全文获取类型
收费全文 | 821篇 |
免费 | 44篇 |
专业分类
林业 | 63篇 |
农学 | 22篇 |
59篇 | |
综合类 | 49篇 |
农作物 | 17篇 |
水产渔业 | 26篇 |
畜牧兽医 | 603篇 |
园艺 | 2篇 |
植物保护 | 24篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 11篇 |
2019年 | 19篇 |
2018年 | 13篇 |
2017年 | 20篇 |
2016年 | 19篇 |
2015年 | 21篇 |
2014年 | 23篇 |
2013年 | 42篇 |
2012年 | 53篇 |
2011年 | 40篇 |
2010年 | 24篇 |
2009年 | 13篇 |
2008年 | 43篇 |
2007年 | 39篇 |
2006年 | 57篇 |
2005年 | 34篇 |
2004年 | 38篇 |
2003年 | 31篇 |
2002年 | 24篇 |
2001年 | 48篇 |
2000年 | 36篇 |
1999年 | 33篇 |
1998年 | 8篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 23篇 |
1991年 | 15篇 |
1990年 | 18篇 |
1989年 | 13篇 |
1988年 | 18篇 |
1987年 | 16篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 9篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1974年 | 1篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1963年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有865条查询结果,搜索用时 15 毫秒
861.
862.
Prognosis of canine patients with nasal tumors according to modified clinical stages based on computed tomography: a retrospective study 总被引:1,自引:0,他引:1
Kondo Y Matsunaga S Mochizuki M Kadosawa T Nakagawa T Nishimura R Sasaki N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(3):207-212
To evaluate the efficacy of clinical staging based on computed tomography (CT) imaging over the World Health Organization (WHO) staging system based on radiography for nasal tumors in dogs, a retrospective study was conducted. This study used 112 dogs that had nasal tumors; they had undergone radiography and CT and had been histologically confirmed as having nasal tumors. Among 112 dogs, 85 (75.9%) were diagnosed as adenocarcinoma. Then they were analyzed for survival time according to each staging system. More than 70% of the patients with adenocarcinoma were classified as having WHO stage III. The patients classified under WHO stage II tended to survive longer than those classified under WHO stage III. Dogs classified under WHO stage III were further grouped into CT stages III and IV, and CT stage III patients had a significantly longer survival time than CT stage IV patients. In addition, patients treated with a combination of surgery and radiation had a significantly longer survival time than the patients who did not receive any treatment in CT stage III. On the other hand, different treatment modalities did not show a significant difference in the survival time of CT stage IV dogs. The results suggest that WHO stage III dogs may have various levels of tumor progression, indicating that the CT staging system may be more accurate than the WHO staging system. 相似文献
863.
Sasaki K Azuma T Kawabata K Umemura S Tanaka R Yamane Y Shimoda M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(8):839-845
The treatment time needed for high-intensity focused ultrasound (HIFU) ablation might be decreased substantially by using the split-focus approach, so we made a prototype 4.2-MHz split-focus therapeutic transducer combined with a small 6.5-MHz imaging ultrasonic probe for transrectally treatment of canine prostatic cancer and used it to experimentally evaluate the feasibility of using split-focus transrectal HIFU to ablate canine prostatic tissue without injuring surrounding tissues. The prostates of 5 dogs were transrectally treated with split-focus ablation at a peak intensity in the water of 1.7 kW/cm(2) for 4 s (4 shots) under the guidance of ultrasonic B-mode imaging. After ultrasonic exposure, the prostates became stiff because of thermal effect of HIFU. For the first 3-5 days after treatment, dogs were catheterized daily for urinary management and treated with oral antibiotics to prevent urinary tract infection. The dogs were able to urinate normally by a week after. Within two weeks a large centrally located cystic cavity had formed in the prostate by replacing the necrotic parenchyma around the prostatic urethra. Necropsy three months after treatment found the rectum and prostate capsule to be normal grossly and histologically. The 4 shots of split-focus HIFU destroyed the prostatic parenchyma and created a prostatic cavity 0.34-0.45 cm(3) in volume without injuring surrounding tissues. These results suggest that split-focus HIFU ablation could be used for noninvasive treatment of prostatic cancer in dogs. 相似文献
864.
Yamamoto K Sasaki Y Ogikubo Y Noguchi N Sasatsu M Takahashi T 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2001,48(4):293-301
This is the first report to demonstrate the presence of tet(M) in naturally occurring isolates of tetracycline-resistant Erysipelothrix rbusiopathiae, which causes swine erysipelas. The tet(M) gene was isolated from E. rhusiopathiae strain KY5-42. The nucleotide and the deduced amino acid sequence were 99% identical to the tet(M) gene from Enterococcus faecalis. The gene was necessary and sufficient for the expression of tetracycline resistance in Escherichia coli. The presence of the tet(M) gene in the 114 tetracycline-resistant E. rhusiopathiae isolates from diseased pigs was detected by the polymerase chain reaction assay. The specific amplified DNA fragment was obtained from all 114 tetracycline-resistant strains. It was suggested that the tet(M) gene was widely present in the field isolates of E. rhusiopathiae resistant to tetracycline. 相似文献
865.
The effects of environmental temperature on gelatinization properties and amylopectin structures of wheat endosperm starch were examined by isolating starches from four wheat cultivars matured in growth chambers at daytime temperatures of 15, 20, 25, or 30°C. Kernel weight and starch content per kernel were reduced by high maturation temperature. Amylose content showed no significant change at high maturation temperature in some cultivars; in other cultivars, there was a slight increase. Principal component analysis of data on relative peak areas of debranched amylopectin showed that amylopectin from wheat grown at a lower temperature had a greater proportion of shorter chains. Amylopectin branch chains were classified into three groups based on the correlation coefficients between the data of branch chain length distribution and principal component scores, degree of polymerization (DP) of 6–12, DP 13–34, and DP ≥ 35. The gelatinization temperature of starches increased markedly at a higher maturation temperature, with increases exceeding 10°C at high maturation temperatures. Gelatinization properties correlated significantly with amylopectin chain length distribution. 相似文献