全文获取类型
收费全文 | 324篇 |
免费 | 23篇 |
专业分类
林业 | 15篇 |
农学 | 15篇 |
基础科学 | 2篇 |
114篇 | |
综合类 | 12篇 |
农作物 | 24篇 |
水产渔业 | 41篇 |
畜牧兽医 | 90篇 |
园艺 | 4篇 |
植物保护 | 30篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 15篇 |
2020年 | 17篇 |
2019年 | 18篇 |
2018年 | 21篇 |
2017年 | 16篇 |
2016年 | 18篇 |
2015年 | 12篇 |
2014年 | 9篇 |
2013年 | 14篇 |
2012年 | 23篇 |
2011年 | 27篇 |
2010年 | 14篇 |
2009年 | 11篇 |
2008年 | 24篇 |
2007年 | 17篇 |
2006年 | 22篇 |
2005年 | 11篇 |
2004年 | 9篇 |
2003年 | 13篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有347条查询结果,搜索用时 15 毫秒
311.
Rodrigo B Nogueira DVM MS Michiko Sakate DVM MS PhD Beatriz B Matsubara MD MS PhD Renato de Souza Gonalves MD Guilherme J Magalhes Rosa BS MS PhD 《Journal of Veterinary Cardiology》2003,5(2):29-32
The objective of this study was to evaluate the electrocardiographic alterations in the cardiac rhythm in dogs treated with levamisole hydrochloride over a period of 24 hours. Thirty-six mixed-breed dogs, both male and female, all clinically healthy, were used in the experiment. The dogs were divided into 6 groups with 6 dogs in each group, according to dosage and route of administration. The Holter test was initiated immediately after the treatment, and was maintained for 24 hours. In the group treated with 10 mg/kg by way of subcutaneous injection, one of them showed ventricular premature complexes, sometimes isolated and other times in pairs, and ventricular tachycardia, concentrated mainly in the first hour after administration of the drug. In the group of 6 animals treated subcutaneously with 25mg/kg, four showed isolated ventricular premature complexes, ventricular bigeminy and trigeminy, mainly during the first 2 hours after administration of the drug. All the animals in the other groups showed sinus arrhythmia followed by sinus arrest. The disturbances in the cardiac rhythm observed in clinically healthy animals treated with levamisole hydrochloride, indicate that it is preferable to avoid subcutaneous administration of levamisole hydrochloride and that the oral administration of the drug should be done with caution. 相似文献
312.
A two‐and‐a‐half year‐old male Chinese hamster (Cricetulus griseus) was referred for evaluation of an intraorbital mass involving the right eye. Based on ophthalmic examination and ultrasonography, a diagnosis of intraocular neoplasia was made. Enucleation of the affected eye was performed. The mass was histologically diagnosed as a primary malignant intraocular signet‐ring cell melanoma. No signs of recurrence were detected, and the hamster remained clinically healthy until it died 6 months after surgery. This case report attempts to contribute to the limited body of knowledge available in the literature on primary intraocular neoplasms in hamsters. 相似文献
313.
Clarissa MR. Moreira Renato LS. Oliveira Gilberto A. Costa Katia B. Corgozinho Stelio PL. Luna Heloisa JM. Souza 《Veterinary anaesthesia and analgesia》2021,48(1):134-141
ObjectiveTo evaluate the analgesic efficacy and safety of tumescent local anesthesia (TLA) in cats undergoing unilateral mastectomy.Study designProspective clinical trial.AnimalsA total of 12 ovariohysterectomized female cats.MethodsAll animals were premedicated with pethidine (4 mg kg–1) intramuscularly (IM), followed by induction of anesthesia with propofol (5 mg kg–1) intravenously and maintenance with isoflurane in oxygen. A refrigerated TLA solution (15 mL kg–1, 8 °C) was injected using a Klein cannula. The solution was composed of 0.5 mL of epinephrine (1 mg mL–1) and 40 mL of 2% lidocaine added to 210 mL lactated Ringer’s solution (final lidocaine concentration 0.32%). Heart and respiratory rates, systolic arterial blood pressure, temperature and oxygen saturation were measured during anesthesia. Blood samples were collected from the jugular vein for measurement of plasma lidocaine concentration using high performance liquid chromatography. Postoperative pain scores were evaluated hourly for 6 hours. Analgesic rescue was performed with tramadol (2 mg kg–1) IM and meloxicam (0.15 mg kg–1) subcutaneously.ResultsPlasma lidocaine concentration peaked at 90 minutes after injection of TLA, but no concentration considered toxic for the species was measured. The median postoperative analgesia time was 6 hours after injection of TLA.ConclusionsThis study found that TLA prevented sympathetic response to noxious stimuli during anesthesia and provided satisfactory postoperative analgesia in cats submitted to total unilateral mastectomy, with no apparent signs of toxicity.Clinical relevanceTLA can prevent sympathetic stimulation resulting from noxious stimuli during anesthesia, promoting good intraoperative conditions, proving to be a viable addition to analgesia in cats submitted to a total unilateral mastectomy. 相似文献
314.
Renato Varges Bruno Penna Gabriel Martins Rodrigo Martins Walter Lilenbaum 《Veterinary ophthalmology》2009,12(4):216-220
Objective The purpose of this study was to describe the species distribution and antimicrobial susceptibility patterns of Staphylococci isolated from naturally occurring canine ocular diseases.
Samples and Procedures Samples obtained from 68 dogs with signs of external eye disease were processed for isolation of bacteria of the genus Staphylococcus sp. Isolates were identified by biochemical reactions and tested for susceptibility to 11 antimicrobials of six classes.
Results Forty (58.8%) samples yielded Staphylococcus sp. in pure culture. Coagulase-positive Staphylococci were most common and Staphylococcus intermedius was the most frequent (45%) species, followed by S . aureus (22.5%) and the coagulase-negative species S. epidermidis (20%), and S . simulans (12.5%). Resistance to at least one drug was observed in 92.5% of the isolates, and multidrug resistance was a common finding (72.5%). The most effective drugs against Staphylococcus strains isolated from extra-ocular canine ocular diseases were ceftiofur and cefalexin.
Conclusion This study highlights the presence of Staphylococcus sp. genus in naturally occurring extra-ocular canine ocular disease and the emergence of resistant strains to common antimicrobial drugs. It also emphasizes the need for bacterial culture with species identification and susceptibility testing in order to choose the appropriate antimicrobial therapy. 相似文献
Samples and Procedures Samples obtained from 68 dogs with signs of external eye disease were processed for isolation of bacteria of the genus Staphylococcus sp. Isolates were identified by biochemical reactions and tested for susceptibility to 11 antimicrobials of six classes.
Results Forty (58.8%) samples yielded Staphylococcus sp. in pure culture. Coagulase-positive Staphylococci were most common and Staphylococcus intermedius was the most frequent (45%) species, followed by S . aureus (22.5%) and the coagulase-negative species S. epidermidis (20%), and S . simulans (12.5%). Resistance to at least one drug was observed in 92.5% of the isolates, and multidrug resistance was a common finding (72.5%). The most effective drugs against Staphylococcus strains isolated from extra-ocular canine ocular diseases were ceftiofur and cefalexin.
Conclusion This study highlights the presence of Staphylococcus sp. genus in naturally occurring extra-ocular canine ocular disease and the emergence of resistant strains to common antimicrobial drugs. It also emphasizes the need for bacterial culture with species identification and susceptibility testing in order to choose the appropriate antimicrobial therapy. 相似文献
315.
Mauricio Almeida-Gomes Jayme Augusto Prevedello Renato Crouzeilles 《Landscape Ecology》2016,31(4):711-719
Context
Native vegetation is often used as a proxy for habitat to estimate habitat availability in landscapes. This approach may lead to incorrect estimates of the impacts of habitat loss and fragmentation on species, which have not been thoroughly quantified so far.Objectives
We quantified to what extent the loss of native vegetation reflect actual habitat loss by native species in landscapes. We tested the hypothesis that habitat availability declines at greater rates than native vegetation and thus is overestimated when it is quantified on the basis of native vegetation.Methods
Using simulations, we quantified how the loss of native vegetation in artificial and real landscapes affects habitat availability for species with different habitat requirements. We contrasted a generalist species, which uses all native vegetation, with 10 habitat-specialist species classified into three categories (interior, patchy and riparian species).Results
Habitat availability generally declined at greater rates than native vegetation for all specialist species. This pattern was apparent for different specialist species in a broad range of landscape types. Interior species always lost habitat availability more rapidly than the generalist species. Most riparian species lost habitat availability more rapidly than the generalist species. Responses of patchy species were more complex, depending on their dispersal abilities and landscape structure.Conclusions
Habitat availability is likely to be overestimated when native vegetation is used as proxy for habitat, because habitat availability will generally decline at greater rates than native vegetation. Therefore, a species-centered approach should be adopted when estimating habitat availability in landscapes.316.
Renato Crouzeilles Jayme Augusto Prevedello Marcos de Souza Lima Figueiredo Maria Lucia Lorini Carlos Eduardo Viveiros Grelle 《Landscape Ecology》2014,29(3):479-489
Habitat availability—or how much habitat species can reach at the landscape scale—depends primarily on the percentage of native cover. However, attributes of landscape configuration such as the number, size and isolation of habitat patches may have complementary effects on habitat availability, with implications for the management of landscapes. Here, we determined whether, and at which percentages of native cover, the number, size and isolation of patches contribute for habitat availability. We quantified habitat availability in 325 landscapes spread across the state of Rio de Janeiro, in the Atlantic Forest hotspot, with either high (>50 %), intermediate (50–30 %), low (30–10 %) or very low (<10 %) percentage of native cover, and for six hypothetical species differing in inter-patch dispersal ability. Above 50 % of native cover, the percentage of cover per se was the only determinant of habitat availability, but below 50 % the attributes of landscape configuration also contributed for habitat availability. The number of patches had a negative effect on habitat availability in landscapes with 50–10 % of native cover, whereas patch size had a positive effect in landscapes with <10 % of native cover. The different species generally responded to the same set of landscape attributes, although to different extents, potentially facilitating decision making for conservation. In landscapes with >50 % of native cover, conservation actions are probably sufficient to guarantee habitat availability, whereas in the remaining landscapes additional restoration efforts are needed, especially to reconnect and/or enlarge remaining habitat patches. 相似文献
317.
Agostina Chiavola Renato Baciocchi Federico Barducci 《Water, air, and soil pollution》2010,211(1-4):219-229
Mercury pollution in the Second Songhua River (SSR) was serious in the last century due to effluent from a chemical corporation. Effects of riverine self-purification on mercury removal were studied by comparing monitoring data of mercury concentrations varieties in water, sediment, and fish in the past, about 30 years. The present work suggested that a river of such a size like the SSR possessed the potential ability to recover from mercury pollution under the condition that mercury sources were cut off, though it needs a very long time, which might be several decades or even a century of years. During the 30 years with no effluent containing mercury input, total mercury (T-Hg) of water and sediment in some typical segments, mostly near the past effluent outlet, had decreased radically but still higher than the background values, though the decrease amplitudes were over 90% compared with that in 1975. T-Hg had decreased by more than 90% in most fishes, but some were still not suitable for consumption. Methylmercury concentrations (MeHg) of water, sediment, and fish were higher or close to the background levels in 2004. In the coming decades, the purification processes in the SSR would be steady and slow for a long period. 相似文献
318.
The marine environment is an important source of structurally-diverse and biologically-active secondary metabolites. During the last two decades, thousands of compounds were discovered in marine organisms, several of them having inspired the development of new classes of therapeutic agents. Marine mollusks constitute a successful phyla in the discovery of new marine natural products (MNPs). Over a 50-year period from 1963, 116 genera of mollusks contributed innumerous compounds, Aplysia being the most studied genus by MNP chemists. This genus includes 36 valid species and should be distinguished from all mollusks as it yielded numerous new natural products. Aplysia sea hares are herbivorous mollusks, which have been proven to be a rich source of secondary metabolites, mostly of dietary origin. The majority of secondary metabolites isolated from sea hares of the genus Aplysia are halogenated terpenes; however, these animals are also a source of compounds from other chemical classes, such as macrolides, sterols and alkaloids, often exhibiting cytotoxic, antibacterial, antifungal, antiviral and/or antifeedant activities. This review focuses on the diverse structural classes of secondary metabolites found in Aplysia spp., including several compounds with pronounced biological properties. 相似文献
319.
Pérez-Sirkin Daniela Irina Di Yorio María Paula Delgadin Tomás Horacio Honji Renato Massaaki Moreira Renata Guimarães Somoza Gustavo Manuel Vissio Paula Gabriela 《Fish physiology and biochemistry》2021,47(5):1527-1540
Fish Physiology and Biochemistry - Many teleost fishes can withstand long feed deprivation periods, either due to an eventual lack of food or because of their behavior during reproduction and/or... 相似文献
320.
Lucas Machado Figueira Nadja Gomes Alves Joanna Maria Gonçalves Souza-Fabjan Gabriel Brun Vergani Maria Emilia Franco Oliveira Renato Ribeiro de Lima Jeferson Ferreira Fonseca 《Reproduction in domestic animals》2020,55(11):1638-1645
This study assessed the cervical ultrasonography mapping as a tool to select donor ewes for non-surgical embryo recovery (NSER). Lacaune ewes had their cervix evaluated by ultrasonography 12 hr after induced oestrus onset (Trial 1, n = 24) or 30 min before NSER (Trial 2, n = 17). Cervical rings were longitudinally evaluated and classified by their degree of misalignment on ultrasonography (DMUS) into: DMUS-1—cervix rectilinear, DMUS-2—intermediate and DMUS-3—highly asymmetrical. For predicting cervical transposing, only DMUS-1 and DMUS-2 were considered suitable. Similar ranking was attributed to degree of misalignment on the cervical map (DMCM 1–3), established immediately before NSER, which was performed at days 6 to 7 after oestrus. In Trial 1, cervical retraction for NSER was not possible only in three ewes classified as DMUS-3 (3/14, 21.4%). No difference (p > .05) was observed in the cervical transposing rates between ewes with different DMUS (ranged from 80% to 100%). In Trial 2, DMUS-1 and DMUS-2 reached 100% of transposing, and the only DMUS-3 ewe has not been transposed. In Trial 1, the prediction performance for successful cervical transposing showed low sensitivity (45%) and no specificity due to a high incidence of false negatives (52%). However, in Trial 2, sensitivity and specificity were both 100%. The DMCM and DMUS were uncorrelated, probably due to cervical stretching required to perform NSER. In conclusion, cervical ultrasound assessment immediately before NSER was more efficient to predict the cervical transposing than at induced oestrus, allowing the classification and selection of ewes eligible for NSER. 相似文献