全文获取类型
收费全文 | 350篇 |
免费 | 14篇 |
专业分类
林业 | 117篇 |
农学 | 8篇 |
31篇 | |
综合类 | 43篇 |
农作物 | 4篇 |
水产渔业 | 13篇 |
畜牧兽医 | 129篇 |
园艺 | 5篇 |
植物保护 | 14篇 |
出版年
2021年 | 4篇 |
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 16篇 |
2012年 | 8篇 |
2011年 | 13篇 |
2010年 | 11篇 |
2009年 | 8篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 7篇 |
2005年 | 10篇 |
2004年 | 9篇 |
2003年 | 11篇 |
2002年 | 6篇 |
2001年 | 12篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1992年 | 4篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1984年 | 5篇 |
1979年 | 3篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1971年 | 4篇 |
1970年 | 3篇 |
1969年 | 5篇 |
1967年 | 5篇 |
1966年 | 4篇 |
1964年 | 3篇 |
1962年 | 8篇 |
1961年 | 6篇 |
1960年 | 3篇 |
1959年 | 5篇 |
1957年 | 4篇 |
1956年 | 3篇 |
1955年 | 4篇 |
1953年 | 8篇 |
1952年 | 5篇 |
1951年 | 9篇 |
1950年 | 8篇 |
1949年 | 6篇 |
排序方式: 共有364条查询结果,搜索用时 15 毫秒
121.
122.
Douglass K. Macintire DVM MS Ralph A. Henderson DVM MS Eric R. Wilson DVM Michael L. Huber DVM 《Journal of Veterinary Emergency and Critical Care》1995,5(1):25-31
A technique is described which is particularly useful in obese or heavily muscled animals when a single lumen tracheostomy tube is used, or when mechanical ventilation through a cuffed tracheostomy tube is required. The technique assures easy access to a large tracheal stoma which facilitates cleaning and tube replacement. 相似文献
123.
A J Kaneps T W Riebold W B Schmotzer B J Watrous M J Huber 《Journal of the American Veterinary Medical Association》1989,194(4):547-548
Unilateral congenital medial patellar luxation in a young llama was corrected by medial joint capsule release, tibial crest transposition, trochleoplasty, and lateral joint capsule imbrication. The techniques used were the same as described in the dog. One year after surgery, the llama was not lame, but had a valgus deformity originating at the stifle, most likely caused by lateral femoral condyle hypoplasia. 相似文献
124.
D.M. Huber 《Soil Use and Management》1990,6(4):168-172
Abstract. Nutrient manipulation through fertilization or modification of the soil environment to influence nutrient availability is an important cultural control for plant disease and an integral component of production agriculture. Fertilization decreases soil-borne diseases by maximizing the inherent disease resistance of plants, by facilitating disease escape through increased nutrient availability or stimulated plant growth, and by altering the external environment to influence the survival, germination and penetration of pathogens. The flexibility in most disease-nutrient interactions permits a much broader utilization of this cultural control in decreasing disease severity than is presently practised. It is clear that the severity of most diseases can be decreased and the chemical, biological or genetic control of many plant pathogens enhanced by proper fertilization. Breeding nutrient-efficient or disease-tolerant crops and establishing cultivar requirements should further improve production efficiency. 相似文献
125.
Litters of pigs were allotted to one of three dietary treatments. Treatment 1 (T1) consisted of a corn-soybean meal starter diet. Pigs fed treatment 2 (T2) received a steamed, rolled oat groats-casein diet and pigs in treatment 3 (T3) remained with the sow. Four pigs/treatment were used to investigate the difference in performance and the cause of post-weaning diarrhea associated with early weaning of pigs at 4 wk of age to a starter diet. Fecal moisture, osmolarity, acetic acid, lactic acid and glucose contents were all good indicators of dietary differences because of treatment X age interactions. These variables increased faster in fecal extracts from pigs fed the corn-soybean meal diet. Lactic acid, volatile fatty acid (VFA) levels, glucose and pH values were indicative of a more active bacterial fermentation in pigs receiving T1 than in those receiving T2 or pigs remaining with the sow (T3). Excess minerals appear to contribute significantly to the osmolarity of fecal material. Of the anions, lactate was the main contributor to the osmolarity of feces of T1 pigs, followed by P, VFA, of which acetic acid contributed 70%, and Cl. The main cations were K, Na and Ca. In T2, P was the main anion, followed by lactate, VFA and Cl, while the main cations were Na, K and Ca. Minerals seemed to be the major osmotic particles in fecal extracts of pigs remaining with the sow. Phosphorus was the major anionic contributor to osmolarity, followed by VFA, Cl and lactic acid. Potassium was the major cation, followed by Na and Ca.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
126.
Dorothy P. Laflamme Edward A. Mahaffey Sheila W. Allen David C. Twedt Keith W. Prasse Thomas L. Huber Phd 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(3):212-216
Microcytosis is common in dogs with congenital portosystemic shunts (PSS) and acquired liver disease. The objective of this study was to determine if microcytosis could be induced in normal dogs by surgical creation of PSS, and to characterize the changes in hematology and iron status. Hematocrit, mean cell volume, mean cell hemoglobin, and mean cell hemoglobin concentration decreased linearly from 45.5%. 69.1 fL, 22.8 g/dL and 33.1% to 39.5%. 55.9 fL, 17.8 g/dL and 31.9%. respectively, 18 weeks after creation of PSS. The erythrocyte count did not change, but red cell distribution widths indicated a shift to a heterogenous population with decreased volume. Mean cell volume and mean cell hemoglobin decreased rapidly after induction of PSS and were significantly ( P < .05) different from presurgery values within 2 weeks. Serum iron and copper concentrations and total iron binding capacity were decreased in dogs with PSS. Liver iron concentration doubled after creation of PSS, with the majority of stainable iron located in Kupffer cells. The changes in erythrocyte indices and measures of iron status in dogs with surgically induced PSS were similar to those in dogs with congenital PSS. Microcytosis developed rapidly in dogs after induction of PSS. These results indicate that iron deficiency was not the cause of microcytosis in these dogs. 相似文献
127.
The purpose of the present study was the genetic characterization, sequencing and phylogenetic analysis of 18S rDNA sequences of Cryptosporidium isolates obtained from different animal hosts in Brazil. Fecal samples containing Cryptosporidium oocysts were obtained from chickens, ducks, quails, guinea pigs, dairy calves, dogs and cats. For amplification of 18S rDNA sequences the Secondary-PCR product of the extracted DNA from fecal suspension of each studied animal was utilized. The primary genetic characterization of Cryptosporidium sp. was performed using RFLP with the enzymes SspI and VspI. DNA samples were sequenced and subjected to phylogenetic analysis. The results showed C. baileyi infecting two ducks and one quail and C. melagridis infecting one chicken. The sequences obtained from Cryptosporidium sp. infecting guinea pigs were not identified within groups of known Cryptosporidium species. The isolates found parasitizing cats and one dog were diagnosed as C. felis and C. canis, respectively. One isolate of calf origin was identified as C. parvum. The phylogenetic analysis showed clear distribution of isolates between two Cryptosporidium sp. groups according to their gastric or intestinal parasitism. A great genetic distance was observed between C. felis and C. canis from Brazil when compared to the reference sequences obtained from GenBank. The results obtained during this study constitute the first report of rDNA sequences from C. baileyi, C. meleagridis, C. felis, C. canis and C. parvum isolated in Brazil. 相似文献
128.
FM Rodríguez M Colombero AN Amweg E Huber NC Gareis NR Salvetti HH Ortega F Rey 《Reproduction in domestic animals》2015,50(4):659-668
Cystic ovarian disease (COD) is one of the main causes of infertility in dairy cattle. It has been shown that intra‐ovarian factors, such as members of the insulin‐like growth factor (IGF) system, may contribute to follicular persistence. The bioavailability of IGF to initiate its response by binding to specific receptors (IGFRs) depends on interactions with related compounds, such as pregnancy‐associated plasma protein A (PAPP‐A). The aim of this study was to determine IGFR1 and PAPP‐A expression both in follicles at different stages of development and in cysts, to evaluate the roles in the etiopathogenesis of COD in cattle. The mRNA expression of PAPP‐A was higher in granulosa cells of large tertiary follicles than in cysts, whereas the protein PAPP‐A present in the follicular fluid from these follicles showed no differences. Although no PAPP‐A mRNA expression was detected in smaller tertiary follicles, in their follicular fluid, this protease was detected in lesser concentration than in cysts. The mRNA expression of IGFR1 was lower in granulosa cells from cystic follicles than in those from tertiary ones. However, the protein expression of this receptor presented the highest levels in cystic structures, probably to increase the possibility of IGF response. The data obtained would indicate that animals with COD have an altered regulation of the IGF system in the ovary, which could be involved in the pathogenesis of this disease in cattle. 相似文献
129.
Angela I. Bordin Laura Huber Macarena G. Sanz Noah D. Cohen 《Equine veterinary journal》2022,54(3):481-494
Pneumonia in foals caused by the bacterium Rhodococcus equi has a worldwide distribution and is a common cause of disease and death for foals. The purpose of this narrative review was to summarise recent developments pertaining to the epidemiology, immune responses, treatment, and prevention of rhodococcal pneumonia of foals. Screening tests have been used to implement earlier detection and treatment of foals with presumed subclinical R. equi pneumonia to reduce mortality and severity of disease. Unfortunately, this practice has been linked to the emergence of antimicrobial-resistant R. equi in North America. Correlates of protective immunity for R. equi infections of foals remain elusive, but recent evidence indicates that innate immune responses are important both for mediating killing and orchestrating adaptive immune responses. A macrolide antimicrobial in combination with rifampin remains the recommended treatment for foals with R. equi pneumonia. Great need exists to identify which antimicrobial combination is most effective for treating foals with R. equi pneumonia and to limit emergence of antimicrobial-resistant strains. In the absence of an effective vaccine against R. equi, passive immunisation remains the only commercially available method for effectively reducing the incidence of R. equi pneumonia. Because passive immunisation is expensive, labour-intensive and carries risks for foals, great need exists to develop alternative approaches for passive and active immunisation. 相似文献
130.
Asser-Kaiser S Fritsch E Undorf-Spahn K Kienzle J Eberle KE Gund NA Reineke A Zebitz CP Heckel DG Huber J Jehle JA 《Science (New York, N.Y.)》2007,317(5846):1916-1918
Insect-specific baculoviruses are increasingly used as biological control agents of lepidopteran pests in agriculture and forestry, and they have been previously regarded as robust to resistance development by the insects. However, in more than a dozen cases of field resistance of the codling moth Cydia pomonella to commercially applied C. pomonella granulovirus (CpGV) in German orchards, resistance ratios exceed 1000. The rapid emergence of resistance is facilitated by sex-linkage and concentration-dependent dominance of the major resistance gene and genetic uniformity of the virus. When the gene is fixed, resistance levels approach 100,000-fold. Our findings highlight the need for development of resistance management strategies for baculoviruses. 相似文献