全文获取类型
收费全文 | 154篇 |
免费 | 31篇 |
国内免费 | 25篇 |
学科分类
农业科学 | 210篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 16篇 |
2016年 | 15篇 |
2015年 | 10篇 |
2014年 | 13篇 |
2013年 | 11篇 |
2012年 | 6篇 |
2011年 | 12篇 |
2010年 | 13篇 |
2009年 | 19篇 |
2008年 | 8篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
排序方式: 共有210条查询结果,搜索用时 0 毫秒
1.
Ting Zhang Faming Yang Xiaoming Qin Xianmei Yang Chaohua Zhang Zhaoyi Wan Haisheng Lin 《Marine drugs》2022,20(7)
Previous studies found that both oral and topical administration of enzymatic digestion products < 3 K Da ultrafiltration fractions of Pinctada martensii mantle (PMPs) had pro-healing effects. Thus, we further purified them by Sephadex-G25 and screened them by cellular assays to obtain Pinctada martensii purified peptides (PMPPs). In this study, we explored the mechanism of PMPPs on wound healing by in vivo, in vitro, and in silico experiments. LC-MS/MS results showed that PMPPs consisted of 33 peptides with molecular weights ranging from 758.43 to 2014.04 Da, and the characteristic peptide was Leu-Asp. The results of cellular assays showed that PMPPs promoted the proliferation of human skin fibroblasts (HSF) (135%) and human immortalized keratinocyte (HaCaT) cells (125%) very significantly at 12.5 μg/mL. The in vivo results showed that PMPPs could achieve scarless healing by inhibiting the inflammatory response, accelerating the epithelialization process, and regulating collagen I/III ratio. The optimal peptide sequence FAFQAEIAQLMS of PMPPs was screened for key protein receptors in wound healing (EGFR1, FGFR1, and MMP-1) with the help of molecular docking technique, which also showed to be the key pro-healing active peptide sequence. Therefore, it may provide a therapeutic strategy with great potential for wound healing. 相似文献
2.
为改善马氏珠母贝 (
3.
Tomoki Hashimoto Katsuya Hyodoh Takuma Hirose Satoshi Nishikawa Toshiya Katano Shin-ichi Nakano 《Aquaculture International》2008,16(4):309-318
In the pearl cultivation farms of the Ehime Prefecture, Japan, mass mortalities of the pearl oyster Pinctada fucata have occurred since 1994. The occurrences of mass mortality roughly coincided with a shift of the dominant phytoplankton
from Skeletonema and Chaetoceros to Chaetoceros and Nitzschia all of which belong to Bacillariophyceae. Hence, we evaluated Nitzschia, together with Chaetoceros and Isocrysis, as food for the oyster. Wet weights, lengths, widths, glycogen contents, and growth rates in terms of wet weight of the
oysters in all the feeding treatments were significantly higher than those in the non-feeding treatment. The highest glycogen
content (2.34%) and growth rate (2.21 g month−1) were found in the Chaetoceros treatment. Growth rate in the Isocrysis treatment (1.63 g month−1) was also high, although glycogen content in this treatment (0.41%) was low. In the Nitzschia treatment, growth rate of the oyster (0.94 g month−1) was the lowest and glycogen content (0.83%) was also low relative to that in the Chaetoceros treatment. Chlorophyll a concentration in fecal pellets was lowest in the Nitzschia treatment (<2.7 μg mg−1), suggesting more complete digestion of Nitzschia by the oyster. Thus, Nitzschia was edible and digestible but not assimilated by P. fucata. We propose the following scenario for the relationship between Nitzschia dominance and mass mortality. When Nitzschia dominates in a culture area, the physiological condition of P. fucata deteriorates due to low assimilation of Nitzschia by the oyster, followed by susceptibility of the oyster to infection by agents lethal to the oyster. 相似文献
4.
胰岛素样生长因子2结合蛋白( IGF2BPs)是一种重要的RNA代谢调控因子,涉及多个不同的生物学过程。本研究鉴定了一个马氏珠母贝IGF2BP1基因,命名为PfIGF2BP1-1,该基因cDNA全长为7348 bp,ORF长 1818 bp,编码605个氨基酸。多序列比对和系统进化分析表明,PfIGF2BP1-1有2个RRM结构域和4个KH结构域,与其他物种来源的IGF2BPs同源。实时荧光定量PCR结果显示,PfIGF2BP1-1 在马氏珠母贝的8个组织中均有表达,在肌肉组织表达最高,其次为足和外套膜组织。利用pET-32a 原核表达载体构建了含有PfIGF2BP1-1成熟多肽区的重组质粒并成功表达蛋白。在IPTG浓度为0.5 mmol/L,37 ℃培养8 h的条件下诱导表达PfIGF2BP1-1蛋白最佳。PfIGF2BP1-1蛋白刺激马氏珠母贝外套膜原代细胞,引起壳基质蛋白基因Accbp、MSI7、Nacrein的表达水平显著上升(p < 0.05),表明PfIGF2BP1-1蛋白可诱导壳矿化相关基因的表达参与马氏珠母贝的生物矿化过程。 相似文献
5.
Variation in clearance and ingestion rates by larvae of the black-lip pearl oyster (Pinctada margaritifera, L.) feeding on various microalgae 总被引:1,自引:0,他引:1
Clearance rate (CR) and ingestion rate (IR) of different sizes (89, 125 and 188 μm shell length) of Pinctada margaritifera larvae were determined when feeding on various microalgae. The microalgae tested were the diatoms, Chaetoceros muelleri and C. simplex, and flagellates, Tahitian Isochrysis aff. galbana, Pavlova lutheri and P. salina at 5 or 10 cells μL–1. Both CR and IR of microalgae tested in this study increased with increasing larval size; but at all larval sizes, diatoms resulted in lower CR and IR. Of the microalgae tested, P. margaritifera larvae showed greatest CR and IR with the two Pavlova spp. Maximum CR for P. salina was 10.5, 21.2 and 29.7 μL h–1 for larvae with shell lengths of 89, 125 and 188 μm, respectively. The highest IR values for P. margaritifera larvae with shell lengths of 89, 125 and 188 μm were 8.7, 81.0 and 165.7 cells·larva–1 h–1, respectively. CR and IR of P. salina were approximately five times higher than those recorded for C. muelleri and C. simplex. 相似文献
6.
Kolliyil S Mohamed Vasanth Kripa Tharammal S Velayudhan Kavintekizhakkathil K Appukuttan 《Aquaculture Research》2006,37(7):725-741
Comparative studies were made on the growth and biometric relationships of the pearl oyster Pinctada fucata (Gould) Tuticorin stock at (Tuticorin (TST) – parent stock) transplanted from the Tuticorin Bay (8.7°N; 78.2°E) in the Gulf of Mannar along the Indian southeast coast to Kollam Bay (8.8°N; 76.5°E) in the Arabian Sea along the Indian southwest coast (Tuticorin stock at Kollam (TSK) – transplanted stock). At the time of transplantation, Kollam Bay did not have a native stock, however, within a year, the transplanted stock spawned and oyster spats were collected from within the farm (Kollam stock (KS) – progeny stock). The growth in dorso‐ventral measurement and total weight in Kollam Bay was 1.4–1.6 times and 3.1 to 6.8 times respectively greater than that observed at Tuticorin. Furthermore, at Kollam Bay, the thickness observed at the end of first year was similar to that obtained at the end of second year in Tuticorin. Both the TSK and KS had significantly higher instantaneous growth rates (IGR) than TST. All the stocks displayed significantly different biometric relationships. The increased growth in Kollam Bay is attributed to the almost double productivity in the Arabian Sea compared with the Bay of Bengal. It is concluded that in the case of P. fucata, the site and its interaction with environment are important determinants of growth and shell dimensions. The present study clearly indicates that the environmental conditions prevailing along the southeast Arabian Sea are congenial for the growth, gametogenesis, spawning and settlement of P. fucata larvae. In spite of strong monsoonal influences in the hydrology of Kollam Bay, the growth and reproduction of P. fucata stocks indicates its relative hardiness and ability to adapt to a changed environment. 相似文献
7.
This paper reports on 5 experiments conducted to assess the effect of cleaning regime and predation on growth and survival
of blacklip pearl oyster (Pinctada margaritifera) juveniles in north Queensland, Australia. P. margaritifera juveniles with a mean (±SE) dorso-ventral shell height (DVH) of 4.5 ± 0.1 mm were placed into plastic mesh trays and cleaned
either every 4 or 8 weeks or left uncleaned for 16 weeks. Cleaning regime had a significant effect on growth and survival
(P < 0.005). Lowest DVH (16.2 ± 1.0) was shown by oysters in uncleaned trays during 16 weeks compared to oysters in cleaned
trays; however, there was no significant difference in DVH between oysters held in trays cleaned every 4 (19.4 ± 1.2) or 8
weeks (21.2 ± 0.8). In contrast lowest survival was shown by oysters held in trays that were cleaned every 4 weeks (30 ± 5%),
but no differences were noted between oysters cleaned every 8 weeks (63 ± 4%) and oysters that were left uncleaned for 16
weeks (75 ± 8%). Predators of P. margaritifera in northern Australia included crabs, stomatopods, flatworms, gastropods and fish. The stomatopod, Gonodactylus falcatus, was the most destructive predator with individuals consuming in excess of 20 juvenile pearl oysters per week. The leather
jacket, Paramonocanthus japonicus, did not kill pearl oysters, but trimmed the margin of oysters shells significantly reducing DVH when compared to control
groups cultured without fish. Removing predators monthly had a significant effect on growth of pearl oysters compared to oysters
in non-inspected trays; however monthly inspection of culture trays did not significantly improve oyster survival.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
This paper presents the first laboratory study investigating larval settlement and metamorphosis of Pinctada maxima in response to both natural and artificial inducers. Natural biofilms induced larval settlement and the inductive effect appears to be closely associated with the bacteria in the biofilm. This result indicates that, in nature, bacteria may play an important role in the settlement of P. maxima larvae. Various pharmacological agents were also tested in this study and the results were generally similar to those found with other marine invertebrates, particularly molluscs. The results show that some pharmacological agents are potent artificial inducers of larval settlement for P. maxima. The findings of this study provide valuable information for understanding the mechanism of the larval settlement of this species, which is useful information for the hatchery industry of this pearl oyster. 相似文献
9.
2007年4月,从马氏珠母贝基础群体选取2、4、32和158个亲本分别繁殖4个子代群体,分别命名为P1、P2、P3和P4。2009年7月,从这4个子代群体随机取样30个个体,利用7对微卫星引物分析其遗传结构。结果表明,7对微卫星引物共检测到22个等位基因,每个座位的等位基因数目为2~4个,平均等位基因数为3个,平均有效等位基因数为2.3193。P1、P2、P3和P4群体平均观测杂合度分别为0.4737、0.5489、0.6767和0.7143;P1、P2、P3和P4群体平均期望杂合度分别为0.4737、0.5489、0.6767和0.7143;P1、P2、P3和P4群体的多态信息含量分别为0.4472、0.4224、0.4726和0.4930。本结果表明4个养殖群体均具有较高的遗传多样性,而且有效亲本数目对子代遗传结构有较大的影响,这为马氏珠母贝的遗传育种提供依据。 相似文献
10.