全文获取类型
收费全文 | 761篇 |
免费 | 42篇 |
国内免费 | 4篇 |
专业分类
林业 | 34篇 |
农学 | 23篇 |
基础科学 | 1篇 |
207篇 | |
综合类 | 80篇 |
农作物 | 123篇 |
水产渔业 | 58篇 |
畜牧兽医 | 218篇 |
园艺 | 13篇 |
植物保护 | 50篇 |
出版年
2023年 | 2篇 |
2022年 | 18篇 |
2021年 | 24篇 |
2020年 | 16篇 |
2019年 | 25篇 |
2018年 | 18篇 |
2017年 | 17篇 |
2016年 | 27篇 |
2015年 | 32篇 |
2014年 | 26篇 |
2013年 | 46篇 |
2012年 | 58篇 |
2011年 | 73篇 |
2010年 | 26篇 |
2009年 | 14篇 |
2008年 | 42篇 |
2007年 | 40篇 |
2006年 | 40篇 |
2005年 | 32篇 |
2004年 | 31篇 |
2003年 | 30篇 |
2002年 | 25篇 |
2001年 | 23篇 |
2000年 | 22篇 |
1999年 | 14篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 11篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1972年 | 2篇 |
1969年 | 4篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1965年 | 2篇 |
1964年 | 3篇 |
1963年 | 1篇 |
排序方式: 共有807条查询结果,搜索用时 31 毫秒
801.
Lunasin and BBI (Bowman Birk protease inhibitor) are bioactive soy peptides that have been shown to be effective suppressors of carcinogenesis in in vitro and in vivo model systems. Since they are subject to digestion in the gastrointestinal tract, we investigated here the stabilities of lunasin and BBI to digestion in vitro by simulated intestinal fluid (SIF) and simulated gastric fluid (SGF). Samples containing lunasin and BBI of varying purities were subjected to in vitro digestion by SIF and SGF at different times and analyzed by Western blot. While the pure BBI reaction is stable after SIF and SGF digestions, the purified lunasin from soybean and synthetic lunasin are easily digested after 2 min in both in vitro digestions. In contrast, lunasin from soy protein containing BBI is comparatively stable after SIF and SGF digestions. Both lunasin and BBI are able to internalize into the cell and localize in the nucleus even after digestion, suggesting that some of the peptides are intact and bioactive. These data suggest that BBI plays a role in protecting lunasin from digestion when soy protein is consumed orally. The role of other soy protease inhibitors such as Kunitz Trypsin Inhibitor (KTI) cannot be excluded from these experiments. 相似文献
802.
The gene (lat) encoding L-lysine epsilon-aminotransferase (LAT) in Streptomyces clavuligerus was cloned and expressed in Escherichia coli. Nucleotide sequence analysis of lat predicted a single open reading frame (ORF) of 1371 bp, encoding a polypeptide of 457 amino acids with calculated molecular mass of 49.89 kDa. S. clavuligerus LAT was grouped into aminotransferase subfamily II of alpha family on the basis of sequence homology. A model system composed of the recombinant LAT in phosphate buffer was set up to study the biosynthesis of 2-acetyltetrahydropyridine. Lysine was found to be transformed to 1-piperideine-6-carboxylic acid. 2-Acetyltetrahydropyridine was characterized from the mixture of 1-piperideine-6-carboxylic acid and methylglyoxal. For the first time, we demonstrated that the L-lysine epsilon-aminotransferase is responsible for the formation of 1-piperideine-6-carboxylic acid, which may react with methylglyoxal to generate the acylated N-heterocyclic odorant 2-acetyltetrahydropyridine. 相似文献
803.
Different central manifestations in response to electroacupuncture at analgesic and nonanalgesic acupoints in rats: a manganese-enhanced functional magnetic resonance imaging study 总被引:6,自引:0,他引:6
下载免费PDF全文
![点击此处可从《Canadian journal of veterinary research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jen-Hwey Chiu Mao-Shu Chung Hui-Cheng Cheng Tzu-Cheng Yeh Jen-Chuen Hsieh Chung-Yen Chang Wan-Yo Kuo Henrich Cheng Low-Tone Ho 《Canadian journal of veterinary research》2003,67(2):94-101
Acupuncture analgesia is an important issue in veterinary medicine. This study was designed to elucidate central modulation effects in response to electroacupuncture (EA) at different acupoints. Manganese-enhanced functional magnetic resonance imaging was performed in Sprague-Dawley rats after sham acupuncture, sham EA, or true EA at somatic acupoints. The acupoints were divided into 3 groups: group 1, analgesic acupoints commonly used for pain relief, such as Hegu (LI 4); group 2, nonanalgesic acupoints rarely used for analgesic effect, such as Neiguan (PC 6); and group 3, acupoints occasionally used for analgesia, such as Zusanli (ST 36). Image acquisition was performed on a 1.5-T superconductive clinical scanner with a circular polarized extremity coil. The results showed that there was no neural activation caused by EA at a true acupoint with shallow needling and no electric current (sham acupuncture). When EA at a true acupoint was applied with true needling but no electric current (sham EA), there was only a slight increase in brain activity at the hypothalamus; when EA was applied at a true acupoint with true needling and an electric current (true EA), the primary response at the hypothalamus was enhanced. Also, there was a tendency for the early activation of pain-modulation areas to be prominent after EA at analgesic acupoints as compared with nonanalgesic acupoints. In conclusion, understanding the linkage between peripheral acupoint stimulation and central neural pathways provides not only an evidence-based approach for veterinary acupuncture but also a useful guide for clinical applications of acupuncture. 相似文献
804.
Seon Kyeong Park Jin Yong Kang Jong Min Kim Min Ji Kim Hyo Lim Lee Jong Hyun Moon Hye Rin Jeong Hyun-Jin Kim Min-Yu Chung Ho Jin Heo 《Marine drugs》2022,20(7)
To evaluate the biological effects of Porphyra tenera (P. tenera), we tried to confirm the possibility that the intake of P. tenera could modulate cognitive and intestinal functions in PM2.5-induced cognitive decline mice. P. tenera attenuated PM2.5-induced learning and memory impairment through antioxidant and anti-inflammatory effects by regulating the mitochondrial function and TLR-initiated NF-κB signaling. In addition, P. tenera effectively alleviated Aβ production/tau phosphorylation by inhibiting the JNK phosphorylation. Also, the bioactive constituents of P. tenera determined the sulfated galactan, mycosporine-like amino acids (MAAs), and chlorophyll derivatives. Moreover, the bioactive compounds of P. tenera by gut fermentation protected against gut dysbiosis and intestinal tight junction damage with a decrease in inflammatory response and short-chain fatty acid production. Based on these results, our findings suggest that P. tenera with sulfated galactan and MAAs is a potential material for cognitive function improvement. 相似文献
805.
Khalid A. Hussein Mohamed A. A. Abdel-Rahman Ahmed Y. Abdel-Mallek Saad S. El-Maraghy Jin Ho Joo 《Phytoparasitica》2012,40(2):117-126
The greater wax moth Galleria mellonella L. (Lepidoptera: Pyralidae) is occasionally found in beehives and is a major pest of stored wax. Entomopathogenic fungi have
recently received attention as possible biocontrol elements for certain insect pests. In this study, 90 isolates of Beauveria bassiana and 15 isolates of Metarhizium anisopliae were screened for proteases and lipases production. The results showed significant variations in the enzymatic action between
the isolates. In the bioassay, the selected isolates evinced high virulence against the 4th instar of the G. mellonella larvae. The isolates BbaAUMC3076, BbaAUMC3263 and ManAUMC3085 realized 100% mortality at concentrations of 5.5 × 106 conidia ml−1, 5.86 × 105 conidia ml−1, and 4.8 × 106 conidia ml−1, respectively. Strong enzymatic activities in vitro did not necessarily indicate high virulence against the tested insect pest. The cuticle of the infected larvae became dark
and black-spotted, indicating direct attack of fungus on the defense system of the insects. The LC50 values were 1.43 × 103, 1.04 × 105 and 5.06 × 104 for Bba3263AUMC, Bba3076AUMC and Man3085AUMC, respectively, and their slopes were determined by computerized probit analysis
program as 0.738 ± 0.008, 0.635 ± 0.007 and 1.120 ± 0.024, respectively. 相似文献
806.
Jinsheng Cui Eunji Kim Dong Hyun Moon Tae Ho Kim Ilnam Kang Yeonjung Lim Daniel Shin Sunghoon Hwang Young Eun Du Myoung Chong Song Munhyung Bae Jang-Cheon Cho Jichan Jang Sang Kook Lee Yeo Joon Yoon Dong-Chan Oh 《Marine drugs》2022,20(6)
Two new lipo-decapeptides, namely taeanamides A and B (1 and 2), were discovered from the Gram-positive bacterium Streptomyces sp. AMD43, which was isolated from a mudflat sample from Anmyeondo, Korea. The exact molecular masses of 1 and 2 were revealed by high-resolution mass spectrometry, and the planar structures of 1 and 2 were elucidated using NMR spectroscopy. The absolute configurations of 1 and 2 were determined using a combined analysis of 1H-1H coupling constants and ROESY correlations, the advanced Marfey’s method, and bioinformatics. The putative nonribosomal peptide synthetase pathway for the taeanamides was identified by analyzing the full genome sequence data of Streptomyces sp. AMD43. We also found that taeanamide A exhibited mild anti-tuberculosis bioactivity, whereas taeanamide B showed significant bioactivity against several cancer cell lines. 相似文献
807.
Mertens Arne Bawin Yves Vanden Abeele Samuel Kallow Simon Swennen Rony Vu Dang Toan Vu Tuong Dang Minh Ho Thi Panis Bart Vandelook Filip Janssens Steven B. 《Genetic Resources and Crop Evolution》2022,69(7):2515-2534
Genetic Resources and Crop Evolution - Collection and storage of crop wild relative (CWR) germplasm is crucial for preserving species genetic diversity and crop improvement. Nevertheless, much of... 相似文献