全文获取类型
收费全文 | 201篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
林业 | 2篇 |
26篇 | |
综合类 | 7篇 |
农作物 | 2篇 |
水产渔业 | 19篇 |
畜牧兽医 | 139篇 |
园艺 | 1篇 |
植物保护 | 6篇 |
出版年
2022年 | 14篇 |
2021年 | 16篇 |
2020年 | 4篇 |
2016年 | 7篇 |
2015年 | 18篇 |
2014年 | 21篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 8篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 11篇 |
2005年 | 9篇 |
2004年 | 7篇 |
2003年 | 14篇 |
2002年 | 11篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1994年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1963年 | 1篇 |
1958年 | 1篇 |
1954年 | 1篇 |
1953年 | 1篇 |
1950年 | 1篇 |
1946年 | 1篇 |
排序方式: 共有202条查询结果,搜索用时 718 毫秒
101.
Abstract. A vaccine solution of a formalin-killed culture of Vibrio anguillarum cells was observed to be toxic to young ayu when administered by the hyperosmotic infiltration method. The toxin was present in the culture broth. After the toxin was removed from the broth by centrifugation, the fish were dipped in 5.32% NaCl solution for 2 min and then in a solution containing precipitated cells for 3 min. The immunized fish were protected against vibriosis when challenged one month after immersion. The bacterin was administered to ayu by a further two methods, both using lyophilized whole cells of formalin-killed V. anguillarum. In one method, the fish were placed in a 5.32% NaCl solution for 2 min and then in a solution containing lyophilized cells at 2 g/l of well water for 3 min (two-step immersion). In the other method, the fish were placed in a 5.32% NaCl solution containing lyophilized cells also at 2 g/l for 3 min (one-step immersion). A high level of protection against artificial challenge was achieved with either method. No agglutinating antibodies to V. anguillarum were detected in either the serum or mucus of fish dipped in a vaccine solution, a supernatant, or a precipitated solution, one month after immersion. On the other hand, serum titres were detected in fish vaccinated by injection, although no titres were detected in mucus. LD50 values are presented for the virulence of the V. anguillarum strain. Compared to the original strain, virulence increased after the third passage in ayu, but decreased after the thirteenth passage in medium. 相似文献
102.
Canopy structure, productivity and their relationships were examined in 2-year-old swards of fourteen tall fescue ( Festuca arundinacea Schreb.) strains during the vegetative and reproductive growth stages. During the vegetative growth stage morphological characters, particularly tiller size, were closely associated with productivity. Swards with large tillers showed an effective distribution of the incoming light energy within the canopy and hence low extinction coefficient ( K ) value and high productivity at complete light interception. On the other hand, although there was no apparent correlation between K and the productivity or the whole crop during the reproductive growth stage, the productivities of the reproductive and vegetative tillers were positively and negatively related to K respectively. Leaf area index of the reproductive tillers and their position in the canopy had marked effects on the distribution of the incoming light energy within the canopy and on the productivity of both types of tillers. The productivity of the vegetative and the reproductive tillers is discussed in terms of the effect of the competition for incoming light energy between both types of tillers. 相似文献
103.
104.
Tomokazu OHTA Katsuo KOSHI Koichi USHIZAWA Misa HOSOE Toru TAKAHASHI Takahiro YAMAGUCHI Keiichiro KIZAKI Kazuyoshi HASHIZUME 《The Journal of reproduction and development》2013,59(6):507-511
T cells are the dominant lymphocytes in the endometrium and are considered to play a
crucial role in implantation and in the maintenance of gestation through cytokine
production and immune regulation. The mechanisms underlying immunoregulation at the
feto-maternal interface are still obscure for this complex system. Understanding the
role of T cells is a key factor in understanding the endometrial immune system. In
this study, the distribution of endometrial CD3+ T cells in bovines was
examined by immunohistochemical analysis. The estrous cycle and gestation was divided
into 4 stages, and the number of CD3+-positive T cells was counted in each
stage. CD3+ cells were found in the endometrium in significant numbers
throughout the estrous cycle and were mostly located in the subepithelial area. The
number of CD3+ cells significantly increased in the early and mid-luteal
phases but decreased after implantation with the progression of gestation. No T cells
were found in the placentome or specifically in the tissues near the fetus, including
the trophoblastic area. In addition, very few T cells were found in stromal regions
close to the myometrium of the endometrium. These findings suggest that
downregulation of bovine endometrial CD3+ T-cell functions is closely
related to the successful maintenance of gestation in a spatiotemporal manner. 相似文献
105.
106.
107.
108.
Zeenat Ara LILA Nazimuddin MOHAMMED Tsuyoshi TAKAHASHI Masahiko TABATA Takashi YASUI Mitsunori KURIHARA Shuhei KANDA Hisao ITABASHI 《Animal Science Journal》2006,77(4):407-413
This experiment was designed to investigate the effects of different concentrations of cellobiose (CB) or a twin strain of Saccharomyces cerevisiae live cells (YST) (20, 40 and 60 mg/60 mL), and CB + YST (60 + 20, 60 + 40, 60 + 60 mg/60 mL) on mixed ruminal microorganism fermentation in vitro. Ruminal fluid was collected from a cow, mixed with phosphate buffer (1:2) and incubated (60 mL) anaerobically at 38°C for 24 h with or without supplement plus 400 mg (dry matter [DM] basis) substrate (hay plus concentrate, 1.5:1). The medium pH numerically decreased with CB and CB + YST, but was unchanged with YST. The total volatile fatty acid and proportion of propionate increased (P < 0.05) in all cases. The proportion of acetate decreased (P < 0.05) with CB and CB + YST, but increased (P < 0.05) with YST and that of butyrate increased (P < 0.05) with CB and CB + YST, but decreased (P < 0.05) with YST. Ammonia‐N decreased (P < 0.05) with CB and CB + YST, but was unchanged with YST. The number of protozoa was unchanged, and that of cellulolytic bacteria increased (P < 0.05) in all cases. Total gas production increased (P < 0.05) in all cases. Methane decreased, hydrogen was unchanged by YST and both gases were unchanged by CB and CB + YST. The in vitro disappearance of DM and neutral detergent fiber increased (P < 0.05) by 11.2% and 8.9%, 9% and 8.5%, and 12.1% and 10.2% in the case of CB, YST and CB + YST, respectively. Therefore, the dietary supplementation of CB and/or YST may improve ruminal fermentation and digestibility. 相似文献
109.
Kimie NIIMI Ayaka OGUCHI Kenji NISHIO Yasushi OKANO Eiki TAKAHASHI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(3):345-348
The following is a report on a congenital vaginal malformation, imperforate vagina, in
the common marmoset (Callithrix jacchus). This anomaly was observed for
the first time in an adult female in our research colony. There was no uterine and vaginal
aplasia or atresia in her grossly normal genital tract. The plasma progesterone
concentration suggested that the ovarian cycle had ceased. However, this may not be
related to a functional anomaly, but rather to suppressed ovulation resulting from
subordination to cagemates considering the various stages of follicular development
observed. 相似文献
110.
Nozomi TAKAHASHI Eito YAMAGUCHI Yukiko KAWABATA Tomohiro KONO 《The Journal of reproduction and development》2015,61(1):7-12
The distal region of mouse chromosome 12 harbors the Dlk1–Dio3 domain, is essential for normal development and encodes maternally expressed noncoding RNAs (ncRNAs), including Gtl2 as well as paternally expressed proteins.Gtl2 works as a tumor suppressor in several types of human cancer cell lines; however, whether this reflects its function in vivo is unknown. Deleting Gtl2 from the maternal allele (Gtl2(–/+)) results in loss of expression of Gtl2 and decreased expression of downstream ncRNAs, including many miRNAs. To determine the role of ncRNAs in tumorigenesis, we induced teratomas by engrafting E6.5 embryos (wildtype or Gtl2(–/+)) under the kidney capsule of scid mice. Some teratomas derived from the Gtl2(–/+) embryos exhibited hypertrophic growth, suggesting that
ncRNAs, including Gtl2, may act as tumor suppressors in vivo. Microarray analysis of miRNAs expressed by Gtl2(–/+) teratomas revealed decreased expression of 28 miRNAs encoded by the Dlk1–Dio3 domain, low expression of embryonic stem cell-specific miRNAs and dysregulation of miRNAs involved in tumorigenesis. This study suggests that downregulation of ncRNAs in the Dlk1-Dio3 domain leads to enhanced teratoma growth and repression of stem cell markers. 相似文献