全文获取类型
收费全文 | 223篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
林业 | 30篇 |
农学 | 7篇 |
基础科学 | 4篇 |
37篇 | |
综合类 | 9篇 |
农作物 | 9篇 |
水产渔业 | 37篇 |
畜牧兽医 | 77篇 |
园艺 | 4篇 |
植物保护 | 12篇 |
出版年
2021年 | 1篇 |
2020年 | 8篇 |
2019年 | 2篇 |
2016年 | 5篇 |
2014年 | 6篇 |
2013年 | 24篇 |
2012年 | 10篇 |
2011年 | 14篇 |
2010年 | 6篇 |
2009年 | 10篇 |
2008年 | 20篇 |
2007年 | 18篇 |
2006年 | 20篇 |
2005年 | 17篇 |
2004年 | 16篇 |
2003年 | 14篇 |
2002年 | 8篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1991年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有226条查询结果,搜索用时 46 毫秒
31.
Mori E Fukuda H Imajoh-Ohmi S Mori T Takasaki S 《The Journal of reproduction and development》2012,58(1):117-125
Although the importance of carbohydrate recognition by sperm during egg zona pellucida binding has been widely reported, the sperm molecular species that recognize the carbohydrates are poorly characterized. Our previous cytochemical study indicated that two kinds of carbohydrate-binding proteins are expressed on porcine sperm heads-one recognizes N-acetyllactosamine (Galβ1-4GlcNAc-), and the other recognizes the Lewis X structure (Galβ1-4(Fucα1-3)GlcNAc-). For this report, we used proteomic techniques to characterize the sperm proteins that bind N-acetyllactosamine. Porcine sperm plasma membrane was solubilized with a detergent solution and subjected to sequential chromatography with dextran sulfate agarose, affinity, and hydroxyapatite, and the binding activities in the eluates were monitored by a solid-phase binding assay. The tryptic peptides of two proteins most likely associated with the binding activities were subjected to tandem mass spectrometry sequencing. A subsequent database search identified one of the two proteins as predicted disintegrin and metalloprotease domain-containing protein 20-like (XP_003128672). The other protein was identified as disintegrin and metalloprotease domain-containing protein 5 (AB613817) by database searches for homologous amino acid sequences, cDNA cloning, nucleotide sequencing and nucleotide database searches. Furthermore, two-dimensional blue native/SDS-PAGE demonstrated that they formed a variety of non-covalent complexes. Therefore, these ADAM complexes probably are responsible for the N-acetyllactosamine-binding activity. An affinity-purified fraction containing these ADAM complexes showed zona pellucida-binding activity, though the activity was relatively weak, and the presence of another zona pellucida-binding protein that probably works in concert with these ADAM complexes was suggested. Immunofluorescence testing suggested that ADAM20-like was localized on the anterior part of the sperm plasma membrane. 相似文献
32.
Glycosylated Porphyra-334 and Palythine-Threonine from the Terrestrial Cyanobacterium Nostoc commune
Ehsan Nazifi Naoki Wada Minami Yamaba Tomoya Asano Takumi Nishiuchi Seiichi Matsugo Toshio Sakamoto 《Marine drugs》2013,11(9):3124-3154
Mycosporine-like amino acids (MAAs) are water-soluble UV-absorbing pigments, and structurally different MAAs have been identified in eukaryotic algae and cyanobacteria. In this study novel glycosylated MAAs were found in the terrestrial cyanobacterium Nostoc commune (N. commune). An MAA with an absorption maximum at 334 nm was identified as a hexose-bound porphyra-334 derivative with a molecular mass of 508 Da. Another MAA with an absorption maximum at 322 nm was identified as a two hexose-bound palythine-threonine derivative with a molecular mass of 612 Da. These purified MAAs have radical scavenging activities in vitro, which suggests multifunctional roles as sunscreens and antioxidants. The 612-Da MAA accounted for approximately 60% of the total MAAs and contributed approximately 20% of the total radical scavenging activities in a water extract, indicating that it is the major water-soluble UV-protectant and radical scavenger component. The hexose-bound porphyra-334 derivative and the glycosylated palythine-threonine derivatives were found in a specific genotype of N. commune, suggesting that glycosylated MAA patterns could be a chemotaxonomic marker for the characterization of the morphologically indistinguishable N. commune. The glycosylation of porphyra-334 and palythine-threonine in N. commune suggests a unique adaptation for terrestrial environments that are drastically fluctuating in comparison to stable aquatic environments. 相似文献
33.
为茶园生态控草提供理论依据,以茶单作茶园为对照,采用5点取样法研究茶-芋间作茶园夏季杂草的种类/群落结构及其防治效果。结果表明:2类茶园中主要杂草有20科37种,其中,茶-芋间作茶园有17科24种,杂草科的数目较对照(16科30种)多,但杂草种类数目较对照少。茶-芋间作同时期杂草田间密度和物种丰富度较对照显著降低,最高株防效达92%,夏季6-8月平均株防效为73. 6%;茶-芋间作可改变茶园杂草群落结构,显著降低优势杂草的危害程度。单作茶园的优势杂草为尼泊尔蓼、丛枝蓼、薄叶新耳草、野茼蒿和碎米荠,茶-芋间作茶园优势杂草为野茼蒿、薄叶新耳草、蕺菜、宽叶母草和尼泊尔蓼。 相似文献
34.
Morioka K Fukai K Ohashi S Sakamoto K Tsuda T Yoshida K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(7):653-658
At least two biotypes were observed at the 2nd passage stage after the isolation of Foot-and-mouth disease Virus (FMDV) O/JPN/2000 strain. These 2 types of viruses differed from their plaque phenotypes and were distinguishable by using a monoclonal antibody (MAb) 64G8 that was made for the FMDV O/JPN/2000 strain. One of these 2 biotypes formed small plaque (SP) and with immuno staining showed a positive reaction to MAb 64G8, while the other formed clear large plaque (LP) and did not react with MAb 64G8. The amino acid sequences of the capsid coding region (VP1-VP4) of the SP virus (SPV) and the LP virus (LPV) revealed two substitutions on the 133rd amino acid in VP2, and the 56th amino acid in VP3. These amino acid changes of SPV and LPV are Asn to Asp, Arg to His, respectively. The Arg of the 56th amino acid in VP3 that have been known as critical position of cell culture adapted virus. Only LPV showed high pathogenicity in suckling mice, and its LD(50) was calculated to be about 10(2) TCID(50)/0.1 ml. These results showed that the SPV that existed at the 2nd passage stage from isolation was a low virulence virus, which may suggest why the pathogenicity of O/JPN/2000 did not show clear symptoms in infected cattle. 相似文献
35.
Saki Ishimaru Mabrouk Elsabagh Seiichi Saiki Atsushi Haruno Maki Nakamura Hidetada Funo Taketo Obitsu Izuru Shinzato Toshihisa Sugino 《Animal Science Journal》2019,90(8):932-938
Three rumen‐protected lysine (RPL) products (AjiPro®‐L, LysiPEARLTM, and Feedtech Bypass LysineTM: A, B, and C, respectively) were tested for stability in two forage‐based total mixed rations (TMR1, 41.3% dry matter (DM), and TMR2, 49.5% DM) (experiment 1) and for Brix value (experiment 2). In experiment 1, each RPL product (2 g each) and TMR diet (200 g) were mixed and stored in plastic bags at 20°C for 0, 1, 3, 6, 12, 24, and 48 hr. In experiment 2, each RPL product (2 g) was dispensed into ion‐exchanged water (20 ml) and kept at 20°C for 0, 0.5, 1, 3, 6, 12, 24, and 48 hr. At each time point, free lysine (Lys) content and Brix values of extracts were measured, and Lys release (LR, %) was calculated. All RPL products LR% varied with varying diets DM and increased with increasing of time exposed to diets; it was highest in C, followed by B, and then A. Water LR% positively correlated with that from diets and with Brix values of Lys dissociated in water. Our results indicated that Lys dissociation from RPL products is affected by diet DM content. Brix value may be used as a potential marker for RPL protection efficacy. 相似文献
36.
Kazutaka Kanai Mariko Hino Yasutomo Hori Ruriko Nakao Fumio Hoshi Naoyuki Itoh Seiichi Higuchi 《Journal of veterinary science (Suw?n-si, Korea)》2008,9(4):421-423
The purpose of this study was to determine if salivary chromogranin a secretion in dogs exhibits a circadian rhythm. Saliva sampling was performed during three different sessions occurring in three nonconsecutive 24-h periods. Sixteen healthy adult beagle dogs (8 males and 8 females) were moved to a sampling room and housed individually in cages. Saliva samples were obtained every 4 h from 12:00 p.m. to 12:00 p.m. the following day. In the interest of habituation, saliva was obtained hourly from each dog 3 h before the experiment was started. Salivary chromogranin A concentrations were measured using an enzyme-linked immunosorbent assay. No circadian rhythm was detected for salivary chromogranin A secretion, and no differences in salivary chromogranin A concentrations measured every 4 h were demonstrated during the 24-h cycle in dogs. 相似文献
37.
Tomonari Kotani Masashi Yokota Hiroshi Fushimi Seiichi Watanabe 《Fisheries Science》2011,77(2):255-261
Survival in larval rearing experiments is difficult to estimate due to accidental losses and periodic sampling. The number
of sampled fish can be a large proportion of the stocked ones, making it difficult to calculate the overall survival rate
and mortality coefficient as this is based on the initial number. Here, a new method of calculating survival is proposed using
the mortality coefficient. When the initial stocking density and sampled and final numbers are known, and assuming that mortality
coefficient is constant, the final number of fishes can be represented by the formula N
t = e−mt
(N
0 − ΣN
Sne
mdn), where t is rearing period (days), N
0 indicates initial number, N
t indicates the survival number at t days of rearing, m is the natural mortality coefficient, N
Sn is the sampled number in the nth sampling, and dn is the rearing period until removal of the nth sample. The provisional mortality coefficient is calculated from initial and final stocking numbers. Then values for the
natural mortality coefficient are substituted into the formula with successive approximation. The coefficient, which most
closely approximates the actual survival, is determined as the best fit natural mortality coefficient. Examples of larval
experiments are provided to demonstrate the method and show that survival is often underestimated using traditional methods. 相似文献
38.
Mohamed Salah Mahjoub Seiichi Takeda Toshifumi Hayashi Daisuke Shiode Takafumi Arimoto Tadashi Tokai 《Fisheries Science》2011,77(2):169-181
Codend selectivity for the jack mackerel Trachurus japonicus and the whitefin jack Kaiwarinus equula were evaluated based on data from trouser trawl experiments carried out in the East China Sea, using a test codend of 60 mm diamond mesh and a control codend made of minnow net with a square mesh of 9 mm bar length. Between-haul variations in parameters and the mean selection curves were tested with the catch data in the SELECT approach, and then the model of between-haul variation in the split parameter with the mean selection curve was chosen as the best fit using Akaike’s information criterion model selection. The 50% retention lengths and the selection ranges were 11.4 and 3.36 cm for jack mackerel and 8.83 and 0.93 cm for whitefin jack, respectively. The selection curve for whitefin jack was sharp, whereas that for jack mackerel was relatively wide. As the estimated split parameters indicated, about 80% of the whitefin jack entered the control codend, but 85 and 90% of the jack mackerel entered the control codend in the second and third hauls, respectively. The inequality in the split parameter is discussed from the viewpoint of the animal’s swimming behavior and water movement based on underwater video observations. 相似文献
39.
Md. Masud Karim Nazmoon Naher Tonu Mohammad Shakhawat Hossain Taketo Funaki M. Bahadur Meah Delwar M. Hossain M. Asad ud-doullah Eigo Fukai Keiichi Okazaki 《Euphytica》2016,208(3):535-544
Low erucic acid (LEA) rapeseed, which has accumulated mutant fatty acid elongase genes at the BnFAE1.1 and BnFAE1.2 loci of the A- and C-genome, respectively, is an important oilseed crop. Short growing turnip rape (B. rapa) is also important as a catch crop in the continuous cropping of rice in Asia but there is no LEA B. rapa cultivar for cultivation in South Asia. In order to develop LEA turnip rape cultivars, high erucic acid turnip rape cultivars were interspecifically crossed as recurrent parents to a canola quality rapeseed. In the meantime, we monitored incorporation of the mutant bnfae1.1 (e1) gene into A-genome of turnip rape, using a dCAPS primer pair, which can amplify PCR fragment only for the mutant e1 gene from A-genome. The early backcross progenies showed poor seed set, but which was improved in advanced progenies. Finally, homozygous e1e1 genotypes were established in the selfed progenies of BC2–BC3, and their LEA content was confirmed by gas-chromatography analysis. Our results and promising lines will contribute to LEA-trait selection in turnip rape and rapeseed breeding. 相似文献
40.
Seiichi Furuya Mai Mochizuki Seiya Saito Hironori Kobayashi Tsutomu Takayanagi Shunji Suzuki 《Pest management science》2010,66(11):1268-1272
BACKGROUND: The increasing occurrence of QoI fungicide resistance in Plasmopara viticola (Berk. & MA Curtis) Berl. & DeToni populations is becoming a serious problem in the control of grapevine downy mildew. In Japan, the existence of QoI‐fungicide‐resistant P. viticola was reported in 2009. RESULTS: The QoI fungicide resistance in P. viticola samples collected from vineyards in Japan in 2008 and 2009 was monitored. Resistant P. viticola were detected in the regions where QoI fungicides have been introduced in accordance with the pest management programme, whereas in Hokkaido vineyards, where QoI fungicides have not yet been introduced, QoI‐fungicide‐resistant P. viticola were not found. CONCLUSION: Japan comprises thousands of islands and is physically isolated from other countries by the sea. Monitoring the emergence, incidence and distribution of QoI fungicide resistance in P. viticola populations in Japan is necessary to improve pest management strategies for downy mildew disease in Japanese vineyards. Copyright © 2010 Society of Chemical Industry 相似文献