全文获取类型
收费全文 | 582篇 |
免费 | 44篇 |
专业分类
林业 | 44篇 |
农学 | 12篇 |
基础科学 | 3篇 |
97篇 | |
综合类 | 27篇 |
农作物 | 23篇 |
水产渔业 | 24篇 |
畜牧兽医 | 318篇 |
园艺 | 15篇 |
植物保护 | 63篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 15篇 |
2019年 | 14篇 |
2018年 | 12篇 |
2017年 | 17篇 |
2016年 | 22篇 |
2015年 | 23篇 |
2014年 | 31篇 |
2013年 | 29篇 |
2012年 | 49篇 |
2011年 | 59篇 |
2010年 | 32篇 |
2009年 | 51篇 |
2008年 | 49篇 |
2007年 | 41篇 |
2006年 | 31篇 |
2005年 | 30篇 |
2004年 | 31篇 |
2003年 | 20篇 |
2002年 | 16篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 5篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1978年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有626条查询结果,搜索用时 187 毫秒
21.
M. Campos R. Ducatelle H.S. Kooistra G. Rutteman L. Duchateau I. Polis S. Daminet 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(2):564-570
Background
Thyroid carcinoma is a common endocrine tumor in the dog. Local invasive growth frequently precludes surgical excision and, in up to 38% of dogs, the tumor has already metastasized by the time of diagnosis. Therefore, it is important to investigate new treatment modalities that may be useful for the large number of dogs with inoperable tumors or metastatic disease.Hypothesis/Objectives
To investigate the immunohistochemical expression of potential therapeutic targets in canine thyroid tumors.Animals
74 dogs with thyroid neoplasia.Methods
Immunohistochemistry was performed for thyroglobulin, calcitonin, vascular endothelial growth factor (VEGF), p53, cycloxygenase‐2 (cox‐2), and P‐glycoprotein (P‐gp).Results
Fifty‐four (73%) tumors were classified as follicular cell thyroid carcinomas (FTCs) and 20 (27%) as medullary thyroid carcinomas (MTCs). Eighty percent of FTCs and all MTCs had a high percentage (76–100%) of neoplastic cells immunopositive for VEGF. Thirteen percent of FTCs and 50% of MTCs expressed cox‐2. Seven percent of FTCs and 70% of MTCs expressed P‐gp. No tumor was immunopositive for p53 expression. Expression of VEGF (P = .034), cox‐2 (P = .013), and P‐gp (P < .001) was significantly higher in MTCs compared to FTCs.Conclusions and Clinical Importance
VEGF is a potential therapeutic target in both FTC and MTC in dogs. Cox‐2 and P‐gp may be useful molecular targets in canine MTC. 相似文献22.
Nathalie Porters Tim Bosmans Mariëlla Debille Hilde de Rooster Luc Duchateau Ingeborgh Polis 《Veterinary anaesthesia and analgesia》2014,41(1):90-96
ObjectiveTo compare sedation and antinociception after oral transmucosal (OTM) and intramuscular (IM) administration of a dexmedetomidine-buprenorphine combination in healthy adult cats.Study designRandomized, ‘blinded’ crossover study, with 1 month washout between treatments.AnimalsSix healthy neutered female cats, weighing 5.3–7.5 kg.MethodsA combination of dexmedetomidine (40 μg kg?1) and buprenorphine (20 μg kg?1) was administered by either the OTM (buccal cavity) or IM (quadriceps muscle) route. Sedation was measured using a numerical rating scale, at baseline and at various time points until 6 hours after treatment. At the same time points, analgesia was scored using a dynamic and interactive visual analogue scale, based on the response to an ear pinch, and by the cat’s response to a mechanical stimulus exerted by a pressure rate onset device. Physiological and adverse effects were recorded, and oral pH measured. Signed rank tests were performed, with significance set at p < 0.05. Data are presented as median and range.ResultsThere were no differences in sedation or antinociception scores between OTM and IM dosing at any of the time points. Nociceptive thresholds increased after both treatments but without significant difference between groups. Buccal pH remained between 8 and 8.5. Salivation was noted after OTM administration (n = 2) and vomiting after both OTM (n = 4), and IM (n = 3) dosing.Conclusions and clinical relevanceIn healthy adult cats, OTM administration of dexmedetomidine and buprenorphine resulted in comparable levels of sedation and antinociception to IM dosing. The OTM administration may offer an alternative route to administer this sedative-analgesic combination in cats. 相似文献
23.
Use of decision support systems (DSS) has thus far been framed as a social process of adoption or technical process of usability. We analyze the development of a DSS as a process of institutionalization of new as well as drift of existing practices. We write an Actor-Network-Theory (ANT) account, i.e. an interpretive study, that follows the traces left by both human and non-human actors (e.g. technology, methodologies, etc.) to understand how a DSS development project institutionalizes DSS technology in several forest management organizations in the German state of Rheinland Pfalz. The research has an innovative value since it uses ANT in the design of a DSS, hence affecting it, while commonly ANT has been used to understand why networks work or do not. Moreover, we use a new technology (PREZITM, www.prezi.com) for the visualization of the whole actor network coherent to the ANT methodology, i.e. “keeping the social flat.” As a result, the development of the ANT account proposed in the present paper, even if still partial, supports the design of new technologies being introduced in current practice and generates an important learning effect thanks to the underpinning interpretative approach. 相似文献
24.
Diane Saint-Laurent Julien St-Laurent Patricia Duplessis Luc Lavoie 《Water, air, and soil pollution》2010,209(1-4):451-466
Current and past industrial pollution leaves many traces in the environment, in particular along rivers in industrial and urban areas. The isotopic analysis of the lead found in soils and tree rings offers a kind of environmental archive for presenting a portrait of the pollutant distribution in the environment in both spatial and temporal terms. This study is an attempt to identify and compare the source of contamination found in soils and tree rings located along two rivers affected by pollution over several years. Specifically, the focus is on the pattern of lead concentrations and lead isotopic signatures (206Pb/207Pb, 208Pb/206Pb, and 206Pb/204Pb) detected in soils and tree rings located on polluted floodplains. The concentration of Pb in overbank sediments does not rise with the increasing distance downstream from the point source (mining area), suggesting that significant fluvial transport of the pollutant particles over 80 km is involved. For the soil profiles, Pb concentration levels range between 12.32 and 149.13 mg/kg, with the highest concentrations found at the base of the profiles (>1 m). For the lead isotope ratios in the soil profiles, the values obtained range from 0.851 to 0.872 (206Pb/207Pb), 2.081 to 2.111 (208Pb/206Pb), and 0.547 to 0.562 (206Pb/204Pb). The tree ring analysis of red ash (Fraxinus pennsylvanica Marsh.) shows average lead concentrations of 0.63 μg/g, and the lead values of all the tree specimens range between 0.03 and 11.38 μg/g. Pb concentrations varied greatly between the specimens in selected sites and lead isotope ratios in the tree rings showed a strong variability in the time series, particularly from 1945 to 1970. The greater number of variations in the lead concentration rates and isotopic ratios suggest that many more events associated with pollution and contamination have in fact occurred in this area. The study demonstrates the utility of combining stable isotope analyses (soils and tree rings) to examine the source and dispersion of contaminant Pb in fluvial systems by providing reliable and robust indicators for the detection of environmental changes on a local and regional scale. 相似文献
25.
26.
27.
de Bruin T de Rooster H Bosmans T Duchateau L van Bree H Gielen I 《The Veterinary record》2007,161(22):745-750
The formation and progression of osteoarthrosis in the unaffected contralateral stifle joints of 14 dogs with a unilateral cranial cruciate ligament rupture were monitored radiographically in terms of a global score and the scores for 10 parameters specific for the stifle joint. The dogs were examined initially and six and 12 months later by three observers, and the variability between the observers' scores was also assessed. The score for osteophytes at the tibial attachment site of the ligament was the most reliable parameter, and that for the increase in femoropatellar joint space was the least reliable. In the contralateral stifle joints there were significant increases after six and 12 months in osteophyte formation caudal to the tibial plateau, and in subchondral sclerosis of the tibial plateau and of the long digital extensor muscle groove. These three parameters progressed more regularly during the disease process than the other parameters. The global osteoarthrosis score of the contralateral stifle joint was an important risk factor for sustaining a rupture of the cranial cruciate ligament in that joint during the next six months. 相似文献
28.
Bonnefont-Rebeix C Marchal T Bernaud J Pin JJ Leroux C Lebecque S Chabanne L Rigal D 《Veterinary immunology and immunopathology》2007,118(1-2):134-139
Toll-like receptors (TLRs) are a family of functionally important receptors for recognition of pathogen-associated molecular pattern (PAMP) since they trigger the pro-inflammatory response and upregulation of costimulatory molecules, linking the rapid innate response to adaptative immunity. In human leukocytes, TLR3 has been found to be specifically expressed in dendritic cells (DC). This study examined the expression of TLR3 in canine monocytes-derived DC (cMo-DC) and PBMC using three new anti-TLR3 mAbs (619F7, 722E2 and 713E4 clones). The non-adherent cMo-DC generated after culture in canine IL-4 plus canine GM-CSF were labelled with the three anti-TLR3 clones by flow cytometry, with a strong expression shown for 619F7 and 722E2 clones. By contrast, TLR3 expression was low to moderate in canine monocytes and lymphocytes. These results were confirmed by Western blot using 619F7 and 722E2 clones and several polypeptide bands were observed, suggesting a possible cleavage of TLR3 molecule or different glycosylation states. In addition, TLR3 was detectable in immunocytochemistry by using 722E2 clone. In conclusion, this first approach to study canine TLR3 protein expression shows that three anti-TLR3 clones detect canine TLR3 and can be used to better characterize canine DC and the immune system of dogs. 相似文献
29.
Taylor JL Demyttenaere JC Abbaspour Tehrani K Olave CA Regniers L Verschaeve L Maes A Elgorashi EE van Staden J de Kimpe N 《Journal of agricultural and food chemistry》2004,52(2):318-323
Genotoxic compounds can act at various levels in the cell (causing gene, chromosome, or genome mutations), necessitating the use of a range of genotoxicity assays designed to detect these different types of mutations. The production of melanoidins during the processing and cooking of foods is associated with changes in their nutritional character, and the discovery of mutagenic substances in pyrolyzed protein and amino acids has raised concern about the safety of these foods. The aim of this work was to test melanoidin fractions in three different in vitro assays (Ames test, Vitotox test, and micronucleus test). These melanoidin fractions were produced from the condensation of glucose with glycine and their separation was conducted by dialysis. The crude reaction mixture (before dialysis) and both the LMW and HMW fractions obtained by dialysis showed no genotoxicity in these assays, despite being tested at concentrations much higher than those naturally found in food products. The LMW fraction, however, showed toxicity at these high concentrations. The volatile fraction produced in this reaction showed genotoxicity only in the Vitotox test, at high concentrations. 相似文献
30.
Sánchez-Moreno C Plaza L De Ancos B Cano MP 《Journal of agricultural and food chemistry》2003,51(3):647-653
Vitamin C, provitamin A carotenoids, and other carotenoids were measured in freshly squeezed juices from oranges (Citrus sinensis L. var. Valencia late) that were subjected to high-pressure (HP) treatment. Also, the stability of these compounds was studied during refrigerated storage at 4 degrees C. HP treatment is an alternative to heat preservation methods for foods; therefore, it is essential to assess the impact of HP on bioactive compounds. Several processes that combine HP treatment with heat treatment for various time periods were assayed: T0, fresh juice (without treatment); T1, 100 MPa/60 degrees C/5 min; T2, 350 MPa/30 degrees C/2.5 min; T3, 400 MPa/40 degrees C/1 min. Fresh and treated samples were kept refrigerated (4 degrees C) over 10 days. After application of HP and during the refrigeration period, the qualitative and quantitative determination of vitamin C, provitamin A carotenoids (beta- and alpha-carotene; beta- and alpha-cryptoxanthin), and the xanthophylls zeaxanthin and lutein was achieved by high-performance liquid chromatography. T1 and T3 juices showed a decrease in ascorbic acid and total vitamin C just after HP treatment (D0) compared with T0 juices. On the contrary, T2 juices, just after HP treatment (D0), had the same levels of both compounds compared to untreated juices. T1, T2, and T3 treatments led to an increase in the extraction of carotenoids and provitamin A carotenoids. Total carotenoid content after the 10-day refrigerated storage period resulted in no significant quantitative changes in T1 juices, whereas in T2 and T3 juices small losses were found at the end of the storage period (20.56 and 9.16%, respectively). These losses could be influenced by the depleted protection of vitamin C toward carotenoid oxidation during the same period. A similar trend was found in provitamin A carotenoids for the different treated juices. 相似文献