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201.
Delgado M. VALDEZ JR . Ryoma TSUCHIYA Shinsuke SEKI Naoya SAIDA Saori NIIMI Chihiro KOSHIMOTO Kazutsugu MATSUKAWA Magosaburo KASAI Keisuke EDASHIGE 《The Journal of reproduction and development》2013,59(2):205-213
Fish oocytes have not been cryopreserved successfully, probably because it is difficult
to prevent intracellular ice from forming. Previously, we have shown in medaka that
immature oocytes are more suitable for cryopreservation than mature oocytes or embryos, in
terms of permeability. We have also shown in immature medaka oocytes that the exogenous
expression of aquaporin 3 (AQP3), a water/cryoprotectant channel, promotes the movement of
water and cryoprotectants through the plasma membrane. In the present study, we attempted
to cryopreserve immature medaka oocytes expressing AQP3. We first examined effects of
hypertonic stress and the chemical toxicity of cryoprotectants on the survival of the
AQP3-expressing oocytes. Exposure to hypertonic solutions containing sucrose decreased the
survival of oocytes, but the expression of AQP3 did not affect sensitivity to hypertonic
stress. Also, AQP3 expression did not markedly increase sensitivity to the toxicity of
cryoprotectants. Of the four cryoprotectants tested, propylene glycol was the least toxic.
Using a propylene glycol-based solution, therefore, we tried to cryopreserve immature
oocytes by vitrification. During cooling with liquid nitrogen, all intact oocytes became
opaque, but many AQP3-expressing oocytes remained transparent. This indicates that the
expression of AQP3 is effective in preventing intracellular ice from forming during
cooling. During warming, however, all the AQP3-expressing oocytes became opaque,
indicating that intracellular ice formed. Therefore, the dehydration and permeation by
propylene glycol were still insufficient. Further studies are necessary to realize the
cryopreservation of fish oocytes. 相似文献
202.
203.
Ohnishi H Iwanaga S Kawazoe K Ishizawa K Orino S Tomita S Tsuchiya K Kanematsu Y Harada N Mori K Tsuchihashi T Ishikawa Y Tamaki T 《Journal of agricultural and food chemistry》2008,56(21):10092-10098
This study investigated whether reducing agents such as quercetin and iron(II) facilitate formation of nitric oxide (NO) gas from orally ingested nitrite in an vivo study. When 3 mg/kg Na (15)NO2 was orally administered to rats with or without iron(II) or quercetin, Hb (15)NO, which is indicative of systemic (15)NO, was detected in the blood, with the maximum blood concentration of Hb (15)NO at 15 min after nitrite or nitrite plus quercetin treatment, whereas after administration of nitrite plus iron(II) or nitrite plus iron(II) and quercetin, the time was shortened to 10 min. Interestingly, iron(II), quercetin, or iron(II) plus quercetin did not affect the total amount of Hb (15)NO generated from orally administered Na (15)NO2. However, the systemic nitrite concentration was significantly decreased in the presence of iron(II) or iron(II) plus quercetin. These results may indicate that iron(II) is critical to the generation of NO gas from nitrite, whereas quercetin contributed little under the in vivo experimental conditions. 相似文献
204.
Larval survival,development and growth in the horsehair crab,Erimacrus isenbeckii,cultured under different photoperiod conditions
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Larval sinking causes larval mass mortality during seed production in the horsehair crab, Erimacrus isenbeckii. Under normal light conditions, horsehair crab larvae generally show negative phototactic behaviour and sink in their rearing seawater. It has been proposed that culturing larvae in the dark may prevent larval sinking. Herein, we examined the effect of photoperiods on horsehair crab larval survival and development to facilitate the development of larval rearing techniques that prevent sinking. Newly hatched larvae were reared with Artemia to the first crab stage in 2‐L beakers under five photoperiods: 0L:24D, 6L:18D, 12L:12D, 18L:6D and 24L:0D. Larvae survived and molted to the first crab stage under all tested photoperiod conditions. The survival rate improved with increasing light period, whereas the developmental period for each larval stage decreased with increasing light period. Longer light periods increased the carapace length at the first crab stage. Our results suggest that larvae could be cultured to the first crab stage in large‐scale tanks under constant darkness. However, significantly improved larval performance under longer photoperiodic conditions indicates a need for developing alternative culture techniques to control larval behaviour in the seed production tank. 相似文献
205.
206.
Keisuke Tomioka Toyozo Sato Jouji Moriwaki Yuichi Terasawa Hiroki Koganezawa 《Journal of General Plant Pathology》2012,78(2):133-135
Severe spotting and blighting of leaves were found on bacopa (Sutera cordata), a scrophulariaceous ornamental, in greenhouses in Gunma Prefecture, Japan, from January through February 2007. After we
isolated and identified the causal fungus as Colletotrichum destructivum and inoculated host plants with the isolate to confirm pathogenicity, we named this new disease anthracnose of bacopa. 相似文献
207.
Kozai K Hojo T Takahashi M Acosta TJ Nambo Y Okuda K 《The Journal of reproduction and development》2012,58(4):393-397
Although circulating progesterone (P(4)) levels tend to change with the season, little is known about the seasonal changes of P(4) synthesis-related proteins in the corpus luteum (CL) of mares. To examine these changes, seventy-four ovaries containing a CL were collected from Anglo-Norman mares at a local abattoir in Kumamoto, Japan (~N32°), five times during one year. The stages of the CLs were classified as early, mid and regressed by macroscopic observation of the CL and follicles. The mid CL, which had the highest P(4) concentration, was used to evaluate the seasonal changes in P(4) synthesis. The luteal P(4) concentration and mRNA expression of luteinizing hormone receptor (LHCGR) were lowest during early winter and highest during late winter. The mRNA expressions of steroidogenic acute regulatory protein (StAR), P450 cholesterol side-chain cleavage enzyme (P450scc) and 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (3β-HSD) were lowest during early winter and increased during late winter. These results suggest that P(4) synthesis in the CL is affected by the seasonal changes in the mRNA expressions of P(4) synthesis-related proteins in mares. 相似文献
208.
Symon M. Njinju Hiroaki Samejima Keisuke Katsura Mayumi Kikuta Joseph P. Gweyi-Onyango John M. Kimani 《Plant Production Science》2018,21(2):59-70
Tropical highland conditions in Mwea Kenya, ensure the high radiation and the large day–night temperature differences. Such conditions are generally believed to promote rice growth and yield, but the current grain yield is lower than the expectation. In the current standard N fertilizer practice in Mwea, 75 kg nitrogen (N) ha?1 is applied in three splits at fixed timing. The effects of increases in N fertilizer amount (125, 175, and 225 kg N ha?1) on rice growth and yield were evaluated to test the hypothesis that unachieved high rice grain yield in Mwea is due to insufficient amount of N fertilizer. Two popular lowland varieties in Mwea (Basmati 370 and BW196) and two varieties reported as high yielding in other countries (Takanari and IR72) were used. Shoot dry weight (DW) increased with increases in the amount of N fertilizer applied in three splits at fixed timing, irrespective of variety. It reached approximately 20 t ha?1 under increased N conditions (>75 kg N ha?1) in several cases, indicating that high biomass production could be achieved by increasing N application rate. However, the increased biomass did not increase grain yield, due to decreased grain filling under high N conditions in all varieties. Thus, N amounts above 75 kg ha?1 were ineffective for increasing grain yields in Mwea, where N fertilizer was applied in three splits at fixed timing. Increasing influence of low temperature under high N conditions may be one of the reasons for the decreased grain filling in Mwea. 相似文献
209.
Characterization of canine caspase-3 总被引:1,自引:0,他引:1
Sano J Oguma K Kano R Hasegawa A 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(5):563-567
The canine caspase-3 gene was cloned and sequenced. The canine caspase-3 cDNA clone was 1473 base pairs in length and encoded 277 amino acids. The predicted amino acid sequence showed 88.4%, 88.0%, 85.9%, 65.9% and 60.6% homology with that of human, pig, mouse, chicken and zebra fish caspase-3, respectively. The caspase-3 mRNA was confirmed to express in skin, lymph node, bone marrow, small intestine and lung from a healthy dog by RT-PCR analysis. 相似文献
210.
Yonehara K Suzuki M Yamanouchi K Nishihara M 《The Journal of reproduction and development》2003,49(6):547-552
Estrogen plays an important role in sexual differentiation of the brain in rats during the perinatal period. To elucidate molecular mechanisms underlying sexual differentiation of the brain, in this study we investigated genes differentially expressed between sexes or induced to express by estrogen in neonatal rat hypothalamus using DNA microarray analysis in combination with real-time RT-PCR. It was found that the levels of expression of the genes encoding glutamic acid decarboxylase 65 and coronin 1b were higher in male than female hypothalamus on postnatal day (PN) 5 and those of collagen type 3 alpha1 and thioredoxin reductase 2 genes in female hypothalamus on PN5 were decreased and increased, respectively, by treatment with estradiol on PN2. Then the developmental changes in the expression of these 4 genes were examined from 1 day before the parturition to PN9, and they all showed sexual dimorphic patterns. In addition, dependence of the expression of these genes on either estradiol, testosterone or dihydrotestosterone during the neonatal period was confirmed. These results suggest that these four genes are involved in sexual differentiation of the rat brain, and that androgen per se as well as estrogen may take part in the processes. 相似文献