全文获取类型
收费全文 | 209篇 |
免费 | 10篇 |
专业分类
林业 | 13篇 |
农学 | 18篇 |
43篇 | |
综合类 | 11篇 |
农作物 | 7篇 |
水产渔业 | 33篇 |
畜牧兽医 | 70篇 |
园艺 | 3篇 |
植物保护 | 21篇 |
出版年
2022年 | 1篇 |
2021年 | 6篇 |
2020年 | 1篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 12篇 |
2013年 | 17篇 |
2012年 | 10篇 |
2011年 | 10篇 |
2010年 | 9篇 |
2009年 | 6篇 |
2008年 | 13篇 |
2007年 | 12篇 |
2006年 | 12篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 12篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有219条查询结果,搜索用时 500 毫秒
111.
Sawai Y Moon JH Sakata K Watanabe N 《Journal of agricultural and food chemistry》2005,53(9):3598-3604
Tea (Camellia sinensis) leaves contain various antioxidants such as ascorbic acid (1) and polyphenols. This study tries to clarify the molecular mechanisms underlying the antioxidative and radical-scavenging activities of these antioxidants, and the reactivities of each antioxidant have been compared against that of the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH, 2) using nuclear magnetic resonance (NMR) analysis. Catechol (3) and (+)-taxifolin (4) were oxidized to o-quinone by 2. However, ethyl protocatechuate (5) and quercetin (6) were not oxidized to o-quinone, even though they possess a catechol structure. The radical-scavenging ability of o-dihydroxyl phenolic compounds with a conjugated olefinic double bond (e.g., 6) was superior to that of compounds without this bond (e.g., 4), whereas the ability of o-dihydroxyl phenolic compounds possessing a conjugated carbonyl bond (5) was inferior to that of compounds lacking this bond (3). Vicinal trihydroxyl phenolic compounds with a conjugated olefinic double bond [e.g., myricetin (7)] had an inferior scavenging ability as compared with compounds lacking this bond [e.g., pyrogallol (8)], but 7 was a better scavenger than compounds with a conjugated carbonyl double bond [e.g., ethyl gallate (9)]. In addition, vicinal trihydroxyl phenolic compounds (e.g., 9) were superior to o-dihydroxyl phenolic compounds (e.g., 6). Finally, 1 scavenged radicals more quickly than 8. 相似文献
112.
Katayama K Tomatsu M Kawahara S Yamauchi K Fuchu H Kodama Y Kawamura Y Muguruma M 《Journal of agricultural and food chemistry》2004,52(4):771-775
A novel angiotensin I-converting enzyme (ACE) inhibitory peptide (RMLGQTPTK; 9mer) from porcine skeletal troponin C was investigated for its inhibitory profile. This peptide was noncompetitive and as hydrophobic as the known ACE inhibitory peptides. Aminopeptidase M quickly hydrolyzed 9mer, resulting in production of MLGQTPTK and LGQTPTK with inhibitory activities similar to those of 9mer. The main hydrolysis product of 9mer with carboxypeptidase A and B was RMLGQTPT showing very weak activity. Most products derived from 9mer hydrolysis by ACE, aminopeptidase, or carboxypeptidase showed weak but definite ACE inhibitory activities. Thus, 9mer was estimated to be a wholly efficient inhibitor with these fragment peptides. 相似文献
113.
ABSTRACT: Sequence variability of the control region of mitochondrial DNA in five Sebastes species ( S. thompsoni , S. joyneri , S. inermis , S. schlegeli and S. owstoni ) was investigated. Of 324 nucleotide sites in the control region of S. thompsoni , 56 sites (17.3%) varied, and all 20 individuals had different haplotypes. The other four species had between five and 17 sites (1.5–5.9%), which was fewer than that observed in S. thompsoni . The nucleotide diversity of S. thompsoni was highest (3.45%) among the five species, and that of S. schlegeli was the lowest (0.19%). The results demonstrated that sequence variability exists in the control region of the five Sebastes fishes investigated, and that sequence data in the control region may be suitable for stock structure analysis. Also, the extent of genetic variablitiy in the control region differed among these species. In particular, the mitochondrial DNA control region in S. thompsoni was characterized by high sequence variability, which may indicate a large effective population size. 相似文献
114.
Agustinus P Harahap Akihiro Takemura Shigeo Nakamura MD Saydur Rahman Kazunori Takano 《Fisheries Science》2001,67(5):888-893
ABSTRACT: This study clarifies the annual reproductive cycle and the lunar-synchronized spawning of the spiny rabbitfish ( Siganus spinus ) that inhabit the Okinawan waters. Annual and weekly changes in the gonadosomatic index (GSI) and the histological features of the ovaries were checked. Gonadosomatic index was high during the months of May to July, and yolk-laden oocytes were observed in the ovaries from March to July. Some of the ovaries collected during June and July contained oocytes at maturation stage or ovulatory follicles. These results suggest that the spiny rabbitfish undergo active vitellogenesis and spawning from May to July. During the reproductive season (May to July), collection of fish according to the lunar phase revealed that a high GSI occurred around the time of the new moon. Cyclic oocyte development with peaks around the time of the same moon phase was also observed, suggesting that, in Okinawan waters, this species is a lunar-synchronized spawner and spawns three times. 相似文献
115.
Jinu Eo Shuhei Takemoto Kazunori Otobe 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):231-237
We investigated if rates of propagation and migration were related with the level of virulence in the pinewood nematode Bursaphelenchus xylophilus using 17 offspring lines from the F2 crosses between virulent and avirulent isolates. Virulence was tested by inoculating seedlings of Pinus thunbergii with the nematodes. The proportion of dead seedlings ranged from 13.3% to 77.8%, 20 weeks after inoculation. Migration rate
of the nematodes was estimated by measuring their migration distance per unit time in an artificial substrate that imitated
pathways in pine trees. Migration rate varied from 0.85 to 3.53 mm min−1. Propagation rate was determined based on population growth on the fungus Botrytis cinerea, and it ranged between 103.88 and 104.99 per 12 days. Statistical analyses revealed that virulence was not correlated with migration rate, but was negatively correlated
with propagation rate on Botrytis cinerea, suggesting that the nematodes paid some cost for virulence. Also, there was no relationship between rates of migration and
propagation. Cluster analysis showed that the biological parameters varied between crossbred lines, with no kinship bias,
suggesting the absence of sex-linked inheritance in virulence and rates of propagation and migration. 相似文献
116.
Dongyan Liu Chika Suekuni Kazunori Akita Toyoaki Ito Masanori Saito Takeshi Watanabe 《Soil Science and Plant Nutrition》2013,59(5):553-561
Paddy field is a major emission source of methane. Methane is the terminal product of anaerobic decomposition of organic matter and generated by methanogenic archaea under flooded conditions in paddy fields. This study aimed to reveal the effect of winter flooding on methanogenic archaeal community structure in paddy fields of Andosols under organic farming. Soil samples were collected from experimental paddy fields in the Field Science Center, Tohoku University, for two years. They were under flooding conditions during winter with organic farming, under non-flooding conditions during winter with organic farming and under non-flooding conditions during winter with conventional farming (non-organic farming). Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis of methanogenic archaeal 16S rRNA gene revealed that the DGGE patterns were nearly the same irrespective of the treatment and sampling times. Twenty-three bands were observed from each treatment and 4, 13 and 6 sequences were closely related to Methanomicrobiales, Methanosarcinales and Methanocellales, respectively. Real-time quantitative PCR analysis indicated that the abundance of methanogenic archaeal 16S rRNA gene and mcrA gene, encoding α subunit of methyl-coenzyme M reductase, was not significantly different among the paddy fields. This study first revealed a methanogenic archaeal community in an Andosol paddy field and showed that the community was not affected by winter flooding under organic farming. 相似文献
117.
118.
Toshiho NISHITA Ryou ANEZAKI Kazunori MATSUNAGA Kensuke ORITO Tamae KASUYA Hideyo SAKANOUE Akiko MATSUNAGA Kazuyoshi ARISHIMA 《Journal of Equine Science》2013,24(4):57-62
Although endoscopy is the definitive diagnostic method for the detection of colonic
ulcers, the equipment required for performing the test is costly and difficult to use.
Therefore, a simple cost-effective and reliable screening test for intestinal tract
bleeding is needed. To this end, we measured carbonic anhydrase isozymes (CA-I and CA-II)
originating from erythrocytes by ELISA in order to determine if they could be used as
markers of occult blood in feces. For fecal extract preparation, 2 g of feces were mixed
with 4 ml of 0.01 M Tris-HCl (pH 8.0) containing 0.01% thimerosal. The concentrations of
CA-I and CA-II in the fecal samples of 13 clinically normal racehorses were found to be
30.0 ± 10.0 and 34.0 ± 13.0 ng/ml, respectively. Increased concentrations of CA-I were
detected in the fecal samples of 5 horses after blood administration; however, no increase
was observed in CA-II. The concentrations of CA-I and CA-II in the fecal samples of 88
racehorses with clinical signs of equine gastric ulcer syndrome (EGUS) were 115.3 ± 79.0
and 41.0 ± 42.0 ng/ml, respectively. Thus, our results indicate that CA isozymes can be
useful as markers of occult blood in the fecal samples of horses with intestinal tract
bleeding. 相似文献
119.
Kuwata K Shibutani M Kemmochi Y Taniai E Morita R Ogawa B Mitsumori K 《Journal of toxicologic pathology》2010,23(3):151-155
In this report, we describe a case of neuroendocrine carcinoma of undetermined origin in a dog. Necropsy revealed scattered small neoplastic nodules in the bilateral lungs and a small nodule in the parapancreatic lymph node. Histopathologically, both pulmonary and lymph nodal nodules showed a similar histologic pattern, with neoplastic cells being arranged in diffusely proliferating sheet-like cellular nests separated by variable amounts of fibrous septa, sometimes forming rosettes and duct-like structures. Scattered small necrotic foci and invasion to fibrous septa were typically observed. Neoplastic cells showed round to oval-shaped nuclei with prominent nucleoli and abundant eosinophilic cytoplasm that were positive for Grimelius' silver impregnation staining and immunostaining with cytokeratin, synaptophysin, vasoactive intestinal peptide and chromogranin A, indicative of the development of a neuroendocrine carcinoma. However, judging from the distribution of tumors lacking the portion suggestive of the primary site in any organ examined, as well as no further indication of differentiation potential of neoplastic cells, this tumor has so far been diagnosed as neuroendocrine carcinoma of undetermined origin. 相似文献
120.
Hanako Shimura Yuki Kogure Kazunori Goto Chikara Masuta 《Journal of General Plant Pathology》2008,74(4):326-330
RNA silencing is a sequence-specific defense mechanism against viruses. As a counterdefense, viruses evolved silencing suppressors
to interfere with host silencing. In analyses using protoplasts prepared from cultured cells (BY-2) and mesophyll cells of
Nicotiana tabacum and N. benthamiana, viral suppressors differentially functioned in different cell types. This phenomenon has not been discussed in earlier papers
on protoplast systems and RNA silencing. In investigations of the cellular activities of viral suppressors and their role
in the RNA-silencing pathway, assays with host protoplasts offer many advantages and can complement other in planta assays
such as Agrobacterium-mediated transient expression. 相似文献