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21.
Cartilage acidic protein-1B (LOTUS), an endogenous Nogo receptor antagonist for axon tract formation
Sato Y Iketani M Kurihara Y Yamaguchi M Yamashita N Nakamura F Arie Y Kawasaki T Hirata T Abe T Kiyonari H Strittmatter SM Goshima Y Takei K 《Science (New York, N.Y.)》2011,333(6043):769-773
Neural circuitry formation depends on the molecular control of axonal projection during development. By screening with fluorophore-assisted light inactivation in the developing mouse brain, we identified cartilage acidic protein-1B as a key molecule for lateral olfactory tract (LOT) formation and named it LOT usher substance (LOTUS). We further identified Nogo receptor-1 (NgR1) as a LOTUS-binding protein. NgR1 is a receptor of myelin-derived axon growth inhibitors, such as Nogo, which prevent neural regeneration in the adult. LOTUS suppressed Nogo-NgR1 binding and Nogo-induced growth cone collapse. A defasciculated LOT was present in lotus-deficient mice but not in mice lacking both lotus- and ngr1. These findings suggest that endogenous antagonism of NgR1 by LOTUS is crucial for normal LOT formation. 相似文献
22.
Yurimoto H Abe K Abe M Ebihara M Fujimura A Hashiguchi M Hashizume K Ireland TR Itoh S Katayama J Kato C Kawaguchi J Kawasaki N Kitajima F Kobayashi S Meike T Mukai T Nagao K Nakamura T Naraoka H Noguchi T Okazaki R Park C Sakamoto N Seto Y Takei M Tsuchiyama A Uesugi M Wakaki S Yada T Yamamoto K Yoshikawa M Zolensky ME 《Science (New York, N.Y.)》2011,333(6046):1116-1119
Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid. 相似文献
23.
Nakai M Fukui Y Asami S Toyoda-Ono Y Iwashita T Shibata H Mitsunaga T Hashimoto F Kiso Y 《Journal of agricultural and food chemistry》2005,53(11):4593-4598
Fifty-four polyphenols isolated from tea leaves were evaluated for their inhibitory activities against pancreatic lipase, the key enzyme of lipid absorption in the gut. (-)-Epigallocatechin 3-O-gallate (EGCG), which is one of major polyphenols in green tea, showed lipase inhibition with an IC50 of 0.349 microM. Moreover, flavan-3-ol digallate esters, such as (-)-epigallocatechin-3,5-digallate, showed higher activities of inhibition on lipase with an IC50 of 0.098 microM. On the other hand, nonesterified flavan-3-ols, such as (+)-catechin, (-)-epicatechin, (+)-gallocatechin, and (-)-epigallocatechin, showed zero and/or the lowest activities against pancreatic lipase (IC50 > 20 microM). These data suggested that the presence of galloyl moieties within the structure was required for enhancement of pancreatic lipase inhibition. It is well-known that flavan-3-ols are polymerized by polyphenol oxidase and/or heating in a manufacturing process of oolong tea. Oolonghomobisflavans A and B and oolongtheanin 3'-O-gallate, which are typical in oolong tea leaves, showed strong inhibitory activities with IC50 values of 0.048, 0.108, and 0.068 microM, respectively, even higher than that of EGCG. The oolong tea polymerized polyphenols (OTPP) were prepared for the assay from oolong tea extract, from which the preparation effectively subtracted the zero and/or less-active monomeric flavan-3-ols by preparative high-performance liquid chromatography. The weight-average molecular weight (Mw) and number-average molecular-weight (Mn) values of OTPP were 2017 and 903, respectively, by using gel permeation choromatography. OTPP showed a 5-fold stronger inhibition against pancreatic lipase (IC50 = 0.28 microg/mL) by comparison with that of the tannase-treated OTPP (IC50 = 1.38 microg/mL). These data suggested that the presence of galloyl moieties within their chemical structures and/or the polymerization of flavan-3-ols were required for enhancement of pancreatic lipase inhibition. 相似文献
24.
Kittaka-Katsura H Ebara S Watanabe F Nakano Y 《Journal of agricultural and food chemistry》2004,52(4):909-911
A Japanese fermented black tea (Batabata-cha) contained a considerable amount of vitamin B(12) (456 +/- 39 ng per 100 g dry tea leaves and 2.0 +/- 0.3 ng per 100 mL of tea drink). A corrinoid compound was partially purified and characterized from the tea leaves. The patterns of the purified compound by the silica gel 60 thin-layer chromatography and C18 reversed phased high-performance liquid chromatography were identical to those of authentic vitamin B(12). When 20 week old vitamin B(12) deficient rats, which excreted substantial amounts (about 250 mg/day) of methylmalonic acid in urine as an index of vitamin B(12) deficiency, were fed the tea drink (50 mL/day, 1 ng of vitamin B(12)) for 6 weeks, urinary methylmalonic acid excretion (169 +/- 29 mg/day) of the tea drink-supplemented 26 week old rats decreased significantly relative to that (250 +/- 32 mg/day) of the deficient rats. The results indicate that the vitamin B(12) found in the fermented black tea is bioavailable in mammals. 相似文献
25.
Kajiya K Hojo H Suzuki M Nanjo F Kumazawa S Nakayama T 《Journal of agricultural and food chemistry》2004,52(6):1514-1519
(+)-Catechin derivatives with different alkyl chain lengths were synthesized from (+)-catechin and various straight chain alkylaldehydes in the presence of methyl mercaptan, and their antibacterial activities against Gram-positive bacteria were evaluated. The antibacterial activity increased markedly with elongation of the alkyl chain lengths of the derivatives and reached a maximum at a chain of four to seven carbons. Subsequently, interaction of the (+)-catechin derivatives with a model membrane using liposome was investigated. The derivatives with a chain of three carbons or more were found to have very strong affinity for the membrane. The injury action of the derivatives against the membrane was examined with liposome in which calcein was enclosed as a fluorescent indicator. The leakage was observed in the derivatives with chain lengths of four carbons or more. Particularly the derivatives with chains longer than five carbons are considered to destroy the liposome membrane judging from the degree of the fluorescent leakage. These results implied that the lipophilicity and disrupting ability of the (+)-catechin derivatives to the liposome membrane participate in their antibacterial activity. 相似文献
26.
27.
M Haritani S Ishino M Oka M Nakazawa M Kobayashi M Narita T Takizawa 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1989,51(6):1137-1141
Immunoperoxidase technique was applied for pathological study on naturally occurring pneumonic tissues of calves from which Pasteurella haemolytica was isolated. Multifocal necrosis occurred in the lungs of 25 out of 42 calves (59.5%) and P. haemolytica antigen was detected in 22 out of the 25 calves (88.0%). The calves were divided into 3 groups according to the number of P. haemolytica isolated. The positive rate of the bacterial antigen detected by the technique was 66.6% (28/42) on the average, reaching up to 85.7% (18/21) in the group from which the largest number of P. haemolytica was isolated. 相似文献
28.
Keiji Tanaka Jeffrey G. Scott Fumio Matsumura 《Pesticide biochemistry and physiology》1984,22(1):117-127
The nature of the picrotoxinin receptor was studied using the central nervous system (CNS) of the American cockroach. It first was confirmed by using an electrophysiological technique that the abdominal nerve cord of the American cockroach was sensitive to picrotoxinin. By using a binding test it was determined that the picrotoxinin receptor in CNS of this insect had a higher affinity toward picrotoxinin and heptachlor epoxide than the corresponding receptor in the rat brain. Also, the cockroach brain preparation had a higher percentage of specific binding in the total binding, making this material suitable for receptor studies. By using a sucrose density centrifugation technique, it was determined that the fraction sedimented at the interphase of 1.0 to 1.2 M sucrose at 100,000g contained the highest level of specific binding site. The receptor showed a sensitivity to all insecticidal cyclodienes tested, namely photodieldrin, oxychlordane, endrin, heptachlor epoxide, γ-chlordane, dieldrin, aldrin, heptachlor, and isodrin (expressed in the order of potency). Among four BHC isomers, the γ-isomer showed the highest potency to bind with this receptor. 相似文献
29.
Genetic and phylogenetic analysis of glycoprotein of rabies virus isolated from several species in Brazil 总被引:10,自引:0,他引:10
Sato G Itou T Shoji Y Miura Y Mikami T Ito M Kurane I Samara SI Carvalho AA Nociti DP Ito FH Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(7):747-753
Genetic and phylogenetic analyses of the region containing the glycoprotein (G) gene, which is related to pathogenicity and antigenicity, and the G-L intergenic region were carried out in 14 Brazilian rabies virus isolates. The isolates were classified as dog-related rabies virus (DRRV) or vampire bat-related rabies virus (VRRV), by nucleoprotein (N) analysis. The nucleotide and amino acid (AA) homologies of the area containing the G protein gene and G-L intergenic region were generally lower than those of the ectodomain. In both regions, nucleotide and deduced AA homologies were lower among VRRVs than among DRRVs. There were AA differences between DRRV and VRRV at 3 antigenic sites and epitopes (IIa, WB+ and III), suggesting that DRRV and VRRV can be distinguished by differences of antigenicity. In a comparison of phylogenetic trees between the ectodomain and the area containing the G protein gene and G-L intergenic region, the branching patterns of the chiropteran and carnivoran rabies virus groups differed, whereas there were clear similarities in patterns within the DRRV and VRRV groups. Additionally, the VRRV isolates were more closely related to chiropteran strains isolated from Latin America than to Brazilian DRRV. These results indicate that Brazilian rabies virus isolates can be classified as DRRV or VRRV by analysis of the G gene and the G-L intergenic region, as well as by N gene analysis. 相似文献
30.
Nagata T Koyanagi M Tsukamoto H Saeki S Isono K Shichida Y Tokunaga F Kinoshita M Arikawa K Terakita A 《Science (New York, N.Y.)》2012,335(6067):469-471
The principal eyes of jumping spiders have a unique retina with four tiered photoreceptor layers, on each of which light of different wavelengths is focused by a lens with appreciable chromatic aberration. We found that all photoreceptors in both the deepest and second-deepest layers contain a green-sensitive visual pigment, although green light is only focused on the deepest layer. This mismatch indicates that the second-deepest layer always receives defocused images, which contain depth information of the scene in optical theory. Behavioral experiments revealed that depth perception in the spider was affected by the wavelength of the illuminating light, which affects the amount of defocus in the images resulting from chromatic aberration. Therefore, we propose a depth perception mechanism based on how much the retinal image is defocused. 相似文献