全文获取类型
收费全文 | 501篇 |
免费 | 55篇 |
专业分类
林业 | 13篇 |
农学 | 14篇 |
基础科学 | 8篇 |
76篇 | |
综合类 | 55篇 |
农作物 | 29篇 |
水产渔业 | 52篇 |
畜牧兽医 | 268篇 |
园艺 | 11篇 |
植物保护 | 30篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 14篇 |
2020年 | 9篇 |
2019年 | 31篇 |
2018年 | 20篇 |
2017年 | 23篇 |
2016年 | 19篇 |
2015年 | 17篇 |
2014年 | 21篇 |
2013年 | 34篇 |
2012年 | 27篇 |
2011年 | 38篇 |
2010年 | 23篇 |
2009年 | 20篇 |
2008年 | 11篇 |
2007年 | 24篇 |
2006年 | 21篇 |
2005年 | 14篇 |
2004年 | 17篇 |
2003年 | 18篇 |
2002年 | 17篇 |
2001年 | 16篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 13篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1969年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有556条查询结果,搜索用时 656 毫秒
81.
AEF Silva P Rodriguez LF Cavalcante BA Rodrigues JL Rodrigues 《Reproduction in domestic animals》2009,44(S2):259-262
High in vitro oxygen (O2 ) tensions are associated with enhanced levels of reactive oxygen species and cumulus oocyte complex (COC) apoptosis. The objective of this study was to determine the influence of O2 tension on cumulus cell (CC) viability from canine oocytes. Cumulus oocyte complexes were distributed into three groups (CG, T20 and T5) and two O2 tension levels (20% and 5%). The control group (CG) was matured in vitro in a humidified atmosphere with 5% CO2 in air in TCM199 with 26.19 m m sodium bicarbonate, 10% (v/v) foetal calf serum (FCS), 0.10 m m gentamicin, 0.20 m m pyruvic acid, 20 μg/ml oestradiol, 0.5 μg/ml follicle-stimulating hormone, 0.03 IU/ml human chorionic gonadotropin, and 1.0 μg/ml human somatotropin. Groups T20 and T5 were matured under 20% or 5% O2 tensions respectively in a high-glucose medium, without FCS. T20 and T5 were as CG, and supplemented with 0.1% Polyvinyl Alcohol, and 5.5 m m glucose. After 48 h of IVM, CCs from COCs were stained with propidium iodide (1.50 m m ). The results showed that viability of CCs (cytoplasmic features and nuclear morphological integrity) was different for the three groups. Rates of apoptosis were at 57.9% (521/900) for CG, 54.4% (490/900) for T20 and 38.9% (350/900) for T5 (p < 0.001). Predominant features in apoptotic cells (n = 1361) were DNA nuclear fragments (94.0%). It was concluded that CCs of canine COCs cultured in high-glucose medium showed significantly less apoptosis than those cultured in medium with FCS. Low O2 tension was efficient in reducing apoptosis in canine CCs. 相似文献
82.
A. Pellegrini‐Masini I. Rodriguez Hurtado A. J. Stewart T. J. Divers 《Equine Veterinary Education》2009,21(2):79-84
Venous air embolism was suspected in 3 hospitalised horses on the basis of an inadvertently open jugular venous line. Subsequently the 3 horses developed clinical signs including cardiovascular collapse, cardiac dysrhythmia, pulmonary oedema, behavioural abnormalities and neurological signs consistent with central nervous system injury. Treatment included intranasal oxygen therapy, i.v. fluid administration and anti‐inflammatory therapy. Specific therapy aimed at treating air embolism in man is reviewed, with pertinent therapy potentially applicable to horses emphasised. 相似文献
83.
Goiz-Marquez G Caballero S Solis H Rodriguez C Sumano H 《Research in veterinary science》2009,86(1):152-161
The purpose of this study was to evaluate both, clinically and with electroencephalographic (EEG) recordings, the effect of gold wire implants in acupuncture points in dogs with uncontrolled idiopathic epileptic seizures. Fifteen dogs with such diagnosis were enrolled in the study. A first EEG recording was performed in all dogs under anaesthesia with xylazine (1 mg/kg) and propofol (6 mg/kg) before the treatment protocol, and a second EEG was performed 15 weeks later. Relative frequency power, intrahemispheric coherence available through EEG, number of seizures and seizure severity were compared before and after treatment using a Wilcoxon signed-rank test. There were no significant statistical differences before and after treatment in relative power or in intrahemispheric coherence in the EEG recording. However, there was a significant mean difference in seizure frequency and seizure severity between control and treatment periods. After treatment, nine of the 15 dogs (60%) had at least a 50% reduction in seizures frequency during the 15 weeks established as follow-up of this treatment. 相似文献
84.
Detection of foot-and-mouth disease virus infected cattle using infrared thermography 总被引:1,自引:0,他引:1
Rainwater-Lovett K Pacheco JM Packer C Rodriguez LL 《Veterinary journal (London, England : 1997)》2009,180(3):317-324
In this study, infrared thermography (IRT) was assessed as a means of detecting foot-and-mouth disease virus (FMDV)-infected cattle before and after the development of clinical signs. Preliminary IRT imaging demonstrated that foot temperatures increased in FMDV-infected animals. The maximum foot temperatures of healthy (n = 53), directly inoculated (DI) (n = 12), contact (CT) (n = 6), and vaccine trial (VT) (n = 21) cattle were measured over the course of FMD infection. A cut-off value was established at 34.4 °C (sensitivity = 61.1%, specificity = 87.7%) with the aim of detecting FMDV-infected animals both before and after clinical signs were observed. Seven of 12 (58%) DI and 3/6 (50%) CT animals showed maximum foot temperatures exceeding the 34.4 °C cut-off before the development of foot vesicles. In contrast, only 5/21 (24%) VT animals displayed pre-clinical foot temperatures above this cut-off possibly indicating partial vaccine protection of this group. These results show IRT as a promising screening technology to quickly identify potentially infected animals for confirmatory diagnostic testing during FMD outbreaks. Further evaluation of this technology is needed to determine the value of IRT in detecting animals with mild clinical signs or sub-clinical infections. 相似文献
85.
J. Obidiegwu J. Loureiro E. Ene-Obong E. Rodriguez M. Kolesnikova-Allen C. Santos C. Muoneke R. Asiedu 《Euphytica》2009,169(3):319-326
The Guinea yams, Dioscorea
cayenensis Lam. and D. rotundata Poir. (D. cayenensis–D. rotundata complex), represent a highly important crop, widely distributed in the humid and semi-humid tropics. The ploidy levels of
170 accessions of the core set of Guinea yams from West African countries was determined using flow cytometry with propidium
iodide staining. One hundred and eight of the genotypes were found to be tetraploid, 47 were hexaploid and five were octoploid.
One mixoploid individual containing tetraploid and hexaploid nuclei was also detected. A deeper analysis considering each
separate taxon revealed that while for D. rotundata the majority of individuals were tetraploid, for D. cayenensis this ploidy level was not detected in any of the accessions. Also, no association between ploidy level and place of cultivation
was found for the evaluated germplasm. The obtained data is highly valuable for breeding programs of Guinea yam, especially
for the optimization of future hybridization experiments directed to the genetic improvement of this economically important
crop. 相似文献
86.
Ana Casas Jose PalomarMaria Virginia Alonso Mercedes OlietSalama Omar Francisco Rodriguez 《Industrial Crops and Products》2012,37(1):155-163
In this work, the solubilities of lignin and cellulose in ionic liquids (ILs) have been analyzed and compared by COSMO-RS simulation. The excess enthalpy of the IL + lignin/cellulose mixtures is evaluated as reference property to describe the affinity of lignin and cellulose for different ionic liquids, in terms of the intermolecular interactions contributing to their mixing properties. Thus, the anion plays the main role in the dissolution process of both lignin and cellulose, in which the hydrogen bonding forces are the major interactions. The most promising anions for the cellulose and lignin dissolution are acetate, formate and chloride, whereas different cations can be employed. Computational results indicated that a rational combination of the anions and cations allows designing ILs able to dissolve with different selectivity lignin and cellulose. Some of these solutions are tested in the laboratory to validate the model employed and the regenerated solids are analyzed by FTIR spectroscopy. 相似文献
87.
Vanina Alemandri María Fernanda Mattio Sandra Mónica Rodriguez Graciela Truol 《European journal of plant pathology / European Foundation for Plant Pathology》2017,149(3):743-750
High Plains wheat mosaic virus (HPWMoV) has recently been assigned to genus Emaravirus and is the causal agent of High Plains disease. In this work the geographical distribution and first molecular detection of HPWMoV in Argentina are reported. The virus was detected in six provinces and nine hosts, including wheat, corn, oat and barley, as well as weeds, which play an important role in the epidemiology of this disease. Molecular and phylogenetic analyses of a portion of RNA3 nucleoprotein gene sequence showed that five HPWMoV isolates from different wheat growing regions of Argentina were identical, and suggest a single introduction of HPWMoV to this country, possibly through corn seeds. To the best of our knowledge, this is the first molecular detection of HPWMoV in South America. These results highlight the importance of certification of viruses-free cereal seeds and strict controls for material transfer between different countries to prevent the entry not only of new pathogens but also of new variants or strain at sites where the pest has already been detected. 相似文献
88.
89.
Participation of phosphofructokinase,malate dehydrogenase and isocitrate dehydrogenase in capacitation and acrosome reaction of boar spermatozoa 下载免费PDF全文
E Breininger D Dubois VE Pereyra PC Rodriguez MM Satorre PD Cetica 《Reproduction in domestic animals》2017,52(5):731-740
The aim of this work was to determine the enzymatic activity of phosphofructokinase (PFK), malate dehydrogenase (MDH) and isocitrate dehydrogenase (IDH) in boar spermatozoa and study their participation in bicarbonate‐induced capacitation and follicular fluid‐induced acrosome reaction. Enzymatic activity of these enzymes was determined spectrophotometrically in extracts of boar spermatozoa. Sperm suspensions were incubated in the presence of bicarbonate (40 mM), a well‐known capacitation inducer, or follicular fluid (30%), as an acrosome reaction inducer, and different concentrations of oxoglutarate, oxalomalate and hydroxymalonate, inhibitors of PFK, IDH and MDH, respectively. Capacitation percentages were determined by the fluorescence technique of chlortetracycline (CTC), and true acrosome reaction was determined by trypan blue and differential–interferential contrast, optical microscopy. The activity of PFK in boar spermatozoa enzymatic extracts was 1.70 ± 0.19 U/1010 spermatozoa, the activity of NAD‐ and NADP‐dependent IDH was 0.111 ± 0.005 U/1010 and 2.22 ± 0.14 U/1010 spermatozoa, respectively, and the activity of MDH was 4.24 ± 0.38 U/1010 spermatozoa. The addition of the specific inhibitors of these enzymes prevented sperm capacitation and decreased sperm motility during capacitation and inhibited the acrosome reaction (AR), without affecting the sperm motility during this process. Our results demonstrate the participation of PFK, IDH and MDH in bicarbonate‐induced capacitation and follicular fluid‐induced acrosome reaction in boar spermatozoa, contributing to elucidate the mechanisms that produce energy necessary for these processes in porcine spermatozoa. 相似文献
90.