infecting the chicks. However, with the Lior-HL typing scheme, 74% of the recovered isolates were HL untypable. Antimicrobial resistance testing did not reveal significant differences between the infecting strain and the recovered isolates among the different feed groups. 相似文献
43.
44.
Two-point ultrasound-guided transversus abdominis plane injection in canine cadavers – a pilot study
Emma K. Johnson Sébastien H. Bauquier Jennifer E. Carter Ted Whittem Thierry Beths 《Veterinary anaesthesia and analgesia》2018,45(6):871-875
Objective
This study evaluated the spread of a two-point transversus abdominis plane (TAP) injection in canine cadavers. Compared with previous techniques, the two-point TAP injection was developed to increase the consistency of local anaesthetic spread to the nerve segments T11, T12, L1, L2 and L3.Study design
Prospective experimental trial.Animals
Five fresh canine cadavers.Methods
Two-point TAP injections were performed under ultrasound guidance by a single trained individual in canine cadavers (15.7–43.0 kg). Each hemi-abdomen was infiltrated and evaluated independently for a total of 10 evaluations of the technique. The first injection was performed at the level of the costo-chondral junction of the thirteenth rib, and the second injection was performed cranial to the tuber coxae. Each injection comprised 0.3 mL kg–1 methylene blue solution (0.0015 mg mL–1). Ten minutes after the injections, abdominal wall dissection was performed, and any nerves stained for a minimum of 10 mm along their long axis were identified and recorded.Results
During all injections, separation of the internal oblique and transversus abdominis muscles was observed on ultrasound. On dissection, branches of T12, T13, L1, L2 and L3 were adequately stained in 30%, 100%, 100%, 90% and 90% of injections, respectively. No staining of branches of T11 occurred in any of the cadavers. In one hemi-abdomen, branches of L1 and L3, but not L2, were stained.Conclusions and clinical relevance
This study indicates that the two-point TAP injection delivers consistent dye dispersion to adequately stain branches of T13, L1, L2 and L3, with no coverage of T11 and poor coverage of T12, in fresh canine cadavers. An in vivo study using local anaesthetic should be performed to evaluate the analgesic efficacy of this technique in mid to caudal abdominal surgeries. 相似文献45.
Spatial distribution of soil nutrient at depth in black soil of Northeast China: a case study of soil available phosphorus and total phosphorus 总被引:2,自引:0,他引:2
Shaoliang Zhang Ted Huffman Xingyi Zhang Wei Liu Zhihua Liu 《Journal of Soils and Sediments》2014,14(11):1775-1789
Purpose
The spatial variability of soil available phosphorus (AP) and total phosphorus (TP) influences crop yield and the environment. The paper aims to identify the spatial heterogeneity of P (AP and TP) and clarify the main driving mechanisms in a Mollisol watershed of Northeast China.Materials and methods
Both geostatistical and traditional analysis were used to describe the spatial distribution of P at different depths. P in cultivated fields on the upper slopes was compared with secondary forest areas on the lower slopes within the same watershed.Results and discussion
The horizontal distribution of P was found to be primarily influenced by structural factors (58–95 %). TP was high at both the summit and the bottom of slopes at all depths, being especially high at the watershed outlet due to erosion on the back slope and deposition at the base. AP was higher on south-facing slopes than on north-facing slopes and typically decreased from the summit to the base of south-facing slopes at the 0–40-cm depths, mainly due to solar radiation, soil loss, and water loss. The vertical distribution of TP typically decreased with increasing depths in farmland but did not show systematic variation in the forest profiles. AP was lower in the middle of the 0–60-cm soil profiles in the farmland, reflecting the influence of fertilization, infiltration, and crop absorption. AP in the 30–60-cm and TP in the 20–60-cm layers were lower in farmland than in the secondary forest, and only 2 % of the area showed a risk of P loss through ground flow and infiltration in the 0–20-cm layer.Conclusions
The horizontal distribution of P in the 0–60-cm layers was mainly influenced by soil and water loss, deposition, and hydrothermal dynamics, while the vertical distribution of P, especially AP, was more affected by fertilization, infiltration, organic matter, and crop absorption. Secondary forestland that had been converted from farmland was found to effectively hold P, especially in deep soil layers, as the loss of P dissolved in water is not a primary process. 相似文献46.
Min B. Rayamajhi Paul D. Pratt Ted D. Center Thai K. Van 《European Journal of Forest Research》2010,129(6):1155-1168
The exotic tree Melaleuca quinquenervia (melaleuca) forms dense forests usually characterized by low plant diversities and dense litter biomass accumulations on
forest floors of ecologically sensitive ecosystems, including portions of the Florida Everglades. We quantified litter accumulation
in mature melaleuca stands and compared decomposition rates of melaleuca leaves with a sympatric native plant, either Cladium jamaicense (sawgrass) in sawgrass marshes or Pinus
elliottii (slash pine) in pine flatwoods habitats that varied in soil types. Total litter accumulation in mature melaleuca forests
prior to June 1997 ranged from 12.27 to 25.63 Mg ha−1. Overall, melaleuca leaves decomposed faster in organically rich versus arenaceous soils. Decomposition rates were lower
for melaleuca leaves than for sawgrass in both melaleuca-invaded and uninvaded sawgrass marshes. In arenaceous soils of pine
flatwoods, melaleuca leaf and pine needle decomposition rates were similar. Complete mineralization of sawgrass leaves occurred
after 258 weeks, whereas melaleuca leaves had up to 14% and pine foliage had up to 19% of the original biomass remaining after
322 weeks. Total carbon (C) in intact decomposing leaves varied slightly, but total nitrogen (N) steadily increased for all
three species; the greatest being a fourfold in sawgrass. Increases in N concentrations caused decreases in the C/N ratios
of all species but remained within an optimal range (20–30) in sawgrass resulting in higher decomposition rates compared to
melaleuca leaves and pine needles (C/N ratio >30). Slower decomposition of melaleuca leaves results in denser litter layers
that may negatively affect recruitment of other plant species and impede their establishment in invaded communities. 相似文献
47.
Robert F. Polomski Milton D. Taylor Douglas G. Bielenberg William C. Bridges Stephen J. Klaine Ted Whitwell 《Water, air, and soil pollution》2009,197(1-4):223-232
In the greenhouse and container nursery production industry there is potential for runoff of nitrogen (N) and phosphorus (P), which may contaminate surface and groundwater. Since the 1950s constructed wetlands (CWs), as a simple, low-technology method, have been shown to effectively treat agricultural, industrial, and municipal wastewater. We investigated the N and P attenuating potential of three floating hydrophytes planted in a laboratory-scale subsurface flow (SSF) CW system. Over an 8-week period plants were supplied with N and P (0.39 to 36.81 mg·L?1 N and 0.07 to 6.77 mg·L?1 P) that spanned the rates detected in nursery runoff between the discharge and inflow locations of a commercial nursery currently employing CWs. Whole plant dry weight was positively correlated with N and P supplied. Highest N recovery rates were exhibited by water hyacinth (Eichhornia crassipes [Mart.] Solms.) and water lettuce (Pistia stratiotes L.). P recovery rates were similar for water hyacinth, water lettuce, and dwarf redstemmed parrotfeather (Myriophyllum aquaticum [Vell.] Verdc.). These floating hydrophytes can be cultivated in a SSF CW to remediate runoff losses of N and P. The possibility exists for integrating them into a polycultural remediation system that includes emergent aquatic macrophytes for processing and polishing nursery/greenhouse wastewater. 相似文献
48.
Long-term separate and combined effects of environmental hypercapnia and hyperoxia in Atlantic salmon (Salmo salar L.) smolts 总被引:2,自引:1,他引:2
Camilla Diesen Hosfeld Annhild Engevik Ted Mollan Torleif Markussen Lunde Rune Waagb Anne Berit Olsen Olav Breck Sigurd Stefansson Sveinung Fivelstad 《Aquaculture (Amsterdam, Netherlands)》2008,280(1-4):146-153
Atlantic salmon (Salmo salar L.) parr (mean start weight 50 g) were reared in freshwater (FW) and exposed to three levels of oxygen saturation measured in effluent water; control group (93% O2, LO2), medium (111% O2, MO2) and high (123% O2, HO2). Further three groups were exposed to similar water oxygen levels in combination with elevated carbon dioxide levels (17–18 mg L– 1 CO2), named LO2–CO2, MO2–CO2 and HO2–CO2, respectively. The experiment was run in duplicate tanks for 42 days, and the fish were subsequently transferred to the same seawater (SW) regime for 45 days for an assessment of post-smolt growth. As a consequence of the CO2 addition, tank pH levels in the FW period were reduced from 6.7 to 5.9 for the hypercapnia groups compared to for the normcapnia groups. Water temperature in FW ranged between 6.4 and 9.0 °C. Citrate was added to the water to complex labile aluminium.In the CO2 groups observed ventilation frequencies were significantly increased compared to the control (p < 0.05). This difference declined towards the end of the FW period, suggesting acclimation to elevated CO2. The degree of oxygenation appeared to contribute to the acclimation as the lowest mean ventilation frequency on day 36 was found in the HO2–CO2 group and the highest in the LO2–CO2 group. Lower plasma chloride and sodium levels were observed in the CO2 groups relative to the respective oxygenation groups during the FW period, while plasma chloride and sodium levels were normalised to equal levels for all groups after 44 days in SW. No significant differences were found among treatments for blood concentrations of red blood cells, haemoglobin, potassium and glucose during the experiment.By termination of the FW period, the HO2 group had significantly higher body weight than all other groups (p < 0.05), with specific growth rate significantly higher than the CO2 groups (p < 0.05). Further, the condition factor was significantly lower in all the CO2 groups at the end of the FW period compared to the control and normcapnia groups (p < 0.05). Although variable among replicates, occurrence of nephrocalcinosis was 10 times higher in the hypercapnia groups than in the control and normcapnia groups. Mortality was negligible (< 2.0%) during the trial, and most of the mortality occurred following SW transfer. 相似文献
49.
50.