全文获取类型
收费全文 | 276篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
林业 | 7篇 |
60篇 | |
综合类 | 51篇 |
农作物 | 26篇 |
水产渔业 | 16篇 |
畜牧兽医 | 115篇 |
植物保护 | 10篇 |
出版年
2021年 | 6篇 |
2020年 | 9篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 22篇 |
2012年 | 12篇 |
2011年 | 12篇 |
2010年 | 6篇 |
2009年 | 4篇 |
2008年 | 10篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 11篇 |
2001年 | 11篇 |
2000年 | 11篇 |
1999年 | 4篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 5篇 |
1973年 | 3篇 |
1972年 | 8篇 |
1971年 | 2篇 |
1970年 | 3篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1928年 | 4篇 |
1924年 | 1篇 |
1895年 | 1篇 |
1890年 | 1篇 |
1881年 | 1篇 |
排序方式: 共有285条查询结果,搜索用时 421 毫秒
71.
72.
1. An experiment was conducted with Large White turkey poults (0 to 3 weeks of age) to study the influence of dietary fillers on the true metabolisable energy (TME) of the diet.
2. When 25 g sand/kg was substituted for the components of a basal diet, growth was not affected and the TME value of the diet was apparently higher than that of the basal diet, but not significantly so.
3. The substitution of 50 g filler/kg (25 g sand plus 25 g grit/kg) resulted in a higher TME value than the substitution of either 25 g sand/kg or 25 g grit/kg, significantly so in the latter case.
4. Substituting 25 g cellulose/kg resulted in a decrease in TME value, but not significantly so. 相似文献
73.
Jonnie E. Quantz DVM Macon S. Miles DVM DACVIM Ann L. Reed DVM DACVR George A. White DVM DACVECC 《Journal of Veterinary Emergency and Critical Care》2009,19(6):536-544
Objective – The purpose of the study was to evaluate alanine transaminase (ALT) and gallbladder wall abnormalities as possible biomarkers for anaphylaxis in dogs presented for acute hypersensitivity reactions. Design – Pilot study. Setting – A private practice, small animal, 24‐hour emergency and specialty hospital. Animals – Ninety‐six dogs presenting 101 times on an emergency basis for hypersensitivity reactions from March 2007 through March 2009. Interventions – Veterinarians acquired a history, physical exam, serum chemistry panel, blood pressure, and ultrasound image of the gallbladder. Measurements and Main Results – Dogs were then divided into 2 groups: dogs fulfilling the definition for anaphylaxis (moderate and severe systemic hypersensitivity) and dogs that did not fulfill the definition and were classified as allergic reactions (local hypersensitivity and mild systemic hypersensitivity). Elevated ALT was significantly associated with anaphylaxis (P<0.001). Increased gallbladder wall thickness and a striated wall pattern were significantly associated with anaphylaxis (P<0.001) and these changes were readily apparent to first‐responder veterinarians. Decreased body temperature (P<0.001) and hypothermia (P=0.006) were significantly associated with anaphylaxis. There was no significant difference between groups regarding age, heart rate, or presence of respiratory signs. Lower blood pressure was significantly associated with anaphylaxis (P<0.001) but hypotension was not significantly different (P=0.09) between groups. Cutaneous signs were significantly associated with the allergic reactions group (P<0.001) and, when seen with anaphylaxis, were subtle. Conclusions – This study showed an elevated ALT and an abnormal gallbladder wall to be biomarkers significantly associated with anaphylaxis in dogs with acute hypersensitivity reactions. 相似文献
74.
Anthracnose fruit rot is an important disease of blueberries, and losses are common in humid growing regions. Most commercial cultivars are susceptible and the disease is usually managed with fungicides. However, a few cultivars are considered resistant. The objectives of this study were to: (i) compare different inoculation techniques for anthracnose fruit rot resistance screening, (ii) screen ripe fruit from a range of blueberry cultivars using selected techniques, and (iii) investigate the role of fruit characteristics in anthracnose fruit rot resistance. The following inoculation methods were evaluated on ripe fruit of a susceptible and resistant cultivar using a conidial suspension: spray, droplet, and injection inoculation of whole fruit; and droplet inoculation of the open surface of cut fruit. All whole‐fruit inoculations yielded similar results. Despite the removal of the epidermis, resistance was also expressed in cut fruit but relatively fewer conidia were produced. The cut‐fruit assay required substantially less time and half the amount of fruit to accomplish than whole‐fruit assays. Detached ripe fruit from 24 cultivars in 2008 and 26 cultivars in 2009 were screened for resistance. Results from the cut‐fruit assay correlated best with published resistance ratings. To determine the possible role of fruit characteristics in resistance, fruit pH, titratable acidity, sugar content and firmness were regressed against various fruit rot resistance measures. Fruit rot resistance was positively correlated with sugar content. On defined media, mycelial growth was restricted as sugar concentration increased and pH decreased, suggesting that fruit composition may play a role in the resistance phenotype. 相似文献
75.
76.
77.
Hydrogen peroxide (H2O2) production and oxygen uptake during the oxidation of NADH and L-alpha-glycerophosphate (GP) by lysed cells was determined for the type and field strains of Mycoplasma bovis and M. agalactiae. NADH oxidation by all the strains showed variable production of H2O2 ranging from 0 to 1.21 mol/mol O2 taken up. All strains were unable to oxidize GP, showing absence of GP oxidase activity. Some strains were identified that produced relatively high levels of H2O2 (> 1.0 mol/ mol O2 taken up). In vitro passage of M. bovis strain 119B96 showed reduced H2O2 production: 0.52, 0.16, and 0.07 mol/mol O2 taken up after the 50th, 100th and 200th passages, respectively. SDS-PAGE analysis showed the loss of a protein band of 32 kDa after 50 passages. These preliminary studies show that not only does H2O2 production by potentially pathogenic Mycoplasma spp. vary in the field but also that similar alterations can be induced by passage in culture. In the latter case, at least in one M. bovis strain, this alteration has been shown by SDS-PAGE to be associated with a loss of specific protein production. Further study of these phenomena is essential background for the production of more efficient vaccines for mycoplasmas. 相似文献
78.
Mycoplasma equigenitalium and Mycoplasma subdolum have been associated with infertility, endometritis, vulvitis and abortions in mares, and with reduced fertility and balanoposthitis in stallions. Despite their role in equine genital disorder, determinants of virulence and pathogenesis as well as factors provoking specific host immune responses have not been identified, so far. To establish the major immunogenic components of Mycoplasma (M.) equigenitalium and M. subdolum, antigen profiles of their type strains as well as 30 clinical isolates were compared by SDS-PAGE and immunoblot analysis using hyperimmune rabbit sera and equine sera from clinical cases. To define the major protein antigens of both mycoplasma species, detergent-phase fractionation with Triton X-114 was performed. Western blot analysis of 30 clinical isolates revealed a high similarity of their overall antigen profile with only slight differences. In contrast, monospecific polyclonal antibodies raised against detergent-phase proteins of the two mycoplasma species identified three prominent proteins (pST17, pST42, and pET45) undergoing variation in expression and size among clinical and clonal isolates. 相似文献
79.
Khan LA Loria GR Ramirez AS Nicholas RA Miles RJ Fielder MD 《Veterinary microbiology》2005,109(1-2):129-134
The pattern and kinetics of substrate oxidation by type and recent field strains of Mycoplasma agalactiae, Mycoplasma bovis, Mycoplasma bovigenitalium and Mycoplasma ovine/caprine serogroup 11 were investigated by measurement of oxygen uptake. Metabolism of a range of organic acids, sugars and alcohols was detected. All the test strains were unable to oxidise sugars, glycerol and the organic acids, fumarate, malate and alpha-ketoglutarate (1 mM). All strains oxidised organic acid l-lactate, 2-oxobutyrate and pyruvate and demonstrated the ability to oxidise alcohols, particularly isopropanol, which was oxidised at a high rate and high affinity (0.5 mol/mol isopropanol). Its oxidation was consistent with acetone formation, which may be of important in relation to pathogenicity. All strains oxidised similar substrates, however differences were observed between strains in terms of the relative rates and kinetic values for some substrates. 相似文献
80.
A tension band technique was used in conjunction with a transarticular pin to stabilise 24 sacroiliac separations in 19 cats. The authors suggest that this technique is simpler and safer than the transarticular screw technique, and as effective. 相似文献