全文获取类型
收费全文 | 164篇 |
免费 | 11篇 |
专业分类
林业 | 15篇 |
农学 | 3篇 |
基础科学 | 5篇 |
23篇 | |
综合类 | 17篇 |
农作物 | 6篇 |
水产渔业 | 7篇 |
畜牧兽医 | 75篇 |
园艺 | 2篇 |
植物保护 | 22篇 |
出版年
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 4篇 |
2017年 | 8篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 9篇 |
2012年 | 12篇 |
2011年 | 18篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 9篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 9篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 3篇 |
1926年 | 2篇 |
1925年 | 3篇 |
排序方式: 共有175条查询结果,搜索用时 15 毫秒
1.
2.
3.
Schawalder P Andres HU Jutzi K Stoupis C Bösch C 《Schweizer Archiv für Tierheilkunde》2002,144(3):115-130
Panosteitis, an idiopathic bone disease of young dogs, was investigated in the light of a new, empirically based hypothesis governing its pathogenesis. Extensive clinical observations suggest a close relationship between the incidence of this disease and the commercialization of various protein-rich, high-calorie dog foods. The theory of an "osseous compartment syndrome" provides a hypothetical pathogenesis, which corroborates this findings. An excessive accumulation of protein causes intraosseous edema due to its osmotic effects. Because bone is a rigid compartment, this leads to an increase in intramedullary pressure and compression of blood vessels. Subsequent osseous ischemia leads to a deficient metabolic state (decreased oxygenation, inadequate influx of nutritive substances, local acidosis, decreased removal of metabolites, disruption of local biochemical processes, etc.), and a vicious circle is created due to the resulting local inflammation. The disease is aggravated by increased metabolism due to excessive physical activity. Within the context of a pilot study, clinical, radiographic, scintigraphic and thermographic examinations and a therapeutic trial with benzopyron were carried out. In addition, more modern investigative tools, including osteomyelography, magnetic resonance tomography and intraosseous pressure measurements were used to provide objective data concerning the pathogenesis of panosteitis. In most cases, clinical remission was seen within days of monotherapy with the proteolytic substance, benzopyron (Cumartrin). This finding appears to corroborate our hypothesis. 相似文献
4.
5.
Use of spatial statistics and monitoring data to identify clustering of bovine tuberculosis in Argentina 总被引:2,自引:0,他引:2
The spatial distribution of endemic bovine tuberculosis (TB) in Argentine cattle herds was described using recorded information on the detection of TB-like lesions in cattle slaughtered between March 1995 and 1997 at 126 slaughterhouses with federal inspection. Approximately, 47% (9472396 cattle) of the estimated total number of cattle slaughtered in Argentina during this period was included in the study. Information on the number of cattle per source herd consigned to slaughter, number of cattle with TB-like lesions per herd and the geographical location of counties from which cattle originated was used to investigate spatial clustering of TB. Overall, no evidence of clustering of TB prevalence by county was detected (Moran's autocorrelation statistic I=0.009, P=0.089). However, first- (Cuzick and Edwards' test statistic, T(k)=87, P=0.036) and second-order (T(k)=170, P=0.038) nearest-neighbor case-counties (TB prevalence>median prevalence of all counties, 6.7%) were clustered. Using the spatial scan test based on a Bernoulli model, the most-likely cluster (P=0.001) identified during the study period included 5793 cases of TB (5.2 per 1000 km(2)) in five counties. This cluster coincided with Santa Fe Province, which contains 21% of all dairy cows in Argentina and accounts for 34% of the country's milk production. Several secondary clusters of TB-also located in dairy districts-were identified. Study results demonstrate that bovine TB is clustered in Argentina, and these clusters coincide with dairy cattle production. Identification of clustering can assist efforts to eradicate bovine TB from Argentina. Further spatial investigations need to focus on the reasons why TB is clustered in Argentina. In particular, the relationship between TB clustering and management practices-such as grazing density and production systems-need to be described to assist in the development of disease-control programs. The use of spatial statistics and geographical information systems could meet these needs. 相似文献
6.
Simulation model of within-herd transmission of bovine tuberculosis in Argentine dairy herds 总被引:7,自引:0,他引:7
Transmission of bovine tuberculosis was quantified in three dairy herds located in south Santa Fe Province, Argentina. Using estimates of Mycobacterium bovis transmission (β) and a Reed–Frost simulation model, the prevalence of tuberculosis infection in the study herds over time was investigated. The Reed–Frost model was modified by incorporating randomness in both β and the incubation period () of M. bovis. The mean estimated herd β was 2.2 infective contacts per year and did not differ significantly between the study herds. Modeling as Poisson distributed (mean 24 months) best fit the observed prevalences. Infection was predicted by the model either to spread quickly (<10 years) within a herd and reach a high prevalence (>50%), or to persist at a low prevalence (<5–10%). The model was robust, predictions were realistic and the mean β estimated was consistent with previous studies of bovine tuberculosis. 相似文献
7.
Barbara Thuerig Andres Binder Thomas Boller Urs Guyer Sonia Jiménez Christina Rentsch Lucius Tamm 《European journal of plant pathology / European Foundation for Plant Pathology》2006,114(2):185-197
We have examined the effect of Pen, an aqueous extract of the dry mycelium of Penicillium chrysogenum, on plant–pathogen interactions. Pen controlled a broad range of pathogens on several crop plants under greenhouse and field
conditions. Pen protected grapevine from downy and powdery mildew (caused by Plasmopara viticola and Uncinula necator), tomato from early blight (caused by Phytophthora infestans), onion from downy mildew (Peronospora destructor) and apple trees from apple scab (caused by Venturia inaequalis) to a similar extent as fungicides such as copper and sulphur or well-known inducers such as benzothiadiazole or β-aminobutyric
acid. Pen had no major direct fungicidal effect and is thus supposed to protect plants by activating their defense mechanisms.
The raw material for extraction of Pen was available in constant quality, a prerequisite for commercial application. Under
certain conditions, Pen caused phytotoxic side effects. The symptoms mostly consisted of small necrotic spots or, more rarely,
of larger necrotic areas. The development of the symptoms was dependent on several parameters, including concentration of
Pen, the number of applications, the persistence on the plant tissue, the plant species and variety and environmental conditions.
In grapevine, a partially purified fraction of Pen was much less toxic than the crude Pen extract, but protected the plants
to a similar extent against P. viticola. Our data show that Pen has interesting and unique properties as a plant protection agent, but more research is needed to
further reduce its phytotoxic side effects. 相似文献
8.
Ed Kabara Lorraine M. SordilloSue Holcombe G. Andres Contreras 《Comparative immunology, microbiology and infectious diseases》2014
The periparturient period of dairy cows is characterized by intense lipid mobilization from adipose tissue leading to increased plasma concentrations of nonesterified fatty acids (NEFA). High NEFA are a predisposing factor for inflammatory based diseases. A major component of these diseases is uncontrolled macrophage/monocyte inflammatory responses. Changes in the endocrine activity of adipose tissue during the periparturient period could impact macrophage function by modifying the secretion of adipokines including adiponectin. Currently, the effects of adiponectin on monocyte activation in dairy cattle are unknown. In humans and rodents, this adipokine regulates monocyte phenotype and alterations in its plasma levels are linked with the development of inflammatory diseases. The objectives of this study were to establish associations between plasma adiponectin expression dynamics and different markers of lipid mobilization during the periparturient period of dairy cows and to characterize the effects of adiponectin on the inflammatory response of bovine monocytes. Plasma adiponectin, NEFA, BHB, albumin, and subcutaneous and retroperitoneal fat depots depth were measured during the periparturient period of dairy cows. In vitro, bovine monocytes were cultured with adiponectin to assess changes in pro-inflammatory responses following LPS stimulation. Results from this study demonstrate that alterations in plasma adiponectin levels in periparturient cattle are inversely correlated with the concentrations of plasma NEFA, an important marker of lipid mobilization. Furthermore, adiponectin exposure significantly decreased monocyte expression of TNFα after LPS stimulation thus markedly reducing their inflammatory response. Reduced plasma adiponectin during the periparturient period could predispose dairy cows to the development of uncontrolled monocyte inflammatory responses. 相似文献
9.
Ambros L Montoya L Kreil V Waxman S Albarellos G Rebuelto M Hallu R San Andres MI 《Journal of veterinary pharmacology and therapeutics》2007,30(1):80-85
The objectives of this work were to compare the pharmacokinetics of erythromycin administered by the intramuscular (i.m.) and intravenous (i.v.) routes between nonlactating and lactating goats and to determine the passage of the drug from blood into milk. Six nonpregnant, nonlactating and six lactating goats received erythromycin by the i.m. (15 mg/kg) and the i.v. (10 mg/kg) routes of administration. Milk and blood samples were collected at predetermined times. Erythromycin concentrations were determined by microbiological assay. Results are reported as mean +/- SD. Comparison of the pharmacokinetic profiles between nonlactating and lactating animals after i.v. administration indicated that significant differences were found in the mean body clearance (8.38 +/- 1.45 vs. 3.77 +/- 0.83 mL/kg x h respectively), mean residence time (0.96 +/- 0.20 vs. 3.18 +/- 1.32 h respectively), area under curve from 0 to 12 h (AUC(0-12)) (1.22 +/- 0.22 vs. 2.76 +/- 0.58 microg x h/mL respectively) and elimination half-life (1.41 +/- 1.20 vs. 3.32 +/- 1.34 h); however, only AUC(0-12) showed significant differences after the i.m. administration. Passage of erythromycin in milk was high (peak milk concentration/peak serum concentration, 2.06 +/- 0.36 and AUC(0-12milk)/AUC(0-12serum),6.9 +/- 1.05 and 2.37 +/- 0.61 after i.v. and i.m. administrations respectively). We, therefore, conclude that lactation affects erythromycin pharmacokinetics in goats. 相似文献
10.